I’m recommending we NOT INSULATE This Old House

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[@aarontpassmore]

You’re missing the most relevant factor as to why those walls are dry on the inside: lime mortar. The bricks are laid with lime mortar, which is less dense than the bricks and breaths/allows the moisture to wick out on a grand scale and evaporate.

[@kevinhibbard320]

Idk if you're right, but it sounds good. You get a like haha

[@Rumpelstiltskennedy]

Yep and lime plaster on the interior, which they just ripped out--ooops

[@evenstevens280]

@@kevinhibbard320 They're 100% correct. This is how solid walled houses are pointed in the UK, and if they're also rendered they're rendered with lime. Houses of this period that are pointed or rendered with cement often have so many issues with blowout and damp

[@carlsapartments8931]

I use lemon mortar... I save lime for my ice cold Corona

[@SeekingTheLoveThatGodMeans7648]

@@carlsapartments8931 Grapefruit plaster is also good.

[@MyLolo51]

The author does like to from scratch, kzbin.infoUgkxbnOKZBE4evMO5V2vroHeCjq6d_MV6wJO shaping and trimming wood from large blocks into fine finished products. As another reviewer mentioned, most projects require a lot of high-dollar equipment that most of us don’t have the room or budget for. But, knowing how to do these things, even if we won’t be able to practise the full stack project, is still great.

[@Mulberrysmile]

I lived in an old home in Spain. No insulation, concrete and stucco build, plaster walls. It got cold and I turned on my kerosene space heater, closed the door to that part of the house and started fixing dinner. You cannot imagine my shock when I went back into the living room to discover I couldn’t see farther than my arm! The extreme moisture held in the walls formed a thick fog cloud inside the house with the introduction of the heater. ☁️☁️☁️☁️☁️ I opened the windows as the air outside was drier than inside.

[@alafrosty]

I believe you. And that's hilarious!

[@foogod4237]

You should always have the windows cracked a little when using a kerosene heater indoors anyway. Otherwise their combustion products (CO2, carbon monoxide, nitrogen dioxide, etc) will accumulate in the room to unhealthy levels. You should also only use them as much as necessary, and turn them off every so often and air out the room before continuing, if you're doing it for a long time. (It is ironic that in places where these heaters are your main heat source for a home, to heat up your home in the winter, you actually need to open a window...)

[@Mulberrysmile]

@@foogod4237 The room had ventilation via a fireplace, but you aren’t wrong! Good advice!

[@nofurtherwest3474]

Pics or it didn’t happen

[@Mulberrysmile]

@@nofurtherwest3474 I took three but something went wrong…the film printed out nothing but whiteout. 🤣 joking

[@hbb3367]

Not a contractor, and really a only small project DIY guy, but I never miss one of your vids. Thanks dude!

[@Naiemaa]

I’m not even in the game anymore used to be a handyman and help carpenters but still love learning from his videos!

[@TheHudakattack]

my professional opinion is pack those stud bays with moist soil from the lawn, set up a sprinkler to keep them wet for 48 hours, staple some poly over it, and drywall it in, but then again my profession has nothing to do with home construction

[@mikeoland5909]

than the question might be why are you giving some professional advice on something, when you stated that's not in your (professional) area. WIERD

[@JoshuaMothis]

@@mikeoland5909 not gonna lie, your pretty weird, he obviously was just making some random stuff up and messing around lol

[@barndancer6149]

@@mikeoland5909 it's funny how people without a subtle sense of humor don't understand subtle humor. WEIRD.

[@joseochoa7043]

My house is from the 60’s all the exterior walls are solid masonry. This is EXACTLY the idea I had to make my home more comfortable.. One room is significantly colder because three of the walls are solid masonry. Any help would be appreciated

[@DandelionPink672]

But I should plaster the garden walls, right?

[@james.telfer]

Solid brick wall construction is how all Victorian era houses were made, just like a large percentage of UK houses. You might get mold on cold walls in near freezing wintertime but nothing rots as it's all breathing. Even the floor joists are all intact. You can of course insulate with Rockwool, as I will be doing to my house because solid walls are bloody freezing in winter. 🥶

[@TheRozylass]

I beg to differ--Our 1898 Queen Anne is not brick, it's sided with wood, interior is lath and plaster.

