Crawl Spaces : Good vs Bad

[@ForbiddenUser403]

I used to have a really nasty crawl space under my house... That is until my street's sewer line backed up, and back pressure forced the entire street's sewage into it once it popped the main line off. I couldn't even get a plumber to go down there to repair the broken pipe until I had a restoration company come in, which is basically a hazmat team to clean up the mess. What they did in the process was basically totally modernize my crawlspace, installed a vapor barrier, put down clean fresh sand to replace all the contaminated debris they removed. The best part was because it was caused by a blockage in the city's lines, they footed the bill for the entire process. Almost 10k$ between the restoration and the plumbing bills, and now I've got a beautiful crawlspace that makes it a dream to get down in when working on plumbing and what not. I've never been so happy over a sewage backup before.

[@rainmaker3700]

LOL, the 10K you did not spend was a frigging deal!

[@rodneyhammon1793]

Forbidden User w wow

[@shimes424]

That's why they'll also pay to upgrade/update your sewer system to the street to avoid these problems

[@Alex.Smoake]

That’s a happy ending!

[@johnknoefler]

I just quit working with a plumber partially because of these issues. One house we were called to he boasted how he had done a main sewer line repair at the house but we had to go back to clear the drain again. What I found was that he had simply put in a cleanout just inside the access but when he ran the snake he broke the rest of the old 3 1/2 inch thin sewer. So, for years the sewer had drained into the very sloped crawlspace. The air was so bad possums had gone in and died from the gas. We had to pump out the sewage and then make the repair. Later the owner had to replace the rest of the drain all the way to the street. A large tree had put roots into the line. Crawlspace from hell. I get sick with just remembering.

[@thepinkerton657]

I spent over 25 hours in my crawl after watching this the first time. Went from vented with roll bat underbelly, no sump and exterior access to sealed, conditioned, rigid foam perimeter, interior access and a sealed sump pit at each end. Watching again because noone else cares but us

[@Tomtom9401]

Can you share in photos?

[@pullingweeds-managingcptsd252]

I am The same as you… and a 49 year lady who uses a walker and wheelchair. I cannot afford to hire anyone and and I care about my home, my mortgage makes me be able to afford a decent but modest place to live. There are wires all over the ground and that frightens me- the ductwork and plumbing are nicely hung/ supported… but past workers left old materials scattered, it went and moist.. a couple of 12inx12 in (6 in depth) shoveled? Areas… that have little pools of water.. the rest is just damp and thick muddy by the back side of the house brick foundation line. I am overwhelmed and not sure where to begin. Cleaning for sure. Checking for any dangerous wiring, I have installed a French drain in my front yard and am thinking I should put one in along the back of the home. Alternatively, my home slopes downward, so perhaps a vapor barrier and concrete poured over. Being disabled and on a fixed income is not ideal right about now! 😂

[@thepinkerton657]

@@pullingweeds-managingcptsd252 start with outside grading and extending your gutter down spout run off drains

[@pullingweeds-managingcptsd252]

Yes I can take some photos it’s raining today so I was going to do a little bit of investigation depending on how hard it rains I was under there yesterday and did find a couple of skeletal remains luckily not human but I’ll joking aside last time I was down there I was electrocuted by a live wire which we had an electrician come out and cap off. I now know that I need to turn off the main breaker and clean the wire mess up I think mostly as a lot of cable wire that’s just been cut through the years and satellite dish wiring at Cetera. Anyway I will see if I can get down far enough today I’m a little achy due to the rain on top of my normal issues but if not I have a window that was busted out that I built a frame and put in a pane of glass and I’m insulating the glass and getting ready to put that into the brick area that contains the metal frame for the window that is actually embedded into the construction so I am also adding a layer of foam insulation board to the back of it and installing the window in front of it. But I will not install the insulation board until I finish working because until I permanently install the window that I built and then caulk it in etc. I can take it out for work purposes and ventilation. I can actually crawl through the little holes that divide up the old window that had acrylic in it if I really wanted to which I don’t but since I can crawl through it means that I can also lean through to take pictures and at least zoom in so you can get an idea even if they’re not the best quality. One question that I do have is that I want to replace the insulation because it is just hanging down probably from aids and rodents or other critters in some places the wooden floor joists and the wood flooring are still sound I have already checked. This past winter we did actually have a Water main break and the city just left it for a week because they said that the man who needed to cut the concrete was on vacation mind you they only needed to cut 2 ft.² but anyway it flooded our yard which I trench to my French drain which I had already installed and then hi later had to go back and trench from the backyard where the French drain lets out which is actually the side yard and it’s past the house of course I had to trench down to the woods behind our house and we live on 3/4 acre so it was a very tedious long job. I re-graded the front yard when I had to repair all of the trenching that I had to do to save my crawlspace because it was so very flooded but the area most affected is the area that I didn’t have to trench and so I actually was able to quickly add soil and build up the front side yesterday in the area that is most affected. I totally went on a bunny trail there but anyway insulation so I want to tear down the old road yucky insulation and I’m thinking insulation board. Opinions? By the way I apologize for the run-on‘s and grammar issues but I have nerve damage and can’t feel my hands although they are functional but typing on my iPad is really creepy so I speak and it turns into a book unfortunately and it turns into conversational writing::: so I just wanted to explain I’m not just being a flake. Lol

[@pullingweeds-managingcptsd252]

@@Tomtom9401 I am not sure how to share the photos here?

[@SearTrip]

Not a builder, just a homeowner. I had just changed my dehumidifier filter in my crawlspace when I came back up to you having posted this video. I’d been worried about it for a while, and this video was the straw that broke the camel’s back and got me moving. We had most of the problems you talked about. We found a company that encapsulates existing crawl spaces in our area. They just finished today. Not the most sexy space to spend money in the house, but I feel much happier about the sealed, drained, encapsulated area under the house now.

[@sugumargovinda]

AND CONDITIONED

[@matt8863]

Matt...Most of the crawlspaces that I've ever seen, were in coastal communities in mapped flood zones where basements in these areas were prohibited, yet built prior to base flood elevation (BFE) standards being incorporated in the building codes. In certain communities here in the northeast, FEMA had recently completed flood map revisions, which placed existing homes with basements in a special flood hazard area (SFHA)...Those homes have lost significant value as the flood insurance premiums are cost prohibitive for most. The best recommendation for those facing this dilemma, is to move all of the mechanical systems, and fill their basements in to surrounding grade. That in itself will significantly reduce the flood premium, but not completely solve their issue as the (new) lowest floor elevation may still be under the BFE for that area. Flood insurance rates increase exponentially once a determined (by an elevation certificate) lowest floor elevation drops below the surrounding grade on all sides. Many people would benefit from you posting a good tutorial on how to accomplish an affordable basement to a FEMA compliant crawlspace conversion.

[@sergii_contractor]

Right, can't build no basements by the coast. Also when you are in the flood zone, not everyone want to build houses on piers as it will require to climb staircase, so you can see tons of older houses built on 2ft ventilated crawlspaces that currently are getting encapsulated by local contractors due to high humidity.

[@johnlimongello5716]

I was a home inspector for 5 years in Georgia... Heard a story from an old-timer that actually found a human skeleton in a crawl space. He had to leave immediately and called the police... Turns out they buried grandma in the crawl space because they couldn't afford a funeral. Thanks for the video... I appreciate the info and totally agree that crawl space should be conditioned spaces.

