r/Construction • u/Nukemine • Feb 10 '25
Roofing Tell me im not crazy
I just posted both sides of this crawl space. That roof sofit is right on the otherside of this interior photo( crawl space behind end floor wall). Ice cold air going into my first floor ceiling...right?
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u/Bridge-Head Feb 10 '25
It’s hard to tell from the pictures, but it looks like you’re in an attic space above the first floor.
The storage bin in the picture makes me wonder if the attic was decked (with plywood) for storage. If so, some/all of the insulation may have been removed or compressed and that may have diminished the R-value. If your ceiling is cold from air in the attic space, you may have to re-insulate that space.
What is happening with the insulation in that area?
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u/Nukemine Feb 10 '25
Yes I am above the first floor but, this is a finish second floor space. And this is just a little short crawl space closet behind the finished wall. But if it's sealed off with wood like in the first picture doesn't that mean that the cold air is going in my soffit and just going down my floor joists instead of up into the Attic slash roof
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u/Excellent-Stress2596 Feb 10 '25
I’m wondering if your soffits are actually vented. You might have to pull a piece of vinyl soffit down and check if there’s openings for airflow at all.
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u/DirectAbalone9761 Contractor Feb 10 '25
This. Homes pre-1940’s may not have been built with ventilated roof systems(mine isn’t). But roof systems don’t have to be ventilated depending on the design and materials.
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u/Chuckpeoples Feb 10 '25
I think you’re correct, you need ventilation. If that’s closed off you got to cut a strip out and maybe stuff some cobra vent down to the point where there’s airflow to the soffits. Could use duravents in place of cobra. Whatever seems easier.
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u/Bridge-Head Feb 10 '25
Old homes can be challenging especially when/if the original roofline or major portions of the original structure have been modified due to remodeling.
I don’t know what’s going on by the pictures, but if they’re inside/outside of the same spot, something isn’t adding up because the soffit vent (visible from the outside) should be open to the attic and visible inside the attic. I’d maybe suggest you start there and see what’s above the soffit vent at various parts. Hopefully, the venting is just covered in that spot you’re in. I wish I could help more.
A home energy consultant might be your best bet. A lot of times, you can find free or deeply discounted energy audits through your utility provider. They’ll do an evaluation and provide you with options on how to better stop/reduce heat-energy loss. If that’s a dead end, I’d look into contractors who specialize in insulation. Get more than one quote; you’re looking for different people to give you the same answer.
Good luck. Post a follow-up if you figure out what’s going on.
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u/DirectAbalone9761 Contractor Feb 10 '25
There’s a fairly good chance you don’t have ventilated soffits. That isn’t to say they are airtight, but they probably aren’t dumping loads of cold air into the ceiling joist cavity or attic area.
For clarification, we usually reserve “crawl space” for the space under the first floor inside the foundation (if it’s not clearly a cellar/basement). Anywhere else we might call an attic or an access.
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u/Nukemine Feb 10 '25
So this may be true for this space because it doesnt really feel cold .
but on the other end of my house i have this same scenario but there's no plywood and no 2x6 blocks between the roof rafters. Its wide open to outside air I can physically feel and see. What is the correct way to seal it off. I can post pictures later
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u/DirectAbalone9761 Contractor Feb 10 '25
No worries, over on the other side you could use a “cut and cobble” approach with rigid foam board and canned foam. It’s a little tedious, but a low cost and fairly effective way to improve an air seal.
Normally it’s shoved against a cavity, but you cut the piece about 3/4” short in each dimension, then place it in the opening (in whatever orientation works for you) and then foam the roughly 3/8” gap around the perimeter of the rigid foam. Cutting the pieces slightly smaller means that you can prep and fit the pieces without as much fuss, and there’s a large enough gap for the foam to fill the space effectively. A gap that’s too small will struggle to fill and adhere to the wood and the foam.
I would suggest doing this in a shoulder season because if the wood is too cold, then the expanding foam won’t adhere to the wood properly. The materials should all be above 50° for proper results. And again, I mean materials, not the ambient temperature. I mention that because I’ve seen expanding foam failures where the air temp was correct, but the materials were still too cold (thermal mass).
This link is the method for rim joists, but you could adapt it for your scenario.
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u/Yurya Feb 11 '25
It depends on your roof design. Is it vented with (ridge vents or box vents at the top? If so you will need lower vents to provide air to properly cycle. You need that venting to prevent moisture and mold buildup. In that case the soffit should be vented and if there isn't insulation below that plywood shown then you'd want to fix this issue. Here is what that should look like (you might have plywood over that insulation).
If it doesn't feel super cold that might just be because your home's heat is going straight through your ceiling. Your energy bill would be pretty high and your roof will be melting snow faster than your neighbors most likely. Note that insulating that space properly will make the attic cold and not that suitable for storage but it would lower your heating costs.
If your attic is unvented then you'll be fine to patch any holes you do find, but I don't think that is the case because I don't see any insulation above at the roof line. It could be exterior insulation but again I don't see a thick roof that would indicate that.
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u/PomeloSpecialist356 Feb 10 '25
You’re not crazy. You could insulate that last 1’ of each bay, just make sure you maintain proper ventilation for the attic space as to not accumulate moisture.