[@DanielZajic]

Not where I live (northern NH). It's almost unheard of to see any brick, except the tops of some foundations. My 1893 is all wood exterior, lathe and plaster inside.

[@fabriglas]

Fellow uk resident who bought a solid block home... how are you going to manage the moisture build up or prevent it?

[@westelaudio943]

Wood frame with brick veneer just like this (though usually less cheapish) was already very common in the outgoing 19th century (in the Us).

[@pauld3327]

​@@fabriglasYou could use wet-sprayed cellulose

[@dee73]

I think what everybody missed on this home is that it is balloon framed the wall studs go all the way to the foundation it's constantly circulating air all the way around the outer shell from the crawl space I think this house could be insulated within baffles in the wall to keep the air flow circulating it'd be perfectly fine for another hundred years

[@jimp5024]

Exactly my thoughts.

[@barefootinsylvan]

I hear what you're saying, and I agree, and I think that can work in the final whole home system, however...I'm in Canada, colder climate... can't think of not insulating the house. IMO, poly inside the framing and seal it, and then build an inner frame with modern insulation technologies, likely something that breathes well such as rock-wool. You lose a small percentage of overall square footage, but with a house that size nobody will miss it. The outer wall still moves any moisture it needs to, the inner wall is protected from that, and the house enjoys a proper insulating layer. Matt, thoughts?

[@AdamSJarrett]

I was wondering the same thing and this is the question I am dealing with in my house as well. The one issue I see is my house has 2x4 studs so adding baffles and then insulation, I would need some kind of very thin Rockwool which I'm not sure they make. Not to mention all the other stuff like electrical I need to run through my walls.

[@pcatful]

Are you thinking baffles on the outside of the cavity?. In cooler climates I'd wonder if you are placing the dew point (for in-house moisture) inside the wall. Yet what you are describing is a little how a vented attic works.

[@dee73]

@@pcatful yes sir

[@HobbyOrganist]

Unfortunately the brick has an R value of about ZERO, my former boss in NW Iowa restored an 1898 2 floors and attic all brick, slate roof townhouse, I remember he said his utility bill was $800 a month on average- he was basically heating and cooling the SKY with that zero R value brick and single pane windows everywhere. Without insulation you are going to pay thru the nose for heating and cooling, and it will never be comfortable when it's 20 below zero and windy outside, especially with single pane windows!

[@DScott-sx2iw]

I'm not a pro, but I'm having a tough time wrapping my head around particle-board in the 1920's... seems off to me. But the content of this video is spot-on. I wonder - is there a way to vent a wall cavity like you would a roof or cathedral ceiling? Maybe then you could get some insulation in there behind a double wall or something?

[@danbiss87]

Everything was balloon framed back then and vented through the attic. They are going to mess up if they put fire blocking as required by code. Its always best to apply the same building techniques used because they were constructed with full knowledge of that system at the time.

[@sunshinecompany1]

@@danbiss87 thanks...so I shouldn't put 1x4's between framing?... To slow fire spread? 🤔 and HOW can I insulate from inside? Can I use fiberglass and poly then drywall? I need heat without destroying 150 yr farmhouse. 😄

[@lifeinchicago9112]

This is a great video. I see so many people trying to remodel old homes in the north 100+ years and trying to go net zero at the same time and you see problems almost immediately sometimes.

[@sunshinecompany1]

So how do I insulate a 150 yr house from inside?? No videos seem to cover that anywhere.

[@lifeinchicago9112]

@@sunshinecompany1 usually people gut the interior and install fiberglass batts or punch a bunch of holes and blow in cellulose or fiberglass

[@sunshinecompany1]

@@lifeinchicago9112 some I had to gut and was gonna do fiberglass and poly but some are saying not to so I'm confused more now. I's poly ok on top fiberglass inside balloon framing? 😐

[@lifeinchicago9112]

@@sunshinecompany1 if you dont want to gut you can blow in your attic ideally is easiest (just make sure the plaster is strong enough to hold it). And you can pop a million 1" holes at the top of each joist cavity inside and blow in insulation. Not sure if you need poly, we don't do it in Chicago but I know some climates do

[@vapeurdepisse]

@@lifeinchicago9112 i don't get it, if you add batt insulation, you're asking for moisture trouble since there will no longer be air movement to dry the walls.