[@danrichards496]

John Limongello I wonder if anyone is buried in my crawlspace.

[@comcfi]

Oh I hope she was ok

[@88KeysIdaho]

@@comcfi No. She was dead. Grandma was DAYD !

[@Crysisplaya]

@@comcfi she was she’s just chillin

[@andreaberryman5354]

A husband murdered his step son and buried him in the crawl. The new owner's wife went down to check something and found shoes poking up. She tried to grab them but couldn't. Husband checked and discovered femurs, so cops were called.

[@volundrfrey896]

I've been in a crawl space here in Scandinavia in a house that was build the year 1900. It was great. It was well ventilated and the ground drained well. No plastic to trap water, so very little rot or bad odours even after 100+ years. The entire house was just extremely well built and throughout.

[@SilverPlum]

I'd love to see details, video & stills, of the construction of your house.

[@6stringsandapick]

I love retrofitting old crawlspaces with closed cell foam and vapor barriers. Massive benefits in efficience and air quality.

[@ErnieTessein]

If you have a vented crawlspace and want to convert it, what is the best way? Vapor barrier the ground (I have concrete) and close cell foam the walls?

[@phildnyc1]

I bought a house in upstate NY with a crawl space - its dry with concrete floor and cinder walls, insulated with spray foam under 1st floor but still has a few vents - not perfect (yet) but not wet and not cold. Since its my first house and haven't seen many crawl spaces before, I wasn't sure of quality of the space so its helpful to get a frame of reference for what is good and what to avoid or fix. Really helpful video.

[@TravelAboveMe]

I'm an engineer by degree and an industrial project manager by profession, and have been eager to get into home construction for awhile. As a segue into the field, I purchased an 1920's home a year ago and have been renovating it solo with immense study of codes and best practice, a lot of which comes from Matt's video's. It really makes me wish my early years were spent training under someone like Matt who clearly knows plenty of the tried and true methods, but is happy to entertain the up and coming technologies as well. I love the videos and appreciate the time put into making them - this is an excellent channel!

[@seanm3226]

The one takeaway from this video...is that money is no object.

[@Joemama-km9np]

Same thing I was thinking, when you got money then things will be done by the most expensive professionals. I've been to enough third world countries were I've seen people live in those nasty crawl space conditions and call it home.

[@layicorn]

Where's the money Skylar

[@anotherdayforrj]

@@layicorn Skyler..... WHERE IS THE MONEY!!??!

[@AHPpilot]

The whole point of the channel is for best building practices, though, not just the most cost effective. You can take these principles and make your own compromises based on your own budget.

[@glasser2819]

crawl spaces are excellent to vent RADEON gases ! It's amazing to see...: - cheap particle floor joist when you consider labor cost - cheap plastic vapor barrier instead of a rat-slab to prevent uninvited winter guests - slab on grade needs to be well insulated to prevent condensation or moisture migration and ground radeon Besides wood structure will want ho wick moisture until it simply rots right around 10YRS 🤗

[@MoneyPitCastle]

Whenever I'm looking for a video on any subject, Matt akways has one. Thanks for this

[@KX6D]

I'm the second owner of a Southern CA house built in 1959. I bought it in 2019. One of the first fixes was to replace the closet mounted heater with an attic mounted HVAC system. This was to allow us to use that heater closet to extend the small shower in the master bedroom. Imagine my surprise when I removed the heater only to find that for 60 years it has been drawing the air in from the crawl space! No return air! That means all the air that comes in has to go out so it leaks like a sieve! Lots of work to do!!

[@JohnVance]

This is so timely for me! I've got an old house with a really terrible crawlspace. Have been looking at encapsulation or maybe even a full dig-out. I love the drop-down ladder! It's like attic stairs in reverse.

[@nsuddeth91]

Absolutely love this video! One of my primary resources for learning home improvement methods is This Old House. However, I've learned by now that crawlspaces are apparently non existent in the New England area and thus they virtually NEVER have episodes pertaining to crawlspaces. Thanks for making this video, nice to get some valuable info. You've given me a lot to research further now.

[@sirwilliam51]

You just gave me a great education on a property that I'm considering. It has some serious moisture damage from accumulated time and probably venting down in Louisiana. I'm having an inspector go down and look at the damage to see if the entire floor joists need replacing or just several along with the subfloor. You convinced me to get that dried out, replace the damage and seal up the foundation to make it a place for my grandson to inherit.

[@areyoujelton]

sirwilliam51 you’re a great grandfather, just saying... My wife and I are currently living in my grandparents’ old house and we love it! Great memories and we are making new ones.

[@annechovey2492]

Thank you Matt! We bought a fixer upper and the first thing we did was spray open cell in the attic, 2nd thing we did encapsulate the crawl spaces, We have yet to insulate the spaces, still researching the most economical way to do it right i.e. closed cell vs. XPS with spray foam gaps, remodels can get out of hand cost wise, and we aren't sure if we want to invest in quality and stay here or do it well and sell, so much of what we do is determined by the market and our jobs. Thanks Matt for everything you are doing especially recently.

[@P_RO_]

If a crawl space is ventilated properly (which few are) and the exterior of the stem walls are waterproofed well (which even fewer are) then a crawlspace will not have moisture problems. Those who want to "sell" encapsulation overlook the historical buildings which didn't have sealed crawlapaces but were on piers and totally open to airflow. 150 - 200 years later the original wood is still in perfect shape which would be impossible if encapsulation was the necessary answer. The best value answer is to address the moisture problems and ventilate well, then insulate the floor with unfaced fiberglass. All that encapsulation does is prevent you from seeing rot and termites when it's new and more easily dealt with. Any moisture which gets into the wood now can't get out. You don't want an air-tight house if you want it to last. Look to the past and learn- it worked then and it still works.

[@noampitlik2332]

I completely agree after 17 years of experience.

[@markme4441]

P ro, that worked in houses that were all solid wood with no a/c , but not anymore, vented crawl spaces in a insulated air co ditioned house is a bad design

[@Devilsnowballs]

As a plumber I do hate crawl spaces however after crawling and them for years they become like a plumber's home. And all I can say is there is a reason that commercial is usually done on slab and has concrete slab. However I want to add to this then when you have a concrete slab that you lay all your pipes in there's ever any major issues you got to start chopping up that concrete slab. The project gets a lot more expensive and a lot more extensive when you don't have a crawl space. So from a maintenance perspective crawl spaces are often really handy.

[@brianwideman2342]

Well said , crawl spaces built, right cost alot less.

[@rikityrik]

You and your friends work looks phenomenal.👍 I love the indoor access to the crawl space. I hate going in mine it’s nasty, especially knowing I’ve found scorpions down there. In 2012 we were in a bind and decided to renovate this little century old farm house. I’m thankful for it but the crawl space is the number one reason why us throwing money in this old place bothers me because it’ll never be right. That said, I can’t really complain, and am thankful to have a roof over our head. But I agree, if at all possible steer clear, because if it bothers you to begin with, it probably isn’t going to get better.

[@kennieloo6357]

I’ve watched this video before but it just didn’t click. Glad this resource is always here. Thanks a ton!

[@dosadoodle]

I don't build, but Matt's videos help me think about the kind of home I want to live in, especially if we hire someone to build us a home rather than buy a pre-owned home.

