DIY: How to Install Under-Deck Roofing

Today we’ll be showing how we installed some polycarbonate roofing panels under our deck to make it water proof. The soffit ended up being very cost effective compared to getting a similar roof installed professionally. All the water gets collected and routed, keeping the patio underneath dry.
We actually built this project about a year and a half ago and despite the abuse of 2 harsh winters, the roofing has held up fine with zero leaks or need of maintenance.
Main Materials Used For Roofing:
• Pressure treated 2X4’s
• 1 ½” Hex-Head Roofing screws
• 3 ½” construction screws,
• Corrugated polycarbonate roofing panels
• Miter saw
• Circular saw
• Drill and driver
• Drill bits
• Nail-gun (optional but helpful)
• Large ladder
Extra Materials Used For Roofing:
• Gutter (vinyl is easier to cut and handle)
• Gutter straps
• End caps
• Downspout and outlet
• Glue for gutter
Music:
Track: The Perpetual Ticking of Time - Artificial.Music [Audio Library Release]
Music provided by Audio Library Plus
Watch: • The Perpetual Ticking ...
Free Download / Stream: alplus.io/Perpe...
This project is heavily inspired by a project from The Family Handyman:
www.familyhand...
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[@michaelsweat7951]

This is awesome! 2:15..."Your cuts don't have to be very accurate, but you should probably try to do better than this!!" And I mean it - perfectly presented and edited!

[@daveozsydney]

I liked that part - so rare to include mistakes in a how to video - makes it more real.

[@FijiLaw]

Was wanting to waterproof my deck but that would mean painting over the beautiful wood grains with some sort of ugly seal, your method saves me from doing that allowing me to stain and varnish the decking leaving it beautifull, many thanks!

[@danellsworth9922]

Awesome idea. Thanks for this.

[@sierraevans5329]

I’ve watched over 10 videos for this project and your video was the most clear, thorough, easy to understand video! Great job, and thank you!

[@DadandSonDIY]

Glad you found the video helpful! We put in a lot of effort to try making our videos clear.

[@rpols22]

Totally agree. I've watched a bunch myself and some of them were pretty complicated. This video was very easy to understand . The method and concept is very basic. Exactly what I was looking for. I will absolutely mimic this method for my deck this summer.

[@peacebewithyou911]

I agree. Literally 5 other videos before this skipped the one part I needed to see. Thank you for making it simple enough for me to understand.

[@eterno19001]

This is a very good explanation, how much you should be charge for this job.??? Any idea??

[@Ramcat_Vlogs]

The diagonal 2x4s I would of removed, added blocking between the joist every 4’ to keep the joist from twisting then you could of gotten the metal higher and made a cleaner look. But all in all well done 👍

[@bent7131]

This is really good. Perfect how-to video. Thank you. Have you had any issues with birds/critters building nests in the void between the the roof panels and the deck?

[@DadandSonDIY]

Not between the roof panel and deck but there were few birds that tried to build nest on top of the horizontal beam.

[@doug2078]

How's the Under-decking holding up ?

[@joeywadz5710]

Say you’re a DIYer without saying you’re a DIYer …lol

[@danglassphoto]

I used this same material and method under my decking and it did work for 12+ years before I had to tear it out. If you get a lot of tree debris on your deck that works its way through, it will eventually build up on top of the plastic and accumulate dirt and moisture. It did eventually start to bow and leak, but again I got 12 years out of it. I am now looking to improve on the material and installation, perhaps leaving some sort of port where I can hose out the area once a season, thus reducing the build up. Highly recommend a clean out method of some sort and you will get more years out of it.

[@thomasgruver5777]

I am just about to try this ... curious if you figured out a solution? we live in a very tree rich environment. With the corrugation, i'm afraid you'd need a lot of "ports" to be able to get to all the debris in each of the channels across a large underdeck. I guess you could just take it down every few years and clean it out .... but i'm looking at about 24 panels across... so that will be a pain. Love your thoughts.

[@docmag1983]

@@thomasgruver5777 If your deck boards are screwed down you could remove a couple at the upper end of the slope and use a hose to wash it off. Just an alternative.

[@jcatnip3556]

Did your "port" work? I am doing the same thing on a new deck.