[@Frendh]

I would still insulate. There are organic alternatives that hold moisture. We use it for old farm houses. I would be more worried about vapour barriers than insulation. Matt did not explain it but here is what I believe may happen. If you put in insulation less heat will leech out to the old particle board. Which means moisture in the air will condense into liquid water droplets earlier because the relative humidity will hit 100% faster in cool air vs warm air. Which is bad. But if you add more material that can hold humidity to "share" the load of the particle board it may not be a problem. May not, as in if you do not do a good job it will probably fail. I would want the moisture to be able to move in and out so I would not put in a vapour barrier. You can always add more ventilation. I really recommend a vapour barrier if the walls are unable to hold a _lot_ of moisture.

[@toldt]

Matt, consider using fiberglass faced gypsum... They use it as sheathing on the outside of commercial buildings!

[@mikehermesmeglio]

DensGlass

[@toldt]

@@mikehermesmeglio yes, and DensArmor from GP. USG and others make similar products. I think commonly used on interior walls of commercial buildings before dry-in. I put it on the walls of my bathrooms and in the basement.

[@cemprotecta]

Thanks for the nice video. Well, following the same rationale, you can use natural insulation materials with hygroscopic properties like the ones used in building biology and also lime plaster with the same properties as well.

[@fighterpimp]

You don't have to use basic insulation. You can use other spray types that don't absorb water. That seems to be what he is afraid. So to answer your question. Yes!!!!!!!!!!!!!! 10000000000000000000000000000000% insulate that house.

[@omvaren]

You should insulate with natural (sheep)wool. Just like the other materials in your wall, it absorbs moisture and give it back in dryer times. No moisture barrier please.

[@rubbersole79]

Old houses that breathe are more healthy than the ballons we build now days in my opinion.

[@yeltsin6817]

2 things. I think that particle board sheathing was called Temp test? At least here in Canada. As well I have found the bricks from the old days were a lot more “solid” and not as airy as the newer bricks. Maybe that also helps with the water penetration? Love your channel

[@thomaslinzey7496]

A good approach is using a heritage consultant as you say. Maintaining a breathable envelope through vapour permeable materials such as lime plaster is key in historic buildings.

[@Richie_7777]

Matt, could you do video on protecting homes against hurricane force winds. I really enjoyed your video about roofing, a lot of great information.

[@somedude-lc5dy]

the ultimate is concrete block, minimal overhang, lots of hurricane ties, metal roofing with frequent fasteners. ohh, and no big trees within falling distance.

[@angelacarter6593]

I appreciate the videos on making decisions with older homes. Thanks

[@AmenMama-qe4sq]

Why oh why are we not building with these antiquated materials and techniques today??? I have a 100 yr old house in a historic district. Built like a tank. Strong and solid. Wonderfully insulated. The walls are literally a foot thick with brick and stucco, which is masonry. I just do not understand our cheap materials and techniques today. I think it’s so incredibly sad.

[@OfftoShambala]

Lack of cheap labor?

[@classifiedinformation6353]

I'm an old house owner and have been restoring it(not renovating it). Thanks for respecting the old technology. In this case, sealing the house to make it a "modern" house would be a mistake. You have just gained my respect Matt. John in Bethel, Missouri

[@davidhorsley1149]

In the comments I read everyone including Matt has overlooked one factor, the brick. Granted, really old brick will absorb and conduct a lot of moisture, but that was because of how it is made. I live in an area where we have a lot of old homes (Colonial), where the bricks were made and fired on site. In many of these homes the brick are soft and porus

[@dafinoiu1]

Matt what about using SkamoWall Calcium Silicate Board in the interior...directly on the brick wall, I think this insulation solution will fit best for this

[@Somewhere-In-Canada]

That old sheathing was called Donnacona Board here and used vice drywall sheathing on the interior with wood sheathing on the exterior. Plus rock wool insulation stuffed in but had settled over the years in the 1950s post war mini house I gutted over the past few years here in New Brunswick Canada whilst cautiously wearing my P100/P3 mask lol. Personally, a lot of these old houses should just be torn down, recycled somewhat, and be rebuilt to a net zero standard. The bandage approach isn't going to work and it means a whole lot of tearing down and rebuilding which will cost more but less than what it will cost if not done in the long run.