[@grendelum]

Dosadoodle - I’m in the process of tearing down my 100+ year old home here in SW Florida (it’s so grossly inefficient and while 4k+ sqft uses space terribly) and building a new one. These videos have been a goldmine for me as I’d never thought about these things until now. One interesting bit, I’m going with a company that takes my blueprints and builds the house shell in ~65 pieces out of a sandwich of concrete board and 8” of closed-cell foam... it looks and builds just like a normal house except it’s airtight with the windows in less than a week !! Not to mention the Herr (I think? The insulation score) score of 50 with the triple glazed hurricane proof windows... with the Tesla SolarRoof and PowerWalls (and a bunch of other whizbang renewable tech) I’ll never repeat the 11 days without power we suffered after Hurricane Irma !!

[@rodneyhammon1793]

You definitely have the best home building show around!…I’ll be moving to Florida in 2021...and I have so many notes and tips on new construction from this channel...I’m so very grateful for all your hard work on these videos, which in turn will help me when I have my home built!…thank you!...

[@stevepark1930]

You didn't mention anything about air movement in a sealed or conditioned crawl space. I do believe a sealed crawl space is the way to go, I have completely sealed my crawl space and it is fantastic, (no shoes in my crawl space, Lol), but also it is now part of the air of the entire house, so part of the heating and cooling system. without air movement you can have moisture build up? Yes? or adding a dehumidifier in the crawl space to regulate the humidity. Love your input, Thanks for the video.

[@offgridnorthwest]

Good video Matt. I did a retro system on my old house in Northern Idaho a few years ago. Took a wet, dank, dirty, smelly crawlspace and added a powered vent system underneath a white vapor barrier that turned the space into a magical place. It improved air quality in the home dramatically. When I sold the house, the buyers inspector arrived to look things over. He asked where the crawl space access was and I showed him. I had installed lights under there as well. It gleamed like a diamond in the sky and he literally said, "Oh I love you!" He was so happy to find that space clean, neat, tidy, and dry. I think I spent less than $500 for the entire project including the power vent system (radon gas was high and that was main priority for powered vent system).

[@emerquiazon9078]

OffGridBear I’m impressed with your retro system work, would it be possible to get additional information especially about your power vent system? My email:[e-mail]. Thanks!

[@offgridnorthwest]

It's pretty easy. I purchased a Fantech 4" vent fan, don't remember exact model. My house outside footprint was 24x42 so I just purchased a 12 or 20 mil (can't remember) radon/moisture membrane online. It was 25x50 which fit my situation perfectly. It allowed me to bring it up the wall about 18 inches on every side where it was attached with a drill and plastic fasteners to the block wall, then that was overlayed at the edge with special tape to seal it all up. before installing the barrier I placed perforated drain pipe (just laying on the dirt) down the long axis of the center of the crawlspace. Over that I placed some of that green erosion control poly blanket stuff you see along highways after construction. It was the cheapest air gap I could find. I think I got enough to do the entire space for $40 on Craigslist. Then the vapor barrier went over that. My barrier was black on one side with a mesh sandwiched between the white layer on the other side. I installed it white side up. The perforated pipe attached with a rubber boot to standard 4" PVC pipe that was sealed before it exited through a hole I made in the wood part of wall and then went up the side of the house to the vent fan. I had an outdoor electric plug on that side of house and I just tapped into that circuit for wiring. It was really pretty easy. I actually lived off-grid at the time so I put a switch on that fan that allowed me to turn it off if needed. It didn't draw very much power at all though and was left running all the time. If I was to do it over I would dig out a little channel for the pipe to drop into so there wasn't a hump in the middle of the floor. I'd also have placed 2" foam insulation boards down on the ground before putting in the pipe, air gap, and barrier. I was thinking only about moisture/gas control and not about creating a crawlspace that was part of the heating/cooling space and it would have made the house a lot warmer in the winter I think if I'd done a full insulation down there. Otherwise I was very happy with how it did vapor/gas/moisture control.

[@emerquiazon9078]

OffGridBear Thanks so much for the info.

[@2Truth4Liberty]

I have in an old one story stone house (2 foot thick stone walls) with a 2 foot(max) crawl space. Water under there rooted the entire wood joist floor. The only utility under there is a propane line running from the man door to a wall furnace. It' in the midwest with both COLD winter and HOT summers. Should I condition that space and put new wood floor OR fill it and pour a concrete slab? Which is cheaper? Which is better?

[@confidentlocal8600]

@@2Truth4Liberty Have you fixed downspouts and site grading first? Also, a Santa Fe Compact2 dehumidifier worked wonders for my crawlspace.

[@felixsvensson5265]

You forgot to mention underpressure. That's how we do them in Sweden nowadays. Basically the blowout fan is in the crawlspace and the intake vents are in the house. That creates an underpressure which makes sure that the air from the crawlspace doesn't go up into the house

[@rickl6697]

I was going to ask Matt about the foam and or the insulation board covering the top of the wall preventing termite inspections but after looking down through the comments it's apparent he doesn't answer any comments. I'm sure he's busy.

[@jameslambert5049]

Great video. Lot's of details that educate. I really like examples of large budget builds and advice on retrofitting our current houses. You really do a fantasic job with these. Always look forward to the next one. Thanks

[@Wood-Renovations]

Really like this format Matt! So much information and multiple scenarios! Love it! Thanks for all of your videos and the knowledge you put out!

[@mikewencel686]

Thanks Matt! I'm not a builder but always wondered why you would do that. I'll do a slab on grade in Idaho with radient heat.

[@Stormycloud701]

Crawl spaces are big here in Canada(Manitoba anyways) mostly ICF with ridged foam 4x8 around the perimeter. Poly inside with sand or pea stone on top and sump pit with weeping tile all around. Works great for the furnace , hrv , ducting, plumbing, electrical ran easy, hwt , jet pump, etc.

[@shimes424]

5:04 ditto! Was just about to suggest this! So glad the crawlspace is concrete, though a little rough and it's pitched to the corner sump pump but it could be better, lots of puddles after a water tank leak

[@andreaberryman5354]

Mine is beautiful and typically dry, but it's an old one, when homes were built a little better. Basements are subject to hydrostatic pressure which isn't great. My footers are partially exposed in some places-can't find anything about whether that is bad or not. I really like the job done here with the concrete support piers.

[@ThomasDiy]

I live on top solid limestone rock. If I would try to dig a halfway decent basement. It would probably cause me $100,000 in excavator fees along with hammer attached. Personally I think code should require you to install neting under a house to provide insulation from falling down.

[@googleuser6875]

Hi Matt, This brings a lot of questions to my mind. We bought a home in NW Pa a few years ago that was built on a stem wall with a crawl space. There is an addition on the back that is used as a "sun room" (all windows) that is not set on the original stem wall. Here is the scenario. The original owner/builder vented the crawlspace according to local code. When he added the "sun room" it was placed on pillars with cement board sheathing. Prior to our purchase he was required by inspectors to vent that space as well, due to mold issues. The original building with venting has no insulation in the floor joices, and strangely/oddly/hysterically, he placed batt insulation on the stem walls (obviously doing nothing since the space is vented (correct?)), there is no moister barrier either.. There is a return air duct in this space, but the warm air runs through the attic. This is a very short crawl space and to be truthful I doubt the local code enforcers ever heard of a "conditioned" crawl space. I was considering putting batt insulation under the floor but after watching this video I'm confused about that. The floor is cold year round, and of course very cold in winter. I'm not sure if "conditioning" the area is possible because one of the concerns in this area is Radon gas. Most of the codes I've seen require venting to prevent Radon build up. Fact or fiction? I don't know. So what can I do to insulate the floor in this climate? Thanks for any advice.