[@WilliamAEscobar]

The inside backhouse should be more hight them theout side deck for panels so water can go down other wise the water will go back to house don’t make any sense.

[@Capdan365]

the panels will prohibit air circulation and cause the deck wood to rot eventually?!

[@BryanButler-q3q]

Next time you may want to do something other than send a screw into the "spacer" piece of 2x4 into end grain like that. Picture an axe splitting a piece of firewood. It splits along the grain. Those spacers will split along the grain where you've driven the screws (just like driving an axe into it) and leave them in 2 pieces, essentially unattached. There is really no structural integrity there, and that's what is holding everything up. Also there is limited screw holding power in end grain. Good luck.

[@captoblivious1]

This is exactly what i was looking for! thank you for the very detailed explanation, and the computer graphics were a nice touch. Very professional.

[@SinisterMD]

Curious, did you have any issues with water coming off the back (house side) of the corrugated plastic sheeting? I've been wanting to do something like this for some time because any water that drains through my deck goes into a drain that ultimately has to be pumped out by my sump. When it rains a lot it's a considerable amount of extra water for the pump to handle. Thanks.

[@schlenbea]

Thanks for the video - nice work! My favorite part: "you don't have to be super accurate but you should probably be more accurate than this!" It had me rolling😂😂

[@DadandSonDIY]

Glad you enjoyed the video!

[@carmelacimmino1056]

We have been looking for a solution to our patio staying dry for years, and this was it! Easy to follow and no leaks! Thanks Dad& Son

[@anjelinarosee]

This was a great video BUT!!make sure to check with your local fire department I did this for my house and the city and fire department made me take it down The plastic sheets are not up to code in my area I ended up using aluminum ones and they are great and up to fire code

[@heatherfrancis1482]

good to know! i just purchased aluminum only because the store only had the clear polycarbonate ones & I didn't want that look. will be attempting this roof this weekend - here's hoping I can make it work!!

[@moandaa]

Best line: "the cuts don't have to be very accurate, but they should be better than this"... as the bus tires roll over Dad. Definitely some unconventional handling of the circular saw by Dad. I assume he has solid dismemberment coverage. No safety glasses or dust mask and holds the saw guard open... nice! At least the old man put on some hearing protection part way through! I can empathize with Dad though.... I do everything trial and error style too. Why use the ugly panels? There are so much more attractive options. I'm going to use Pro-Rib panels from Menards. Again, I'm amazed that Dad is installing them all by himself. Maybe he doesn't let Son use power tools. Did I miss the dimensions of the deck? The width would be very helpful. It looks like 12 foot. I'm nervous about getting the purlin spacers right. Overall, solid video, but watch others for "pro" tips. Unfortunately, the thing is ugly and didn't have to be.

[@CoCoSWISS1]

The two of you make GREAT DIY videos. The Father/Son combo is heartwarming. Your voiceover work is fantastic. One word of caution. What happens if your father learns that you're adding the dialog later and you could be using a tripod and helping him hold up the panels, steady the ladder, hand him a bottle of cold water once in awhile and maybe even drive some screws? Just make sure he has disability insurance! Also, some people would find it useful for you to mention the tools you use and add an overview and a link, below. Maybe even info and a link to the materials. For instance: - Why is your drill making that rat-a-tat sound? Introduce the wonders of the drill-driver. - What is a nail gun? - What is special about the screws you're using? Do you screw into the part that is against the 2x4 (Purloin?) or to the part that stands off an inch from it? Most say the latter, which requires longer screws, but I'm no expert. The key to this added info, I think, is to just reference it below for further reading, but not drag everyone through the detail. You could also skip ahead or speed up repetitive steps, I think. The shorter the video, the more views you get. Just don't edit out things like your Dad almost falling off the ladder! Ryobi is a great brand for the DIYer. Maybe you could make more money by adding links to where the tools and materials can be bought. Just be very upfront about it, maybe offer alternatives, etc. YOU GO GUYS. You are very good at this!

[@chandana56]

Great job! This is exactly I was planning in doing. This video gave me the confidence. Thank you! One question I have is whether you need to predrill the polycarbonate sheets with slightly larger holes (larger than the diameter of the screw) to allow for any expansion?

[@paulplotkin304]

Great video. I am installing a variation. Question, do the long boards screwed into spacers block the water in any way? If the panels are screwed to the long boards flush, how does the water get through to the gutter system?