[@randomrazr]

arent old homes built better though? not as efficient but if they lasted 100 years////

[@Somewhere-In-Canada]

@@randomrazr Agreed 100%. I live in one of the original homes built in 1823 near Hartland NB and added to over the years and its still standing but built way beyond the structural minimum codes that exist today. It has its issues that I'm working away at sorting. Of note it has an exterior framed wall and separate interior framed wall separated by about 6 inches sitting on the rock foundation. One day I'll fill that cavity with some blown in insulation and it'll be more insulated than the modern homes. But right now it takes about 6 to 8 cords of wood to heat in the winter

[@jessewood3999]

Yeah I'm curious what would happen if you used mineral wool throughout with it's high perm rating

[@michaelvictory7683]

@MattRisinger , We discovered NO SHEATHING on my remodel. Just studs with pink batts and then leaky brick. Surprisingly there was no mold, probably because the ventilation was so good. With the remodel I want a tight envelope without destroying the brick wall facade. I don't know what to do!

[@johnseavey6622]

It is what we called insulation board, was used on the interior before sheetrock or what was called homosote which was used on the exterior and painted in some cases.

[@jsnthurst1]

I would insulate with rock wool insulation that has no plastic or paper backing or facing to block vapor. The vapor will travel through the rock wool without condensing.

[@kenfenske5002]

I think that wall material is homasote fiberboard. Super-thick solid cardboard. It's made a lot like paper is made but blown into a sheet without water.

[@kevinchastain727]

My question would be is this wall cavity open from crawl space of the house to the attic, because if it is then that would be why the wall cavity is not rotted. The air flow through the wall cavity would have removed any moisture that would have gotten into the house.

[@hollynorris957]

I’m restoring my 120+ year old balloon frame house and we removed all the tongue and groove and insulated the almost 4inch stud depth by first a layer of 1/2 inch continuous foam board precisely cut to push in each cavity then sealing all edges with silicone caulk. We then used r13 glass batts for a total of 16.5 r value. We planned to then Sheetrock and ultimately ad lots of wood wainscoting etc using the t&g we took out. The exterior is clapboard witch was at one point covered with vinyl siding witch we are removing leaving the original clapboard. After this thought provoking excellent video I’m now thinking I should add a layer of some type of mesh over the clapboard before covering with 1/2 inch foam board and ultimately 4x8 sheets of smart panel ? We plan to close the space from the floor to the sill with rock wool to deter mice/ bugs. Any thoughts to help us… anybody ?

[@rtel123]

That sheathing is not new to me. In the Pac NW, many new stucco houses in the 1970s and 1980s used it, because of its better insulating qualities compared to plywood or shiplap, as well as low cost. Covered with tar paper outside. Then they would nail wire base for stucco onto only the studs. They did understand that it does not provide diagonal bracing like wood, so it was required to put diagonal studs into many cavities instead. Fortunately, the code already required continuous plastic vapor barrier before the sheetrock.

[@jaycos5978]

I have been renovating my 1926 balloon frame brick veneer exterior home. I insulated with Rockwool as my exterior sheathing had 30# felt WRB on the exterior side. I love old homes.

[@rauljaimes6739]

Did you add a vapor barrier by a chance

[@GeneralChangFromDanang]

Gotta love old houses. Dry walls but field stone basement that looks like a swimming pool.

[@bret9741]

It dries to the outside. Closed cell foam on the inside would not create an issue. It would allow the partical board to dry toward the air gap. I’ve been remodeling 1880’s-1930’s in Cleveland using closed cell foam for many many years.