[@whommee]

Amen,, from the south here as well,, was practicing building sealed , waterproofed conditioned crawl spaces 30 years ago,, folks thought it was crazy then,, and had more than a few debates with different building inspectors back then,,, best practice for a crawl space is a graded ,, base, stone sub base,, heavy moistire membrane,, insulation board under a lean concrete slab,,, perimeter drain below footing level,, waterproofed sstem walls,, with continuous perimeter foam insulation starting at footing level,, continuing up to stay in same plane as exterior wall foam board insulation,, ,,, also have plumber install a floor drain or two in crawlspace slab ,, minimal concrete slope in case of leaks,,, but have a trap primer installed in those floor drains,,, In our high humid climate ,, have mechanical design to include a portion of return and a small supply air to keep the space de humidified.. it works,, saves energy,,, more comfortable house,, IAnd more importantly compltely stops mold mildew issues to structure,, and as you said ,, eliminates the critter problem,,, just be sure the crawl space entry doors are insulated and instaaled with same care as those at the living space !

[@fm15243]

I got a house from 61 and the crawl space is mint sound like everything you said

[@Alex.smiffy]

My 100 year old waterfront cottage in New York stands directly on bedrock and has a fairly short crawlspace. I turned this cottage into my year-round home so insulating and utilizing the crawl was important. I have done an encapsulated/ conditioned space using materials from Crawlspace Depot online. So far, so good through three zone 4 winters and summers. I am monitoring summer condensation and may decide to add a crawlspace dehumidifier in the future. (I added wiring to that area for lights and a future dehumidifier, if needed.)

[@donaldguilbault7433]

Hey Matt, I am a cabinet maker and trim carpenter so I'm not an expert in all building sciences (though I like to be well informed) but was wondering what advantages are there are to building a crawl space rather than a slab? I guess the slab house is less expensive to build and more accessible for aging people where steps would cause some mobility issues. I wish I lived in Austin I'd have a job on your crew. Love what you're doing. Keep up the good work and pushing quality and craftsmanship.

[@eliinthewolverinestate6729]

Have you ever taken a close cell foam float out to the lake? They do become water logged. If you have closed cell foam up against a sealed masonry foundation it can become water logged. Masonry needs some above ground area to dry out. Just saying. Rockwool up against masonry is a better choice. To allow things to breath. Are roof vent baffles required by code down south? After I finish supporting my old house in the crawl space. I will be rolling out some vapor barrier. Tempted to spray foam that brick along outside wall in the crawl space after a lime white wash.

[@theradonpros]

Don't forget Radon! If in a high radon zone, do some research or bring in a radon professional when building crawlspaces. The better and tighter you build a house the worse radon concentration can be within the home. At this stage with a membrane or slab installed you can get a complete radon system for around $500-$1000. Additionally, it is much easier to lay that membrane with taping during initial construction. You can also plan to install piping through the house up to the attic area which eliminates uglier exterior radon systems. Talk to the homeowner and discuss getting a radon professional in to evaluate your situation.

[@billybobjoe198]

Hmmm, a radon company shilling for radon control. Radon is literally a non issue. But you have shilled so hard that pretty much anyone buying a house gets a radon test and freaks out now.

[@Babarudra]

looking at a house with a crawlspace. I haven't been in it yet, but trying to get some preemptive information on how to make it better. I doubt much has been done to make it good. It was built in 1890, so who knows what I'll find. This was the first video of yours I've seen that deals with crawlspaces, I'm hoping that there's more. I'll be rewatching your attic videos too. Thanks for always having great information.

[@Hypercube9]

Okay... tell me if this sounds right. I live in Michigan and I didn't use to have any water issues in this home. There was card board on the basement floor to make crawling easier so I would have noticed. Then my neighbors HUGE tree fell down and now I DO have water issues. The tree can no longer soak up all the water I guess. If it matters, we live in the middle of a hill that's built like steps. I'm thinking before I do any sort of crawlspace renovation I need to install a french drain in the backyard to get the water to go around the house down to the street. Water from my neighbor's yards runs into mine I think given that I'm downhill. The crawl only has 3 openings: a tiny air vent that might be needed by the furnace, a much larger opening that I think might have been needed to install the furnace, and the door (which is also not very big). I plan to close the second opening (I've kept it in case I need to pump in fresh air before going down there.) and I'm looking to buy a better door than what I built for the entry. Do I need the other opening? Doesn't the furnace need oxygen to burn fuel? If it helps I can run a pipe straight to the vent and spray foam that. After that I was planning on doing a thin layer of concrete on the floor and possibly enclosing the furnace in a box of some sort. There is definitely some crawlspace air being pumped into the house! I've taped HEPA filter material over the vents to reduce it but that's just a bandaid. I was planning on going down there with a leaf blower to clean out any old dust and stuff, sealing up the holes, running an air filter under there for a few months, and replacing all the old sheet metal pipes with insulated ones. Would I be better off trying to move the furnace to the attic which is also open air? Would I then also need to enclose the furnace up there? Or should I abandon the furnace and install a heated floor? Or do something else, etc.? Any help would be greatly appreciated!

[@ThinkLiveLife]

One thing I would really like to hear more about is how to deal with up-gassing requirements. I get the theory of 'seal everything and condition the crawl space' but many municipalities will not allow you to fully seal a vented crawl space under the argument of up-gassing. How can these concepts be put into practice?

[@MrSparkums]

Best Building & Building Science info on the intranets! Thanks Matt!

[@Mixwell1983]

Coming from a slab foundation in CA to my house with a crawl space in TN soo far I dislike the noise from walking around. A benefit is my plumbing lines are all easy accessible vs being under a slab.. my old house was all old cast iron, woulda been a lot of money had i had to repair it.

[@jonz769]

I live in southern BC, right on the WA border. Climate Zone 4. The 3' high crawl space in my 25 yr. old home has poured concrete slab and walls. The walls are always dry but there are lots of damp spots on the floor (no puddled water), a fair bit of efflorescence and some mold spots. There are no rodents or termites. The perimeter drain pipes are fine - I have them inspected/cleaned every 5 yrs. The heating system is forced air so I had the furnace guys cut vents in the supply and return air ducts a few years ago. After tons of research, I am DIY'ing a clean-up with Concrobium, and then sealing the concrete with a chrystalline sealer like Xypex High'N Dry. My question is about the rigid board insulation for the walls. I'll probably use R10 but I can't get a consistent answer on whether I need it to be foil-faced. I'd appreciate your opinion on my plans and on the insulation. Thanks! Jon

[@stevensims3342]

Its crazy. My folks had their double wide installed back in 85' I think. Wayy before people were really worried about leaving them up high enough to actually crawl and not shimmy under the house.

[@thomasmorrison3279]

With encapsulation, you still need a dehumidifier to prevent changes in humidity in the crawlspace.

[@TheOneWhoMightBe]

Unless your site is rock, or the budget is tight, what is the rationale for only building a half-basement rather than a full one? For only a few percent extra on the cost of the build you double your floorspace (for a single story home) wheile building a half-basement you seem to incur a lot of the same costs but don't get nearly as much utility out of it.