[@robcarter-e4p]

An "ok" effort. It pains me to see how sloppy this guy is. With a little effort, this could have been done with competency and pride.

[@matthewestes1662]

you didnt flash your ledger board, if you dump water right at the edge of your house/deck - water will drain down - hit your first purlin - and splash into your ledger board, under your siding and rot your wall - happened to me

[@SJS301]

How do you clean out dirt and debris which collects over time?

[@sandrajones798]

Have you been able to find a solution to the end where the water empties into the gutter, that the multiple wildlife into the space between the deck and the under deck. The deck is about 12 feet off the ground making it difficult to block the underside. raccoons, opossums, feral cat, chipmunks have all hid or hunted under there for mice, etc.

[@DadandSonDIY]

We set it up our gutter so the downspout just ends in a pebble patch where we have a drain. We haven't experienced any issues with wildlife getting between the deck and the panels, but a solution could be boarding up the sides :)

[@lesabeyta]

definitely a more cost effective way of completing the task. Not as polished as some of the commercial solutions, but effective. Thanks for sharing.

[@juansanchez5402]

I literally love these videos with all my heart. They bring me joy when I am in one of my deep depressions, and without them, I don’t know if I would still be here today (if you know what I mean). Thank you for creating these masterpieces, and if you ever stop, my life will lose all meaning. Enjoy your summer!

[@trampusschuck1019]

Very nice, I'm looking at doing this myself and your video is a help! Did you consider using flashing on the beam where the roof hits the gutter to protect the beam, or do you find there is not much extra moisture held on that beam?

[@DadandSonDIY]

putting flashing on the beam would no doubt keep excess moisture off of it. We aren't too concerned however because the beam is pressure treated wood and should last a long time.

[@TheDopalgangr]

Nice work, learn everything you can from your dad and enjoy your time with him. I learned a lot from mine and miss him every day. 😥

[@jcatnip3556]

How do you clean the leaves and dirt off the panels?

[@marvinobanana]

I would use PVC material for the spacers under the deck. It is more expensive than pressure treated wood, but it will not rot.

[@DadandSonDIY]

That's a good alternative. Thanks for the comment!

[@gagegr]

@@DadandSonDIY also, the spacers should have been screwed from the other direction, you don’t want to drill through endgrain. Just an FYI for those doing this now!

[@sonofphilip8229]

four years ago. I wonder what the cost was. I can't believe one single 2x8 panel of corrugated roofing cost $20+ at lowes.. I could see this project needed maybe 15 panels? That's over $300 bucks minimum right there. Isn't that the stuff homeless ppl make shanty towns out of??

[@timothyburtch5441]

Well done. Very descriptive. The CAD animation is great! Thank you.

[@ddharmoo]

Good video. Questions: 1. Can you explain the reason for putting the crossways 2x4? 2. What about the other part of the deck after the post? Meaning just below the railing. How will that area be sealed?

[@DadandSonDIY]

Hey, thanks for watching! I'll do my best to answer your questions. 1. I assume you are talking about the long 2x4s that we screwed into the spacer blocks. There were installed to have a mounting point for the panels. We couldn't screw into the joists of the deck because the panels need to be sloped to control rainwater. 2. You are right, that area was not sealed; though if you wanted to, sealing it would be the same process.

[@brucen6579]

Excellent video! Just about done with my job and following your steps all the way. Thank you, guys! You made what seemed to be a daunting job easy.

[@DadandSonDIY]

That's awesome Bruce! Glad the video was helpful!

[@geoffsanders4208]

Thanks for sharing. Any idea on how to clean it out? Worried if things begin to seep into it over time and do not flow out? Also, is there enough space for moisture to escape and not rot the wood?

[@DadandSonDIY]

We haven't had to clean it out yet but when we do, we plan on removing a couple of the upper deck boards and hosing it down. There is plenty of room for moisture so nothing should rot.

[@thedwightway1087]

Do you get airflow from the open sides?

[@davecollier8054]

Well done guys. Gonna copy ya!

[@samu3813]

Great work, great result. Functional and affordable!! One thing though, please be safer next time by not standing ontop of the ladder, so dad and son can enjoy each other a long time...plus your creation.