[@markgarland9000]

"Particle board" looks more like hardboard. Different composition, different binders/resins. Hardboard actually stands up pretty well to moisture.

[@rkn700]

That odd sheet material is often called "beaver board". It does not mold easily for some reason. I would suggest having that old insulation tested for asbestos. Plaster is definitely the way to go in a house like that. I prefer plaster if the budget supports it and you can fine a good plasterer, which is getting harder to do.

[@Sparky-ww5re]

For sure. Back in the 1920s many homes were very solidly built, because the folks usually built their own homes and would pass them down through the family, just like the farmhouse that's been in my family since 1881 built by my great- great-great-great grandparents. Aunt Sharon and Uncle Bill currently live in it. Their oldest daughter is set to inherit the house once they move to an old folks home or pass away.

[@kerrykerry5778]

Old carpenter here. IMHE that is not Homasote, which is the trade name for "beaver board". It is the wrong color and does not break like shown. I believe it's particle board. That said, it presents issues with Matt's theory that the house was originally sheathed in particle board, as WIKI claims the stuff was not in production, as a commonly available panel sheathing until a decade later. So, the build date, or something, is out of sync here. If it was a 1920s build, I would assume that the diagonal board sheathing shown is probably the original. From WW2 to the 70s, particle board came and went as a structural sheathing product. Plywood supply issues, and economics, I guess. I had a friend who watched a new build go in next to his house, in the 1970s. This new SFH was on top of a small hill, in farm country. The builder was famous for building very low cost crap. The framers covered most of the rafters with 1/2 particle board and wrapped up for the day. High winds came through and over the next few hours the sheathing was reduced to chunks blowing around the neighborhood, leaving a debris field like a tornado, and damaging neighbor's cars, with bits of it still nailed to the roof. The mobile home industry gave it a try also. I have seen it develop huge sags between trusses, and create a bizarre looking shingled roof.

[@jongeers1954]

@@kerrykerry5778 The stuff he's showing is definitely not Homasote. I believe it is Beaver Board (which actually is its own trademarked name) or similar. en.wikipedia.org/wiki/Beaverboard The attic and part of the sleeping porch of my 1913 house are finished with it.

[@kerrykerry5778]

@@jongeers1954 Eh, true, but. Homasote sheathing was called "beaver board" for at least 75 years after the brand name failed. Both of these, and similar products that were popular until the 80s, were compressed wood fiber sheets. The product shown in the video is neither the same color nor does it break down by hand in that manner. I remember framing in the 70s, as a young kid, when walls were sheathed with 1/2" fir ply on the corners, and 1/2" black homasote sheathing for the field. At that time it was called beaver board by the carpenters, roughly half a century after the brand name failed.

[@keithhoffman22]

Why not use loose sheep's wool to increase hygroscopic buffering?

[@SgtJohnRemairez]

My parents bought a house that was built around early 1900s, they bought it cheap during the market crash around 2010. It's a brick house, and the people prior to us did work to the house, and we couldn't really see under the walls but some parts of the house just feel so drafty. I hate how it feels like I'm wasting alot on my energy bill and I wonder if it has something to do with the attic not being insulated because sometimes it feels like the same ambient temperature as the outside up there.

[@stevemullen8457]

That's insulation board, very common in old houses in the east. You'll also find it on inside walls at times.

[@pdavis2207]

I would consider spray foam in all cavities and sealing the bricks to reduce water penetration. Modern AC already changes the humidity balance of the home. With such a large home you would be wasting a lot of energy air conditioning the home with no insulation.

[@bigdaddyyc]

Spray foam would act as a vapor barrier. The particle board sheathing would not be able to dry to the inside of the home like it used to, increasing the risk that it would mold/rot.

[@YTPartyTonight]

I didn't even know they made that board material so long ago. I would have guessed they started making that material in the early '40s.

[@jps5144]

That board Matt is holding looks like fiberboard that Celotex used to make. It's made from ground wood fiber and run on a press with water, much like paper. Celotex was making it at least until the early 80's. Celotex also made an asphalt-infused fiberboard they called Sturdybrace for use as corner bracing.

