Timber Frame Cabin: Vented Roof Installation

Time Lapse of May 14th - 24th where we installed roof insulation panels, purlins for venting and a standing seam metal roof
Check out our website for more details:
offgridburbia....
Music by:
www.bensound.com/
#ventedroof #roof #naturalbuilding #diy

[@sonyaoconnor4354]

Just started following, looks great!!

[@offgridburbia]

Thanks!

[@danielmaddox584]

wardrobe malfunction-the music: *oh yeah*

[@offgridburbia]

That little sound bite put a copyright strike on this video but I think it was worth it.

[@darrenscott1111]

Ohhhhh Yeah!

[@davidbruce5377]

I wish you had close up angles

[@offgridburbia]

Yeah, this is one of of my earlier videos. The videos have gotten better but I haven't done another vented roof since this one. My blog post has some close up pictures and more detail: offgridburbia.com/roof-installation/

[@jonbergin4330]

What product did you use for the vent strips(rectangular black strips)?... also, what did you use for the wooden square blocks-looks like 1/4 x6 plywood squares(2 of them?...on the fascia boards...thanks.

[@offgridburbia]

Hey Jon, The black strips are CorAVent strip vents www.cor-a-vent.com/ps-400.cfm I bought them from a lumber yard. The vent strips are 1" thick so I used two 1/2" thick plywood squares as spacers. Check out my building blog post about the roof build. I have some still shots with more details: tframecabin.blogspot.com/2019/05/roof-installation.html

[@piratemakers]

great video ! I wonder how did you fasten the plywood on top of the foarm sheets ? It must be at least 4" or 6" of insulation + 5/8 plywood to go through ?

[@offgridburbia]

I used 8" screws I bought from the roofing supply place.

[@e.r.1492]

I was going to ask this.... I figured I’d make sure no one else did first lol

[@davidbruce5377]

I am doing a very similar building - thats why i stumbled on your video. Could you assist me with something? I am building a single story wood frame in The Philippines and my architect and engineer there are not dialed into wood framing design. Is there a design aid and spec tool they could use? That you have used. I have 7k board feet of cut and dried 2x6, 2x8 and big beams of mahogany - ready to go.

[@offgridburbia]

I calculated the total weight of the roof. See spreadsheet here: docs.google.com/spreadsheets/d/1x2mXfM9LH7I09YhSJ4pPgEwyNJtNikGv/edit?usp=sharing&ouid=102759157513719220351&rtpof=true&sd=true Then I used the timber tool box beam calculator to determine the rafter size. In this case I used 4x10 douglas fir on 36 inch centers with a clear span of around 15 feet. Here's the linke link to the timber tool box calculator: www.timbertoolbox.com/Calcs/beamindex.html In this article/video, I talk about calculating roof loading for a living roof: offgridburbia.com/living-roof-install/ Shoot me an e-mail if you need some help. Contact details are here: www.youtube.com/@offgridburbia/about

[@n00bi3b4sh]

Hello there, great work. I just tumbled over your videos today, looks like you guys are doing a fantastic job. Is there any more information about the design of that house. Have you bought a timber package somewhere and assembling everything on your own or are you a contractor? Great videos I already subscribed and hoping for videos of your progress. Good luck to you

[@offgridburbia]

I modified some plans I got from timberframehq.com/. I'm blogging about our project at tframecabin.blogspot.com/. You can check out the project overview and my plans there. Thanks for watching!

[@andysparks7381]

What was the main reason for installing the plywood on top of the foam? Was it to give the membrane something hard to fasten to?

[@offgridburbia]

Yes, and to give the purlins something solid to attach to. I've seen a peel and seal membrane attached directly to the foam and then purlins laid down directly on top of that. kzbin.info/www/bejne/eqHbfZyVh9JmZtU The 8" roofing screws I used to attach through the foam to the roof deck were difficult to drive so I just found it easier to use the plywood as an intermediary step.

[@andysparks7381]

@@offgridburbia I believe I am using the same plan as you used from Timberframe HQ. I increased the size to 26 feet x 18 feet. I am going to do the walls a little differently than you, however, but I like what you have done. Thanks for the reply. I may have more questions for you as I get farther along.

[@offgridburbia]

​@@andysparks7381 Yeah, I would do the interior framing with double walls if I was doing it again. If you go to my building blog you can find my contact details in the about me section. tframecabin.blogspot.com/

[@leliu5thelement448]

I like this design and want to build a cabin but modify to 60x40...home design plans?

[@offgridburbia]

I don't think this design (particularly a monoslope/shed style roof) would lend itself very well to those dimensions. My plans are up on my building blog check them out at: tframecabin.blogspot.com/

[@acadian101]

hi there ,,i was wondering what are the dimensions of this cabin as i'm looking to do something very similar. im curious as to what is the size of your roof rafters 2x12? and what is the span? cheers

[@offgridburbia]

The cabin is 24 feet by 16 feet. The rafters are 4x10s on 36 inch centers. The span is just under 15 feet. If you're going to use 2x dimensional lumber I would use a rafter span table like this one www.southernpine.com/app/uploads/SPtable39_060113.pdf

[@deltafour1212]

I am curious, why you didn't put the purlins straight from the ridge to the fascia as most do when installing metal roofs? Instead, you did i a 45 degree angle? Is there an advantage to this?