[@1121494]

Or even cheaper you just put the ground floor a bit higher and make a full storey for utilities out of a half basement.

[@gfriedman99]

Trying to figure that out myself. Ive got a 4 ft high half basement here in CT. I guess if they made it 7 ft that would either mean a couple extra steps to the front door or they would have to dig out the extra 3 ft and maybe hit water? I don’t know but if not then it just seems foolish to build this way.

[@tycox8704]

I despise any space that is below ground level. Ground water is a constant concern, and expensive to control. I much rather have a crawlspace built on a slab.

[@jeffreyquinn3820]

I'm curious if crawlspaces have fewer radon gas issues than basements.

[@The2tothe3]

Moisture/vapor condenses on the warm side of an insulated partition. Closed cell on the floor of a south crawl space that also has cold winters, such as zone 4, Tennessee, South and North Carolina and many miles north or south of there can cause condensation above the insulation. Be sure you take these comments with a very specific knowledge of your local conditions.

[@jean-clauded5823]

I'm in Dallas and I'm about to replace all of the beams under my house because of wood rot. The sub floor is fine, but the prior owner did a closed cell foam under the floor, sealing in any moisture that migrated down from the living space. Anyone ever spill a glass of water? If so, now you have moisture that will get stuck on top of the closed foam, and rot it. This is why my beams failed, but the plywood decking did not.

[@Anything.is.Possible]

I have a crawlspace 2000sqft built 12yrs ago. The walls are 8inch x 4ft poured on a 2ft x 6inch footer. I am in the middle of retrofitting it now. I sanded and sealed the whole underneath and floor joists. I installed a sump pit in case of an emergency line leak. The crawl floor has plastic then 4inches of pea gravel. When it rains alot water will seep a little around the edge on top of the footer. I have used hydraulic cement to slow it down but still not 100% so I need to fix that before I encapsulate. The vents I have been opening when it's under 45% humidity. I am going to install little windows in front of my vents as a easy way to vent or seal.

[@billhill3526]

I know a few places where I live on Vancouver Island that have a heated slab on grade with 2 heat pumps. One for the heated floor and the other for forced air up stairs. It could also be a geothermal system run on solar power. On top of that, you can have a heated driveway, so you don't have to shovel snow. That would be handy if you had a steep driveway and you need to "get going".

[@LarsSveen]

Curious what you think about the construction of my house's floor... My house was built in 1935. It has a unique floor. The walls are adobe bricks but there is a cement slab foundation which goes up about a foot around the perimeter, and the adobe outer walls were built on top of that. There is sort of a subfloor -- they had laid lumber skids across the whole house interior, right on top of the cement slab, and then did tongue-and-groove boards on top of that at a 90 degree angle, then oak floorboards on top of that at 90 degrees to the tongue-and-groove boards. Most of it has fared pretty well. Still very solid, except where there were water leakage issues around the bathroom (turns out the old tub overflow was not connected to anything for decades).

[@sgt_retiredcharlie4102]

So, I've got a 12 year old house in Midwestern Tennessee and I've got one of those nasty, wet crawlspaces where the pink fiberglass insulation is falling out of the floor joints due to moister build up and we're starting to see the first signs of mold. I'm a 100% disabled veteran so I'm on a very fixed budget of just my VA Disability, so I can't afford a $30,000 makeover/renovation (what I was quoted for encapsulation). What would you recommend that I can do or have done to mitigate that nasty air leaking into my vents and to eliminate the moisture underneath my house? Thanks for all the great videos Matt!

[@MrDaryboy]

Great vid. I will say that a lot of people do a crawlspace Instead of a basement for concrete cost. I am one of those people. A question I have is what about a vapor barrier then back fill with gravel? Cheap and should take care of any moisture from the ground.

[@dlwatib]

An uninsulated concrete slab is better in a cold climate than an uninsulated vented crawl space. Why? Because if there is unconditioned air between your floor and the ground, that's going to be colder than the ground itself in winter. Besides, whatever heat (or cooling) you lose to the slab and the ground under it isn't really getting lost. It's just going into a thermal mass where it will get radiated back eventually. That means if you want to go away for the weekend you can probably turn the heat off and it will keep your pipes from freezing. You may also be able to tolerate turning the heat off at night while everyone is in bed. In summer, once you cool down the slab it will help keep your house cool and make your A/C work less. Of course, insulation is better in each case. You don't really want to be heating/cooling the soil under your house even if it does make a good thermal mass. You'd really like to have the heat/cooling right now while you're running the furnace/AC, not after you shut off the furnace because you're leaving for the weekend. You can, and for modern construction you should, insulate under your concrete floor slab with a rigid product. This is probably the preferred method of providing a foundation for a building these days. It really doesn't matter whether you provide a basement or not. If you do, it should have insulation under the floor slab too.

[@lukejackson1871]

Is this a thing? I was just thinking if you could pour a slab over a vapor impermeable barrier and insulator that would change the game

[@pullingweeds-managingcptsd252]

I am The same as you… and a 49 year lady who uses a walker and wheelchair. I cannot afford to hire anyone and and I care about my home, my mortgage makes me be able to afford a decent but modest place to live. There are wires all over the ground and that frightens me- the ductwork and plumbing are nicely hung/ supported… but past workers left old materials scattered, it went and moist.. a couple of 12inx12 in (6 in depth) shoveled? Areas… that have little pools of water.. the rest is just damp and thick muddy by the back side of the house brick foundation line. I am overwhelmed and not sure where to begin. Cleaning for sure. Checking for any dangerous wiring, I have installed a French drain in my front yard and am thinking I should put one in along the back of the home. Alternatively, my home slopes downward, so perhaps a vapor barrier and concrete poured over. Being disabled and on a fixed income is not ideal right about now! 😂

[@pullingweeds-managingcptsd252]

This was meant to be a reply to another comment but didn’t attach? Weird… it was to the person who has spent 25 hours in their crawlsbase!

[@tasmaniandevil7610]

What you need is a hard working man and some good conversation

[@pouetance]

Nice to see how houses are built in the south. Can't imagine not having a basement :-) In Canada, lot of houses now have insulation on the outside of the foundation and even under the slab (except for the footing). This way, you have one continuous layer of insulation all over your house with no thermal bridging.

[@johnclark7406]

Shallow water table is an issue as well. In the South basements are generally walkouts built into a hillside.

[@SpectroOfficial]

Floridian here. I imagine building a basement down here would be too costly considering theres rock just 3 feet under in the majority of Florida. The rock is dried up coral. We have to deal with cutting it out even when we're just putting in fence posts.

[@holdenbeck8636]

Matt I love the videos and seeing how to build something in the best way, but I would love to see more videos of fixing older systems. I have a 1955 house with vented crawl and not sure what to do. I live in NC, so moisture is an issue in the summer. All I have is a crappy "moisture barrier" from previous owner.

[@stevescherer4954]

When I bought a used home with crawl space in GA , the first thing the seller, and the inspector, told me to do was to keep a dehumidifier running 24/7/365 and repair the encapsulation (moisture barrier). There's evidence of old mold on some joists and subfloor, but no new issues. BTW I also keep sticky bug traps along all the walls down there to reduce bug populations.