[@borsistephen]

Easy way to fix the bottom mold issue is to puncture drain holes into the brick at the bottom where none can see them. In my experience things can get wet and dry out with no issues, it's when they stay wet that it's an issue

[@markpashia7067]

Bricklayers use to leave "weep holes" in the mortar. Usually the bottom course of bricks and they did it by leaving out the mortar in between the bricks on that course every eight feet or so. At least in St. Louis area. Too often the walls were tuck pointed much later by people who plugged them up and caused more trouble than help.

[@Sailor376also]

It is called Homasote. Not garbage. Moisture permeable. Fibrous exterior sheathing prior to foam sheathing. You use foam sheathing. No different except do you see any rot on the outside of those 2X4 wall studs? In and air conditioning climate?

[@motoman869]

Walls dont just dry from outside in but inside out. A vapor barrier could do damage. If you are up higher its less prone to mold. Lower to the ground the higher the moisture content. Doing vapor barrier in and around your foundation works wonders too.

[@1977jmad]

I have a 1929 craftsman style bungalow that has 3/4 inch shiplap inside and outside all the walls. I am renovating my home and decided not to wrap or insulate the walls because it is supposed to breath and dry out if water gets in.

[@DanielZajic]

I bet that house is beautiful. Wouldn't it work to use unfaced insulation and an air barrier that allows drying to the outside? Or would that still slow the drying too much?

[@jb_90265]

i have been debating the same thing with my house .. but i have plaster insides with clapboard outside . i'm thinking ZIP-rR on the outside (or plywood with atlas foam sheets ) with hardie siding with an air gap and no wall insulation ...

[@ericmueller4801]

Have an old home from 1920s. I have the ship lap sheathing seen here with balloon framing, no insulation. The wall material i tore off on 2nd floor exterior was Cellotex Lath (cane fiber board with 2 plaster coatings). I am wanting to insulate. Would you recommend the rockwool/thermafiber or a faced/unfaced fiberglass?

[@jeremyking3986]

I have an old farmhouse with just 12” brick exterior walls. Previously they glued paneling over the interior brick. I want to frame the inside to run electric and insulate. Then drywall. I just don’t know what insulation to use. The house is in Tennessee and was never insulated before.

[@lounar482]

Moisture vapor is a tough adversary and understanding how to combat it tougher still.

[@kousakasan7882]

I had a black spot appear on my kitchen ceiling, below the master bath shower. Pulled the sheetrock and found a leaking copper 90 degree. It looks like it had a slow leak for 20 years. Even though the screws had big rust circles around them, none of the studs had mold. Even though everything was soaked.

[@TroyAtLightNGames]

Could you use some kind of wool fiber insulation to stabilize the temps, but also continue wicking away the moisture?

[@urchin11]

As some have mentioned, adding air conditioning will change thing going forward, with or without insulation. Maybe you should consult some building scientists, before making a recommendation. It's very likely they will have tried renovations both ways before and can offer some insight.

[@dahveed284]

I agree that insulating that space can lead to a failure. A building that stands for nearly 100 years destroyed by the modern building code. Anyway, good luck getting the city of Fort Worth to approve that. They made me insulate my 1927 vintage home when I redid the kitchen.

[@DeDraconis]

What are some alternatives to modern drywall in general? I rarely see places with anything other than drywall or paneling.

[@GlenS123]

Excellent conversation to have!

[@martintroup8100]

If the owner wants to use sheet rock instead of plaster job, it is wise to prime the back of sheet rock with "Kills" primer paint before enclosing the wall cavity. Also , instead of insulation. Maybe press into the cavity that tybeck fabric instead of insulation.

[@ModernNeandertal]

Very good information. Thanks.

[@DMJ160]

On my 130 yr old home, there is no sheeting on exterior walls. Just studs and you see the brick with plastered walls. Now, the house is covered with aluminum siding top to bottom. Wouldn't this make it safe to insulate the cavities? I have to assume no moisture is getting through the aluminum siding.

