Framing Gable Roof Overhangs
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- Опубліковано 27 сер 2024
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Deep overhangs need cantilevered support outlooks that tie into the roof framing
With the roof framed. You’re almost ready for sheathing. Before slapping down plywood, though, you need to frame the gable overhangs.
In another animation, we assembled a simple ladder-block overhang and nailed it through the wall sheathing into a rafter.
Subfascia ties together the bottom, and roof sheathing acts as a structural diaphragm above to form a torsion box of sorts.
This works great for small overhangs, but what if you want to upgrade to a deeper overhang?
How is that framed?
It will be done with a similar ladder frame, but the system is a little more involved than blocking.
It involves notching the outermost rafter to accept 2x4 outlooks.
The 3.5 x 1.5-inch notch should be spaced every two feet and placed to land where roof sheets will break.
2x4 outlooks should extend back to the second rafter and past the first one by whatever the overhang is minus the thickness of the subfascia.
Make sure to square up the outlooks before nailing them through the inner rafter. Nail through the face of the outlook into the notch of the outer rafter, and you’re ready for subfascia.
Now you can slap those sheets down, staggering the rows, and keeping them on layout. With the roof sheathed, it’s time to take a break.
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Thank You! I had a roofer come out to look at a leak and he started saying these words “overhang” “drip edge”. Etc…. I just nodded like I knew exactly what he was talking about. Thank you for explaining this to people like me!
lol, we all do that don't we!
Glad it helped.
Its time to take a break... Right into the toilet!!!!! babahah~~
We like to call it the Green Room
@@ProTradeCraft yes sir!!! Haha
du bist ganz toll und tolle Erklarungen💯
Danke
Nice and concise! My kind of video right there, great job
Thanks, bub.
They are called “look outs”
a colloquial term that is not used universally.
I am planning on adding an 7 inch overhang (final depth after siding will be 5 inches) to an existing structure that had no overhang. Is it ok to attach the 7” ladder block directly to i assume the front rafter and not have to notch at all? My contractor wants to build it out stacking 4 rafters nailed and screwed into eachother without the ladder technique but i thought that seemed unnecessarily heavy and not as strong. Thoughts?
Also, since its only 7”, would the sheathing still need to extend inward such as in ur animation or would smaller pieces added just on the new ladder block suffice. Thx
You can probably screw the ladder blocks into the rafter, using structural screws, but tie the roof sheathing into the existing roof. A LOT.
is it really ok to notch out a 2x8 rafter like that for the 2x4 supports?
yes.
Yes, because the 2x4 becomes part of the compression part. That's why the notch has to be tight tolerances. No slack. As always, check with local code and your building inspector.
Would it be the same for a truss roof?
No. Engineered trusses are engineered to work as a complete unit, not as a notched one. This would be something you'd discuss with your truss designer. I have seen some gable trusses that are dropped 3-1/2 inches, to accommodate the outlooks. Do not modify engineered trusses without the adult supervision of an engineer.
Thank you for this explanation. I was thinking of using T&G as roof sheathing just around the parameter so it is visible from under the overhang. And then plywood for the rest of the roof. With either the ladder method or this method, does the T&G need to extend back to a second truss to tie it all together, or can the T&G just cover the overhang? This is just for a 10x10 shed. Hope that makes sense.
Definitely run your plywood to the overhang and use T&G on the bottom as soffit material if that’s what you’re going for.
As noted above, it is certainly better to tie the structure together.
Interesting stuff!
Thank you.
how big of a overhang can you have with blocking before you have to notch?
I mean, any more than a foot and I'd do it.
What's the deepest you can do an overhang with this method?
depends where building is geographically, building exposure, and what you mean by “can” - if you mean “can” as in no deflection under any conceivable snow or wind loadings…. it is a function of overall geometry and the stiffness (you generally do not want elastic behaviour in wind conditions so don’t design to elastic limits) of the sheathing + nailing pattern used. the depth of the structural eave and the ridge detail at the structural eave matters for wind uplift loading.
this is an area where most codes let you do some pretty janky stuff that is not very good. to my mind there are two main concerns: 1) safety 2) callbacks (including for water)
therefore best to design something that pretty much never flexes any more than the rest of the roof, using some actual understanding of what wind loads are involved…. the uplift loads, not just the self-weight loads, get bigger the more soffit area is exposed. the worst case uplift loads get bigger faster than the self-weight loads get bigger.
@@2brazy4ubitch Can you convert that to inches?
@@KingofFools No more than 18"
Great vid! If you wanted a longer or stronger overhang, would you build with 2x6 over a 2x4? Asking for a friend in coastal Florida😉
Depends. Longer overhangs protect the walls better, but they also catch the wind. If you are in a hurricane zone, like most of Florida is, it may be wise to consider that.
I know a builder in North Carolina who designs overhangs to be break-away, so that when a flying tree takes it out, it does not cut a hole in the roof. The majority of damage from hurricanes is often water that gets in.
If the roof is tight, the damage is significantly minimized.
Thank you for the excellent vid. Question: What are your thoughts on orienting the 2x4 lookouts so the notches would be 1.5 inches wide and 3.5 inches deep?
@h2s142 Thanks.
Is this fine for snow loads? I live in North Idaho and I’m building a porch
This is how we framed them in Western MT. obviously, bigger overhangs hold more snow. Steeper roofs, shed it faster, and engineers can answer technical questions that we can only speculate about.
What is the name of the software you are using?
looks like SketchUp
ding ding ding!
Sketchup
correct!
Thanks, yet it seems not scaled. if you cut 1.5" in 2x4 truss, it has no strength. so, you need 2x6 on end truss, yet 2x4 in common truss, anyway structure will not like your video, which might be ok for truss all use 2x6 but it is not the real world.
The roof is not framed with 2x4 trusses. It is framed with solid lumber. When ordering engineered trusses, you need to specify how you're going to build the house. Sometimes, a gable truss will be shorter, allowing outriggers to rest on top, othertimes, engineers will make the top course of tha gable truss thicker to allow notching.
DO NOT MODIFY ENGINEERED FRAMING UNLESS APPROVED BY A STRUCTURAL ENGINEER
Framing with solid lumber is MUCH DIFFERENT than framing with engineered lumber.
@@ProTradeCraftwhat’s a structural engineer cost?
Link to ladder block animation possible? :)
ua-cam.com/video/vSBXovDAr0o/v-deo.html
👍👍👍👍👍👍👍👍👍
:)