[@jaisvikt]

Retro style. Perimeter stem wall with ventilation spaces, poured piers with footings, interior perimeter drain with sump pump, ground covered with poly and floors sealed with closed cell to 3 inches. No place for critters to get cozy and fairly dry but air quality not so good but then....I don't live there! Best make sure you've an excellent outer perimeter drain to proper depth with conditioned space because it's sure to get wet in there otherwise.

[@epistrummer]

I built my crawl space with Amvic foam blocks, then used spray foam in the joist bays which is code here in northwest Montana, then I put in a radon system and filled in with 3/4 wash. Black plastic over that and seal it, it has worked perfectly. No mold, conditioned space that stays 64 degrees all year round. Only thing I would have done differently is I would have liked to have a concrete slab instead.

[@jean-clauded5823]

You put your radon system under the plastic? So, how does it do you any good if it is shield from getting any air to it?

[@joulian-m2u]

What I ve seen is the landscaping ( slope of the ground etc.) contributes to the terrible conditions of the house. If folks would quit having the front yard sloped toward the house where the water goes under it that might help. Putting in french drains if it has a slope as mentioned to get water away from house.

[@deathlokmk1]

As an HVAC/plumbing tech I would kill for crawl spaces like these. Here in Oklahoma most of the houses are 60+ years old, no vapor barrier on most houses and your lucky if you have room to crawl after 60 years of settling.

[@jonbarrett9053]

Lots of issues with Spray Foam. #1 Termites and Carpenter Ants love to nest in Spray Foam...so You will never see either of them unless you inspect monthly. #2 Insurance companies are now Dropping property coverages due to flamability characteristics of Spray Foam. You are adding an Accelerant to the structure.. in case there is a fire. How about using Reflectix double sided bubble, radiant barrier instead??

[@kennedyadams7159]

We see little difference between the performance of single and double bubble wrap insulation. The latter simply has a second layer of air bubbles (A balloon with more air). Although we strongly recommend Prodex Total over either, if your budget doesn't allow you to purchase the quality of Prodex, we suggest you order single bubble insulation rather than a double bubble. You'll get virtually all the benefits of the double bubble while saving money. Because bubble insulation has a core composed of air rather than closed cell polyethylene foam, it lacks the long-term consistency in performance of Prodex Total Insulation. Foil only products are typically perforated and composed of two metalized surfaces with a mesh woven in for strength. It is not a vapor barrier, it has no R-value - It is not insulation per se. It's a thin layer of reflective low emissivity film installed with an airspace to block radiant heat transfer between a surface that radiates heat. We refer to these products as foil only radiant barriers. Unlike foil only products (no inner substance), Prodex Total protects against the energy transferred via conduction and convection. Prodex is a radiant barrier + insulation + Vapor Barrier. More than just a radiant barrier, Prodex Total is one solution for Heat, Cold, and Water. Prodex prevents condensation, heat from coming in and heat from getting out of your building! Foil Only Products Are Not Insulation

[@kennedyadams7159]

We see little difference between the performance of single and double bubble wrap insulation. The latter simply has a second layer of air bubbles (A balloon with more air). Although we strongly recommend Prodex Total over either, if your budget doesn't allow you to purchase the quality of Prodex, we suggest you order single bubble insulation rather than a double bubble. You'll get virtually all the benefits of the double bubble while saving money. Because bubble insulation has a core composed of air rather than closed cell polyethylene foam, it lacks the long-term consistency in performance of Prodex Total Insulation. Foil only products are typically perforated and composed of two metalized surfaces with a mesh woven in for strength. It is not a vapor barrier, it has no R-value - It is not insulation per se. It's a thin layer of reflective low emissivity film installed with an airspace to block radiant heat transfer between a surface that radiates heat. We refer to these products as foil only radiant barriers. Unlike foil only products (no inner substance), Prodex Total protects against the energy transferred via conduction and convection. Prodex is a radiant barrier + insulation + Vapor Barrier. More than just a radiant barrier, Prodex Total is one solution for Heat, Cold, and Water. Prodex prevents condensation, heat from coming in and heat from getting out of your building! Foil Only Products Are Not Insulation

[@charleyandsarah]

What about putting vapor barrier under your footings, and leave the footers, piers, stem wall, everything within the vapor envelope? Bring the vapor barrier up exterior foundation wall and shingle/seal the exterior sheathing to foundation vapor barrier

[@joeseabert8391]

I want to build in Florida in a couple years and I’m interested in your series, I’ve liked the idea of a crawl space because the home is off the ground and away from ground moisture.

[@deanslegos1990]

8:36 looks like a dream down there

[@masterbuiltdesigns6734]

Thank you for running this style of education class for us, I'm definitively gathering ideas for my next home build.

[@LuistheABF123]

They're good to hide your money in plastic bags, scream at your wife when she gives it away, and laugh like a madman while your phone rings.

[@MrBigmanhimself]

*WHERE IS THE MONEY!*

[@gilzr473]

Alberto2341 10k that's a great deal, someone had a similar problem, but this was caused by their own pluming system that got clogged up for Who knows how long, until a pipe bursted and started flooding the crawl space going all the way up through the floors in to the bedrooms, the quote they got was about $60 grand. Not a good situation.

[@isaaclim1104]

Gil Zr bruh

[@Jonathan-sf6ej]

breaking bad

[@User78813]

@@isaaclim1104 lmao

[@augustreil]

I insulated homes back in the late 80's on the shoreline of Ct. If you want to experience the shittiest crawl spaces in the U.S.A., come here. 16'' and under for the most part. There was no 16'' or 24'' o.c. those floor joists were all over the place. You literally had to drag the batts over your face while laying on mice infested talcum powder dirt floors. I think the pay rate was around 6.50hr ? Don't miss them days, that's for sure ! Cool video Matt !

[@gfriedman99]

august thanks. That actually makes me feel better about my short basement. Im in ct on the shore fortunately its 4 feet down there. Still a pain in the ass to manuver around on bad knees.

[@NelloCambelli]

Slabs are terrible in Houston's gumbo soil. Your concrete floor idea is very interesting. Here in CA I am building a full basement/garage.

[@OrionsKelt]

Most places in the south you can’t spray the foam all the way up to the joist you have to leave a gap, usually about 6 inches, for termite inspection.

[@21gonza21]

No termite gap when you sprayed closed cell foam?

[@ericmcquisten]

No... not if its done correctly... termites, moisture, air, etc... closed-cell foam takes care of it all... but it is spendy.

[@bearded4glory809]

How are you conditioning the space? Do you put a HVAC register under there? Here in California we are allowed 3 options in the Residential Code: 1. Continuously operated mechanical exhaust ventilation with a transfer grill to the interior of the house 2. Conditioned air supply in the crawl space with a transfer grill to the interior of the house 3. Using the crawl space as a plenum for the HVAC to run through 3 isn't an option so it is either 1 or 2. Either your pressurize the crawlspace and allow it to bleed into the interior or you pull a vacuum and hope you suck air through the transfer grill like you were intending instead of sucking in outside air. Maybe option 1 is the best and we can probably use that exhaust as our whole house ventilation as long as it meets those requirements but seems like a way to introduce dust and dirt into the crawlspace.