[@aayotechnology]

What's on the outside of the solidly sheathed wall? Sounds like it's not brick. I didn't catch it.

[@guylambrechts2303]

Hempcrete could be a solution to insulate and keep the ability to dry out.

[@pauld3327]

Agree.

[@loganperry1346]

Would it make sense to just spray foam all the cavities?? And maybe add a sheer board on the inside, that way even if there was significant water getting into the old particle board, it could just rot over time and have no effect on the house, since the spray foam is keeping any mold particles from entering the house and the new sheer board can take up any of the load from the failing particle board

[@imtheonevanhalen1557]

In NC, you start a remodel with a permit, it has to brought up to minimum energy code requirements.

[@davidmorrow4195]

Good point. If following the law and getting a permit you will have options for the type of insulation but not whether or not you do it.

[@bigdaddyyc]

Why not just add Rockwool with no vapor barrier? Rockwool is vapor permeable and shouldn't cause additional mold risk to the fiberboard section.

[@jsclipse]

Repairs to old houses should be undertaken like restoration of an antique cabinet. Don't modernize it - preserve it. There is no reason to change this into a 2021 new construction. Sure you can make it look pretty, but quality building materials and quality workmanship kept this house livable since the 1920's. Repair it with high quality materials, update the electrical wiring, install high quality windows. Don't make this an airtight submarine. With forethought and planning, this house could outlast us all.

[@JonDunnmusician]

Outstanding discussion- nerdy discussions trump mediocrity! Kudos 👏

[@tastyfishsauce4410]

Solid old growth wood probably has a lot to do with it resisting rot? I could be wrong.

[@timlyman4892]

That stuff looks like Celotex lath. It was used as a foundation for plaster, and would normally be found on the inside of the framing. Not sure what it's doing on the outside of the framing.

[@JoseRodriguez-pn9hx]

I have an old house, 1959 and i want to insulate the walls. And i want to replace siding as well. Do you think it would cause issues if i do that? Based on what was said on the video? Thanks for the feed back. I live in Texas and summers are a nightmare

[@jbrown2905]

Wood lath and plaster..,! Gypsum board, as manufactured in this present day , (in my 40 year experience as a GC engaged in residential work,) is the greatest liability and health threat of our industry. It’s a complete bait trap for the slightest intrusion of moisture to trigger mold, mildew, rot…. 😣😣. How and why do we continue to embrace this disastrous building product??

[@godbluffvdgg]

00:33 That stuff WAS NOT INSTALLED when the house was built...Obviously, someone did exterior work, most likely in the 60's-early 70's ...Come on Matt; it's not that hard...

[@thenexthobby]

I’d be curious to learn what decisions were made on this remodel. We learned from this video not to treat it as a modern design, but the conclusion to not insulate isn’t supported unless all you know about is modern design. As many commenters below have already and repeatedly said, there are ways to let the brick and sheathing breathe without requiring the interior of the envelope to breathe. Yes, it’s building science and construction and our host here is a bit out of his depth for some reason.

[@robertschill2686]

Damn! Was that 1930s "beaver board"?

[@CarlosRodriguez-bb8nn]

Hey Matt I don't know if you can help me out with a video review on hebel aac panels they been using them for two story houses here on mcallen tx and I was wondering how good are they. Thanks and Keep up the Good Work 👍

[@benjaminziegler7437]

What about using fiberglass matt drywall in place of paper face drywall and veneer plastering/level 5 finish?

[@guytech7310]

I'd probably go with rockwool since it does hold water. At best you might be able to get away with a thin amount of rockwool that has many R-4 so there is sufficient airflow to allow it to dry. Realistically the only way would be to build some mocks up of the wall with different levels of insulation and let it run for a year (all four seasons). This why you have some real data to make a low risk assessment.

[@jonathanzappala]

Well it costs twice as much a sheet as drywall, probably only comes in 5/8, and then you have extra plaster work on top.

[@benjaminziegler7437]

@@jonathanzappala No, it comes in 1/2 inch too. I'd imagine if it solves the mold issue then it pays for itself in terms of what you would have paid to rip everything out that failed due to mold. Also look at that house and look at the potential client. You think they care about spending some extra money on their finished walls?