[@pritikamath5209]

Thanks for sharing wonderful video of diy project. Wondering what is the cost of the project? How big is the surface area ? And how long it took to complete the project?

[@DadandSonDIY]

Don't remember the exact costs or dimensions anymore. The project took 4-5 evenings to complete.

[@ebachy]

I did something similar, but mounted the gutter first. There was a 3/4" propane pipe along the house already, so I made sure the gutter on the oppose side was several inches lower. Then I built 1x2 ladder-like frames to bridge between the pipe and the gutter with metal pipe clamps on the ends that can 'hook' over the pipe and gutter. The ladders support each panel. I just laid the frames in place and laid the panels on top (no fasteners into frames through the PVC panels). The closure strips that match the panel curves help to keep the panels in place, but I do have to reset the endmost one after wind storms! They do overlap the neighbor panels. The panels and frames can be taken down to clean them, but I haven't bothered yet after several years here in the Puget Sound. We use a rain chain instead of a downspout, which can be a bit splashy...but I pressure was the deck and the edges of the patio that will get damp and mossy over the winter. If we get a heavy rain, there can be some water get through along the house, but the house eves keep it dry most of the time. I am planning to replicate this system on the other half of the deck, but will likely use a gutter along the house and the deck beam and that should help catch water that gets through along the house. Thanks for sharing your process...I wanted to see how others were avoiding the commercial systems, so this is one alternative! Cheers!

[@fitdev1291]

Great video! What of i have a swing bed under, how would I go about attaching the stuff through this roof without leaks? Any advice would be appreciated.

[@johnvcougar]

I take it you guys didn’t build that deck, correct?

[@duchessofdartmouth2683]

Perfect! I love the little details - use a vice, (got an old one from my father-in-law) use blue tape for hole depth. I want to do this under my first-floor deck which is over dirt in my sloped backyard. I want to store garden tools under the deck and keep them dry in winter. Although the title is Dad&Son, I only saw Dad working. I will keep this in mind as I want to ask my daughter to help me. I'm 64, and a bit weaker than I was 4 years ago due to cancer treatment but I know that with a helper, and your detailed video, I can tackle this job! It's raining in San Francisco now, but I will at least take measurements and make a supply list.

[@DyzeDyze]

Great video, thanks, don’t you put caulking where panels and wall connected? And it’s better to cover under the deck extension to prevent animal entering there.

[@anamsurfer4672]

Do you need j channel along house ?

[@billbradleymusic]

That's called soffit. I'm a concrete guy BTW

[@thedwightway1087]

Did you run into any mold issues between the roofing material and the deck wood?

[@DadandSonDIY]

We haven't so far. While moisture can build up, it shouldn't be an issue with enough slope for the water to run off.

[@AppyBuilder]

Great video. What software did you use for 3D modeling of under deck?

[@sonjaponath4914]

I swear it looks like you have a house in my neighborhood! Where are you? This is exactly what we need to do to take advantage of that space under the deck. Just need to get my son and husband to do it then!

[@vishbills]

Hello there .. great video .. one quick question regarding the noise level .. would you hear anything underneath the deck during rains ??

[@cshekhar]

Very informational and descriptive instructions. Thanks. I was looking for something for a while.

[@raggedymanInd]

after some time it is bound to get clogged with leaves and such. How will you clean it out?

[@Justbase]

Good job, buddy! Simple, elegant and inexpensive.

[@frankmahoney3166]

You could save a little headroom and time by starting with a 1x 4 instead of a 2x4, then use a 2x4 in middle and a 2x4 with a spacer towards the front

[@DadandSonDIY]

That works just as well. Great Idea.

[@melaniekirk1451]

It seems that it would be better to use the spacer method for drainage and for clearing any debris that builds up....and possibly to allow more air flow to help avoid mildew. Just an opinion.

[@dirtysalmonchaser]

He had to start with a 2x4 as he had 2x4 bracing already on the roof of the deck and had to clear that to get the proper slope.

[@hdhome1205]

@@DadandSonDIY ​ @BuildItMike ​ @melanie kirk - Any chance I can just use multiple spacers and screw-in the panel right on the spacer instead of using the three 2x4s? In other words, what purpose does the 2x4s serve besides adding thickness to the spacers? Thanks!