[@eideticex]

#1 is a pretty nice option. Depending on what regulations are like and what size of vent you have available. You may be able to build a venturi so that whenever the blower for the home kicks on it drags air from under the house out with the exhaust. Seen it done on a couple houses and while they were still dirty at least the crawl spaces were dry and much more tolerable smell than mold or rotting wood. #3 sounds like death. Gotta remember there are some fairly dangerous gasses that rise out the soil. Even with proper barriers in place, your then adding more heat to the crawlspace than is already present. I don't know if you ever entered a crawlspace during winter in a cold area where it's miserably hot because the vents and floors aren't insulated. While it's nice for keeping the pipes thawed, I would not intentionally induce that situation and thermal wrap for the pipes is way cheaper in the long run.

[@bearded4glory809]

I ended up specing #2. I figured this was the best solution because the crawl space is quite broken up and this will make sure all areas receive airflow. I also included dehumidifiers just incase. I think #2 is probably better than #1 since I would rather have the crawl pressurized rather than in a vacuum to prevent any unsealed areas from pulling in dirt/debris.

[@jonathanparton6779]

You said “I will show you bad crawl spaces and show you how to fix them” you advertised for yourself and the company the whole video. Thanks for the help 👍

[@CharlesWilson-zs3vd]

Totally agree.

[@markproulx1472]

This is all well and good, but of little help to those of us who own homes with bad crawl spaces. If I were to build new, it’d be a different story. As it is, I watch stuff like this and just get depressed

[@tedrowland7800]

Mark, There are ways to make crawl spaces better. In MI, we often slide in I-beams and raise the house up and add block. I am going to build a new house on a crawl. It will be 4 blocks high, (32 inches) and after all underground is installed, I will pour a 3" slab. Firing strips will run across all joists at 2 ft. o.c., and install R-38. My furnace / a.c, and hot water on demand will be in the attic. All water supply will come from overhead. All will be heat taped, insulated, and set into the fiberglass R-38. I am retired, but jacking up houses here is very common practice. Many basements were 6-6 and 7' tall. They lift them and add block to make 8 ft. basements.

[@barbarasmith6005]

I am living in a house now with a vented crawlspace (1956 house). I'm pretty sure it is or soon will be, a squirrel nursery.

[@bobbyt9431]

Looking at the same thing with my grandma's cheap old rental with a vented crawl space. The house isn't worth enough to upgrade the crawl space, so I think the best option is to seal the vents in the winter and open them in the summer.

[@matejsramek3195]

I have no idea how I got here, but thanks youtube reccomendation, I will consume this content

[@joijoi617]

Thank you for your honesty!❤😂

[@bestbuilder1st]

Posted Earlier: Most builders would like to build using the products and techniques Matt uses, but they can't because "modest" homeowners CAN"T AFFORD or are unwilling to pay for these products or techniques. If Matt had to build a "modest" home, he would have to build them the same way other builders do, with crawl spaces and most the other stuff he says you shouldn't do. In the northwest, slab on grade usually isn't an affordable (insulations issues) or good option and high water tables make for expensive options or leaky basements, mold, and mildew It would be nice if everyone could drive a BMW/Mercedes, but like houses, most people drive regular cars and live in regular houses. If Matt made videos about high-end cars, most of you would be troubled by the "corner cutting" the "modest" car companies do. But with cars, most people don't seem to care they are NOT driving the best, most technologically advanced car. Like most things, technology flows downhill, and the regular houses of the future will be built like the super houses of today, much like accessories that were in high-end cars of the 90's, are standard equipment in today's cars. Great products of today will be standard stuff in 10-20 years. Unless they find out that the high-end stuff is causing other unforeseen problems like stuff in years past (think LP and others). I think you get the idea- I could write a book about this whole issue. Matt, keep up the good work and don't let anything I've said slow you down. I appreciate all you are doing for the industry (and your pocketbook).

[@bguen1234]

Paying for a concrete floor in the crawl space is just absurd and wasteful. Otherwise though, insulated, sealed crawl spaces are absolutely necessary in most areas.

[@MadProphet_97]

I still think if you build a crawlspace, you should at least encapsulate it. Much cleaner and easier to maintain. Granted if you can't afford it, you do what you gotta do. But I think it's worth a little extra dough to go that extra mile.

[@sherischneider2672]

Great video. My thought is that when you finish your crawl space this well (and you should), you could just as well build a split level home. That gives you the best of both worlds.

[@gfriedman99]

Sheri Schneider how

[@6willis]

@@gfriedman99 it was a joke

[@Williamkwood]

When rehabing an existing crawlspace what would I do for the entrance? It is currently accessed through the outside. Should I try to build an airtight door out there or should I move the access point?

[@bengunderson712]

Try and work with local job sites and get that temp orange construction fence/webbing. Staple that to the crawlspace ceiling/joists and you won't have anymore insulation falling down

[@femineity]

Great information! So, what if you DONT live in a place where the climate is warm year round and you ARE retrofitting an existing vented crawl space? I saw where you showed, what I think was, a crawl space that was retrofitted with closed cell insulation that was sprayed up into the joist of the underflooring of the upper living space, but, if that was indeed a home located in a place that can get as cold as 15-20 degrees below in the winter, what's done to the flooring of the crawl space? If for instance that crawl space was graveled over, with vents around the perimeter, and was a split-level home where once you come out of the small crawl space door, you're then able to get up off your knees and stand erect into what is the basement laundry room area that has 8ft ceilings. What would be the best way to retrofit a crawl space like that? Would it be wise to lay rebar and have concrete piped through the vent opening on top of the gravel where there'd be a couple of people in the crawlspace waiting to float and level out the concrete? And if so, should the vents then be sealed off or left operational to vent during the warmer months? So to recap, if someone has a vented crawlspace in a split-level home that is in need of a retrofit upgrade, would it be a good idea to #1. Blow closed cell foam insulation into the joist of the living spaces above the underflooring? #2. Can/should the crawl space be piped with a floor of concrete on top of the rebar? #3. And, once completed, should the vents be permanently sealed off or left open for venting during the summer months (is it still needed at that point?). And lastly, #4. Like in the example used of your friend's company's practice, should insulation and a wall moisture barrier product be attached to the walls as well? Or?! (I guess this would be #5) Would a crawl space that experiences winter temps as I described, scrap the concrete altogether and have the crawlspace encapsulated with the same sort of product in your visual example, covering the floor of the crawl space with a thick vapor barrier and the walls with rigid insulation? 😓😰😵🥴😵😕Talk about being confused! My house is so cold during the winter months and I'm close to selling just on the sheer amount of creepy crawlers that find themselves in my living spaces!!!!😨😩😩 Please help! I need advice really badly!

[@elijahleereeder6909]

Matt, I have a 20 mil vapor membrane in my crawlspace, but it is damaged and inconsistent. Instead of ripping it up, could I simply overlay a new membrane?

[@AudraGibson]

Can’t build a basement in Florida or South Carolina. It would be an indoor swimming pool due to the water table. Slab gives some advantages, but it’s a pain in the rear if you ever need to fix, move, or add plumbing.

[@TrumpsaTerroristChangeMyMind]

I’m looking for a home to live in right now and sooo many have crawl spaces and time after time they have foundation issues... I’m looking at a home from the 1920s right now that’s gorgeous it stayed it had a basement but the posting was wrong it has a crawl space and I’m worried to find foundation issues I’d feel so much safer buying a crawl space constructed the way I saw in this video

[@Blake919]

Matt... I’m in the Midwest, and currently have a vented crawl. Spray foam the deck and the walls?