[@jonathanzappala]

@@benjaminziegler7437 yeah your probably right

[@marekbuczynski411]

Question? I Know on this particular home you would not insulate from the outside, but what if this was a 100 year old siding home Should you add exterior insulation and then new siding.

[@guyb7005]

Spray Foam (closed cell) insulation or standard with vapour barrier don't seem to be an option for you? It may not be done properly, therefore a giant energy pig is fine with you. I would then focus on insulating the attic.

[@AndrewWade77]

Is there a barrier that blocks drafts but allows water to pass through? Like tar paper?

[@AndrewWade77]

I want to make my old house and garage more air tight but not stop the walls from drying in both directions

[@macthemec]

I’ve thought about this on old houses, i’d probably do rocksol in the cavities and tyvek instead of poly on the inside.

[@carlthornton3076]

Very good!.

[@Herfinnur]

What if you applied isocell airstop in between?

[@samfish6938]

no heating,lots of ar draghts keeps moisture away also lath annd plaster will not rot

[@cynthiashaw45]

The dry climate of Ft Worth isn’t the same as an area that gets much more rain and humidity.

[@DavidNiedbala]

Question, we have a room upstairs on our second floor that has exposed beams to the base of the roof. It is not insulated but I want to insulate it. We just had a metal roof put on over our asphalt shingles that were leaking. There is no ridge vent. The leak has now stopped and now I'm ready to move forward with insulating and finishing this room, any tips or tricks?

[@FixthisCD]

Use polyiso on the inside (air and vapor sealed) then densglass on the interior for plaster finish then provide air circulation (in the cavity) if framing allows. If not use rockwool since it would not be affected by vapor drive and use densglass (permeance >17) with plaster finish which would allow drying in both directions. ??????

[@raspberrynz86]

Frankly speaking, these paper boards seem okay and these is a gap between brick wall and paper boards. Since it is just a small area, it is easy to remove all paper boards, replace with glass fiber boards (Hardie Flex Sheet) by fixing and sealing them internally, and then put insulation. The depth is enough for R3 plus insulation.

[@mrrb2916]

what if you use a solid spay foam insulation??? better or still same problems

[@ZimZam131]

Wow, I had no idea rock wool has been around that long. People still talk about it like it’s the new thing.

[@rl5055]

hey Matt, how about sheetrock on the exterior attached to the framing?

[@itseveryday8600]

are cement board mold proof?

[@shoes121255]

Is there not an air gap between the brick and the sheathing like a modern build?

[@mikee1891]

To my eyes it looked like there is an air gap at 3:30 where Matt is able to poke a finger in a sheathing opening. -shrug-

[@The518sean]

Currently renovating a 1940s cape in Upstate NY same type of fiber board and no insulation. What do you recommend to insulate?

[@RagedContinuum]

did you ever find a solution?

[@The518sean]

@@RagedContinuum all the companies called recommended a mix of open and closed cell foam depending on the location within in the house to get a good r value and keep costs down. . House also had a radiant barrier under the siding and thin foam layer

[@patrickday4206]

It's a type of insulation board we use to call it a derogatory name. 😂

[@simonmcneilly55]

Mans casually throwing around 1940’s rockwool....... your lungs will never forgive you....

[@routtookc8064]

nevermind the insulation, bull those studs out of that archway !!

[@quintaofensiva1432]

Why wouldnt you use closed cell spray foam as insulation?

[@geoffreysahs7650]

My only concern here is that J-M insulation from that era often had asbestos fibers in it…tossing it around like that is a bad idea. Some of their rock wool did…maybe some didn’t…at this level of disturbance, I’d be covered up.

[@gregorsamsa1364]

Asbestos isn't really as dangerous as it's often made out to be. It takes a lot of exposure before it's likely to cause any problems

[@carlsapartments8931]

it's funny that they demolished the walls around the windows but the window coverings are still hanging... lol

[@happytomeetyou.3027]

Highly reasonable Matt, good work!