[@DadandSonDIY]

@@hdhome1205 The panels are thin and need to be screwed in at regular intervals. The 2x4s are what they screw into, so just having just spacers would remove that support.

[@snozcocram]

Does anyone have a solution for the fact the spacing of the corrugated panel and the attachment point is only 3/4”? In my area we have a seed from the trees that tend to block even the rain gutters at the seams. I can imagine these seeds making dams on the ceiling surface which would then inhibit drying times or even cause rot and termites from dampness. By solution I mean a tried and tested design. Thanks

[@hthudson01]

How is your roof holding up? My concern about the method is that the spacers will quickly rot from water exposure and your roof will start coming down when the spacers fail.

[@DadandSonDIY]

The roof is holding up great! We are actually a little supprised how there has been no maintenance needed, considering we live in the Seattle area which is pretty wet and are surrounded by pine trees. We didn't do this but if you are concerned about the spacers rotting, you could always seal them first.

[@darkav0]

had a similar build under my deck when i bough my house. Unfortunately that is correct. Pine needles and other stuff will get in there and eventually, from constant moisture, start rotting the spacers and underside of the deck boards. Also, most of those deck screws will also start to rust within 2 year span and if no rubber washers used, there will be water drips forming. Im planning on rebuilding the roof, but i would not repeat this build type, its better off to give it more angle and set it on its own posts

[@DadandSonDIY]

@@darkav0 Sorry to hear that your old roofing hasn't held up. Ours has been holding up wonderfully but its expected to vary with how many trees you've got. The roofing screws we used had built in rubber washers so that was nice. Also to prevent rot, its probably good to remove some deck boards from above every free years and hose the panels down, washing away the pine needles.

[@mariazambds]

Can you please add the link for the next video in this series of underdeck?

[@traceymayrand2071]

Thanks for the info! Nicely done and super helpful!

[@markcorwin270]

How did you seal around the deck front to keep it from leaking?

[@jkreviea]

@2:11 lol!

[@irishpirate6779]

what is the name of the product/material ?

[@kenchan529]

been a couple years curious as to how its holding up

[@jimbonevideo6941]

Do you have any leaks near the ledger board at the house?

[@om0039]

How did you seal the side where the roofing panels meet the house wall?

[@DadandSonDIY]

We didn't. We just put the panels up as close as we could.

[@docmag1983]

Probably better to not seal off so air can move around and reduce moisture

[@johnvcougar]

Flashing may be a good idea if prevailing conditions dictate.

[@briangray7614]

Well done. It’s great to see a father and son working together and I appreciate the honesty of the video. 😉

[@LuisEzequielDeLuca]

I am getting this wrong or the spacers are higher where the gutters are, if I saw that correctly the water will be going towards the house. Despite that looks clean when done. I would probably add 4 2x4 instead of 3 just in case

[@DadandSonDIY]

Nah, the water goes towards the gutter, away from the home; I think you misinterpreted something. Also, 3 2x4s had been working great for us over the past few years, but nothing wrong with 4.

[@amgaming3960]

Excellent Video, What I am looking for. your explanations are very clear. Good Job guys.

[@snegash86]

I really like what you guys did. And the explanation was amazing. Can I ask you what kind of nails you guys use for the panels? also did you guys use any type of sealing to prevent any leak near the house wall?

[@DadandSonDIY]

We used 1 ½” Hex-Head Roofing screws. They have rubber washers that prevent leaks. We din't add any sealing against the house because the pre-existing deck already had one.

[@devhero4207]

What kinds of panels are used?

[@sandygomez3439]

What gutter system did you guys use?

[@uhogmo]

What is the length of the polycarbonate panel?

[@gylesdias2900]

Well done! Really well explained! Thanks

[@satzawesome]

I did this 4 yrs ago and how do you handle the water coming down in the rear against the wall of the deck. ? .

[@DadandSonDIY]

The roof of the house overhangs the wall by about a foot, so most water doesn't reach that portion of the deck. Also, the roofing panels that we installed are pressed up against the wall. Very little water, if any, comes down there.

[@am20093]

Thanks for posting this!

[@DadandSonDIY]

Glad you found it helpful!

[@jcolinmizia9161]

Thinking of doing something similar. How much did this all end up costing?