[@benbalk8925]

I’m in northern California. I bought a home that was built in 1927 with a 18” crawl. There is no duct work as we used ductless mini splits. We also used pex piping for water. We did fiberglass insulate with the vapor barrier toward the subfloor. When in the crawl it was so dry it felt like concrete! So here’s my question... recently it rained and this home never had gutters prior to our remodel and now I smell musty air from time to time - assuming it’s coming up from the crawl - should I still seal the crawl or just redirect downspouts? Our humidity is below 70% most of the year. And our climate is typically 40-90 degrees most of the year. I currently have vents, but no fan - the access to the crawl is also basically a huge vent too- with lattice over it.... what solutions would you propose? The internet is full of salesman and really contradictory- help! I was to be safe and keep my family healthy!

[@david740819]

홈통과 팬이요

[@Ed1Ward]

Your information is invaluable. From an Australian.

[@madman432000]

Flood zones, flood vents, etc. Let water flow in without dislodging the house and let the water flow out when receding. How do conditioned crawl spaces work in flood zones? What issues will you encounter in the event of a flood? Not sure I want to tackle the work of pouring a slab under my 62 year old house. Maybe we should just build on stilts.

[@charlesjohnson8983]

We have a requirement in my area to build in flood vents how can I build a conditioned crawlspace and include flood vents

[@vadimnesen8060]

You build the vents by code than seal the vents after inspection

[@donaldwashington9017]

Thank you very much Matt very good segment on crawl spaces

[@gythan]

How do you fix a pre existing crawl space that is vented? We have just bought a 1954 timber frame house on posts with timber boards around the crawl space. Love the content, keep it up. From Australia.

[@chrislowe6278]

Glynn Jones you dont need to fix it. Having the open ventilated space will keep things nice and dry.

[@robsp32]

We have a vented crawl space in our home here in South Jersey, built in 1962, issue we have though is that the underside of the floor above which is our living room, is uninsulated, and neither is the duct work which runs through the crawl space including our air returns to the central air system. We have had to put damp rid in there for years because it tends to give a musty smell for whatever reason and I am just so unsure as to what to do about it. Obviously insulation between the crawl and the floor above would improve the homes R value but I don't know if that is proper and would cause wood rot.

[@rabbycacker]

@@robsp32 Watch this video again, he is right on with his assessment of crawl spaces. Clean, neat, sealed, conditioned, and well lit. I've been in many hundreds over the last 40+ years so have a pretty good idea of what is going on with them at least in this area of Alaska. Every type from muddy belly slithers you can hardly fit thru to fully decked out play rooms with with carpet and double padding underneath. One of my customers had a full blown HO train set with switching station and controlled lighting so the trains could run off into the darkness and all you could see was the lights of the train, street crossings, and a town in the far distance etc. That was way cool but took time to work around. Do the math on the foundation wall, always less square footage than the floor area above. Spray foam is the best but most expensive altho you can burn up a lot of labor installing sheet goods and end result will probably not be as tight as spray foam. Spray covers 100% and seals all of the nooks, crannies, gaps, cracks and holes. The better it is sealed the less air infiltration / heat loss there will be. In addition there will be fewer places for mice & bugs to hide, breed and travel. There is a foam ground pad available that will provide insulation and vapor barrier but should be laid on a smooth graded surface such as sand to protect the integrity of the barrier. I have only seen the foam ground pad a couple of times, usually in this area we see 6 mil poly visquene on the ground. Sometimes none at all but usually poorly installed with large voids and a musty smell in the space. Later homes with an Energy Rating will have taped or Tremco sealed seams and fiberglass batts stapled or Simplex nailed to the mud sill on the blocks. The floor is left uninsulated unless staple up radiant is installed. Radiated heat from the ducting or hydronic piping keeps the space warm to protect the piping from freezing and keep the floor warm. Some codes allow a fully conditioned space to be heated with the central forced air heat system supply and return air duct openings into the crawl space The concrete floor is nice but not required and usually out of budget. One of my customers did his place that way and bragged about how nice it was. Nice idea but the end result was the surface was so rough a creeper would not roll and it was actually worse to work in than a lot of gravel floored crawls. A really big mistake I see all of the time is non treated lumber used for skirting and installed in direct cotact with the concrete. Other building debris and wood scraps left on uncovered ground or under a loose fitting vapor barrier is another problem. These items deteriorate from the moisture picked up from the ground and provide an environment for molds to grow. For my 2 cents worth a heated properly conditioned crawlspace in a cold climate is much more desirable than an insulated floor. Think of the upstairs floor in a 2 story house, the floor is comfortable from the heat of the floor below. With an insulated floor that is not radiant heated the insulation holds the the cold and the floor feels cooler as it is difficult to get the heat from any source to go down. At least that is what I have observed over the years.

[@PapaSmurf337]

Closed Cell foam insulation is extremely sensitive to moisture - during installation. You can't just go down in your crawl space and start spraying foam everywhere, all surfaces that are going to be sprayed have to be dry otherwise you're not going to get long lasting adhesion

[@RoRo-ej2kc]

Foam is terrible! No idea what he's on about!

[@jeffreykershner440]

How do you handle Radon buildup in a sealed crawlspace? Also, if a pipe leaks in there, where does the water go? I'm in the PNW and we have multiple sump pumps in the crawlspace during the rains the water table comes up to about an inch below soil level, how long until it finds a way around the slab and then can't escape easily?

[@MadProphet_97]

If you live in an area with Radon, you can actually purchase a vapor barrier that doubles as radon protection. If the pipe leak is small, it will pool up on the vapor barrier and it's a simple shop vac. If it's a pipe freeze, and floods the entire crawlspace, more than likely the water will penetrate through the seams, even if it is taped. May require a removal and replacement of the vapor barrier, on the insurance company's dime of course. Sump pumps are only necessary in certain areas, and I have never seen them used in a crawlspace, only in basements. Having a sump pump in a crawlspace is begging for the pump to fail and to have it flood, probably without the homeowner knowing. Then you will have a ridiculous amount of mold growth on the joists, and spend a fortune on remediation unless insurance covers it, which they usually don't.

[@jpbiscaro8694]

Hey Matt would you ever do an episode on showers or tile in general? Maybe even heated floors?

[@devinm3618]

Here in Canada we make our crawl spaces insulated sealed and conditioned.

[@sc1338]

devin m good job guy

[@axiomluxury12]

We do a lot of these and always run into issues at the building department. If we call them a mini basement they are OK with it. We also run a 110cfm fan down there for air exchange

[@gfriedman99]

Axiom Luxury Mini basement. Its not a crawl space its a mini basement!! LMFAO.

[@Maythebridgesiburnlightmyway.]

Shooting my shot on a reply. I have a 115 year old home in South Dakota. Our basement is cement BUT I can see our old crawlspace stones and I’m trying to figure out how to encapsulate that! We were quoted 20k to not even fix the problem of water coming in from those areas. I really want to do it ourselves because it’s not even doing anything to the old crawl space and just the cement walls that were built and that’s just silly for that price. Will close cell foam (spelling?) work for sealing the old stone space?

[@ctbt1832]

It would be good if you had video showing exactly how you do it especially with the vapor barrier because I’m wondering do you have a concrete slab or do you have stone under the vapor barrier