[@offgridburbia]

There's a continuous vent that runs along the entire perimeter of the roof. The diagonal purlins give warm air a pathway from the low side of the roof to vent out on the high side of the roof. Likewise, any moisture that ends up between the underside of the roof panels and the waterproof membrane on the roof deck has a way to drain out. Check out this Matt Risinger video for more details about the purlins on 45° angle: kzbin.info/www/bejne/eqHbfZyVh9JmZtU

[@deltafour1212]

@@offgridburbia THANK YOU!

[@deevious1431]

Do you have the plans for this build? This is exactly what I'm looking to build.

[@offgridburbia]

No, I never produced a formal set of plans. After a few years of living here I've been thinking about publishing a "What I should have done" guide.

[@jacobyhomestead]

@@offgridburbia I am curious what a bullet-point list would look like for this! haha. You did a fantastic job with this build. I would love to build something very similar and get first-hand knowledge about the possible pitfalls I would encounter.

[@offgridburbia]

@@jacobyhomestead 1) Smaller is better (at first at least). The cabin was 384 sqft plus loft and took me mostly working on my own over a year and half before we could move in. The cottage (our more recent build) is ~216 sqft and took about eight months before it was livable and 10 months for the interior to be completely finished out. The cottage is better designed is built. My wife and I have talked about how we wish we had built them in reverse . 2) Stick to a single story. Once you have to move on to ladders or scaffolding a build really slows down. 3) Orientate your building for your site and the building's function. I think this mostly correct for both buildings. The cabin only has south and north facing windows has no east or west facing ones (so we only have solar gain in the winter). The cabin has a south facing sloped roof for mounting solar modules. The cottage is partially earth-bermed, has a living roof and tree cover so its solar aspect was not as important building with the contour of the land in mind. 4) Minimum roof overhangs of 2-3 feet and even more is better (unless you live in an area with high winds). 5) Document your build with a blog and lots of pictures. I often refer back to my notes and videos.

[@daveberry342]

How is the roof holding up ?

[@offgridburbia]

It's doing well. We did have a carpenter ant infestation the first year because they like nesting in the poly iso foam board and we had a tree limb contacting the roof for a while during construction which I guess was their avenue for access. Since they were evicted we haven't had any issues.

[@daveberry342]

Thanks, the robust design made me interested.@@offgridburbia

[@offgridburbia]

I haven't thought of a good way to gather metrics to measure performance. I've heard since building it that vented roofs are best on steep roofs and ineffective on low slope (below 3:12 pitch) ones. Ours is 4:12. @@daveberry342

[@everythingisawesome1032]

I have a very similar build on my project with the roof essentially being about the same. Did you use open cell polyiso for your insulation? Also did you just vent roof through the fascia? I was looking at a product from Cora-vent, s-400 for my venting through the fascia board. Any info would greatly help! Thanks.

[@offgridburbia]

We used polyiso foam boards for insulation and vented through the fascia with the Cora-vent S-400. Here's a link to the blog article about roof install where you can see how we attached the cora-vent: offgridburbia.com/roof-installation/ The only issue we've had is that carpenter ants think polyiso foam board is a prime nesting area so we have to remain vigilant.

[@everythingisawesome1032]

@@offgridburbia Is your polyiso closed cell or open?

[@offgridburbia]

@@everythingisawesome1032 Closed cell

[@everythingisawesome1032]

@@offgridburbia did you spray and Bora treatment on your Timbers or framing??

[@offgridburbia]

@@everythingisawesome1032 Not with this build. I figured being pier and beam and with all the sub floor materials being pressure treated I would have a little buffer from the termites. With my current project I'm building on a grade beam so I sprayed a borax solution on the studs and put it in the light clay straw slip.

[@xfoxtrotwiskeykilo995]

That was a statement not a malfunction !!!

[@offgridburbia]

I agree. I think it was a premeditated malfunction.

[@Michyhauser]

Are those SIPS?

[@offgridburbia]

No, those are just polyisocyanurate insulation panels. At the box stores they sell them in 1/2" - 1" thickness. I got these 3" thick panels from a roofing supplier.

[@jonbergin4330]

@@offgridburbia 2-3 inch panels right?..what was the total r-factor then?..thxs.

[@offgridburbia]

@@jonbergin4330 The 3 inch panels have a ~18 R value. I used two layers so that's an R value of around ~36. So with the roof deck and the plywood on top of the insulation panels the R value of the roof is just under 40.

[@jonbergin4330]

@@offgridburbia thanks for that information...enjoyed your video and description.