[@DadandSonDIY]

Sorry, don't remember the exact cost, though it was pretty inexpensive. Prices for 2x4s will be higher now than when we did this project because of covid, but everything should still be $500-$1000

[@Stewy2550]

That's absolutely awesome

[@joseacd01]

Thank you

[@DadandSonDIY]

No problem! :)

[@raghavaraju8609]

very clear and helpful

[@Mr1saveme]

nice work!!

[@DadandSonDIY]

Thanks Scott

[@lindabatstone9209]

Abc

[@multicarepharmacy3640]

very good video , thanks a lot for training . keep up the good work :)

[@DadandSonDIY]

Glad you found the video helpful!

[@rudeboy3492]

What size are the roofing screw? 1 inch?

[@DadandSonDIY]

They are 1 1/2"

[@johnfuquajr5061]

Nice video. I'm about to install it now.

[@DadandSonDIY]

Let us know how it goes!

[@katiedeboerable]

Hi there! Thinking of doing this to my deck. Thanks so much for the very helpful video! Question: I have a hanging hammock chair attached to one of the joists already. Do you think I could reattach that though plastic or aluminum panels, or would that cause a whole in the water system?

[@DadandSonDIY]

As long as you attach the hammock into the joist with the screws shown (with rubber gaskets), it should be fine. I don't see how it would be any different from the screws holding the panels to the joists.

[@sheensbling3302]

Will it leak im affraid the water could sit in top cause mildee and leaking what you suggest

[@brucen6579]

@@sheensbling3302 I'm facing a similar issue with a porch swing. I'm hoping to find a way to divert the water around the 2"X4" openings I'll have to make in order to allow the swing to swing. Another option might be to make sure the brackets fall into the top of one of the ridges and then screw them on. This will involve longer lag screws on one end since that end is roughly 2" from the joists in order to allow for run-off. Any ideas appreciated....or I just might have to deal with a small amount of leakage.

[@uhogmo]

what is the span of the 2x4support

[@DadandSonDIY]

It will be different for everyone because it needs to be the length of your deck.

[@tb693ny6]

how much was it in material

[@number6204]

what washers did you use?

[@DadandSonDIY]

The washers came with our Hex-Head Roofing screws.

[@joserivera5008]

Oh boy he has a rigid!!

[@DadandSonDIY]

yessir!

[@thermant8452]

😢 this is beautiful

[@BroncoColdsteel]

Well done, nice video. Cheers!

[@DadandSonDIY]

Thanks!

[@كُنكالمطرأينماوقعنفع-ش5ص]

👌🌹❤️

[@joelalleman9591]

thank you for sharing this !! I've been wanting to do this under my deck for several years and you just showed me in very simple language and instructions how to do it , THANKS !!!

[@karieburt125]

What a great video! This gave me exactly what I was looking for, it was so clear and helpful and well presented. Kudos!

[@howtodoitdude1662]

Why didn’t you cut the last 2x4’s that laid over the cross members?

[@Saltbox97]

HowToDoItDude I think that one had a spacer above it. I was thinking the same thing at first. I would have removed that cross member first as it is not needed after decking is on. It is a temp to keep joists from racking before floor decking is in.

[@IMGreg..]

Build a pitched deck and you don't need offset spacers to get water to run. This gets it off your deck boards and whatever you use under the deck will have the needed pitch when fastened to the joist. 1 to 2 in over 6 or 8 feet isn't a noticeable pitch when using the deck.

[@truhbf]

Hoping to do this at my girlfriend's house, possibly with metal roofing. This is the precise approach i would take! My parents had an official under deck system installed. Cost thousands and i have adjust it to prevent leaks a few times per year.

[@DadandSonDIY]

Hope the project goes well for you!

[@hotrodpaully1]

You don't have enough support for those plastic panels in a heavy rain or over time they will bow and collect water Would have been ok with metal panels but those plastic ones need more support

[@DadandSonDIY]

The project was completed over a year and a half ago and the roofing has held up fine with no signs of bowing. Additionally, the shape of the panels' corrugations makes it very stiff in the direction of its length, making it even less likely to bow in the future. We appreciate your concern, and will keep an eye out for any need of maintenance in the following years, but believe that the amount of supports are sufficient for the size of our deck.