i live in new england. my biggest question is not whether or not to use a radiant barrier, but how much insulation works best with it? The house i just moved to has very little insulation in the attic. Should i beef up the insulation first or only add the radiant barrier?
Ed, I have a question that I can’t find an answer for in your articles.
Background info: house built in 2006. Radiant barrier installed then. House roof damage from storm in 2019. House reroofed but radiant barrier not repaired. Radiant barrier has some extra holes and some missing. Partial from age, roof damage and being reroofed.
I have purchased radiant barrier from your company and done some repairs myself. Then I had new blown in insulation installed. The insulation covers the ventilation gap at the soffit level (no baffles installed to keep insulation from covering the soffits or dropping into them. So I am concerned about correct air flow.
My question is: Should I worry about the blown in insulation being above the air gap? Is that possible blocking air flow? I can’t tell yet if any insulation has dropped into the soffits. What is the best way to check this abd correct if needed.
FYI: I have a temperature gage for checking the heat in the attic. Temps have ranged from 97 to 125 depending in the area I check. I know the insulation is the most important to check. The higher temps are on the radiant barrier. Especially in the rafter vented areas.
One more question. In the top of the rafters can I cover that opening as long as I allow for a ventilation gap?
Re:Should you worry about the blown in insulation being above the air gap? Ideally you should have the air gap open so that the main attic space gets outside air. This keeps the air temp lower AND dries up moisture, preventing issues with condensation. The gaps at the peak of the roof should remain there – do not close that off. The best way to check this is to crawl into the attic and look. You can retrofit baffle vents to help keep the insulation away from the soffits.
Linda, there isn’t really a way to do it without pulling down the sheetrock and emptying out the cavities OR without losing ceiling height. The foil HAS to have an air gap in order to work, so you have to create that gap either in the cavity or on the ceiling, which decreases the height in the room.
Good evening. Thank you for sharing your knowledge. I live outside of Houston so it’s very hot and humid for the majority of the year. I want to insulate an open frame (2×4) shed that has a gambrel style roof. I want to use a radiant barrier (after an air gap I will make with foam firing strips) and then butt up some rigid, open cell foam board to that. Is 1/2” a sufficient air gap or should it be thicker, nominally? How does the foil-faced foam board compare to using foil and then rigid foam board? Thanks, again.
1/2″ is the minimum air gap I’d go with. If you’re able to get a little bit more, go for it! But no need to have an air gap any more than 1″ for the foil; it would aid in ventilation with better airflow though. There’s probably not a lot of difference between foil + foam board and foil-backed foam board. You can check the specs to see what kind of aluminum they’re using, but it is likely to be comparable.
i live in new england. my biggest question is not whether or not to use a radiant barrier, but how much insulation works best with it? The house i just moved to has very little insulation in the attic. Should i beef up the insulation first or only add the radiant barrier?
Thanks
Lee,
Radiant barrier is NOT a substitute for standard type insulation. Check your local codes to see what is recommended for your area.
Ed, I have a question that I can’t find an answer for in your articles.
Background info: house built in 2006. Radiant barrier installed then. House roof damage from storm in 2019. House reroofed but radiant barrier not repaired. Radiant barrier has some extra holes and some missing. Partial from age, roof damage and being reroofed.
I have purchased radiant barrier from your company and done some repairs myself. Then I had new blown in insulation installed. The insulation covers the ventilation gap at the soffit level (no baffles installed to keep insulation from covering the soffits or dropping into them. So I am concerned about correct air flow.
My question is: Should I worry about the blown in insulation being above the air gap? Is that possible blocking air flow? I can’t tell yet if any insulation has dropped into the soffits. What is the best way to check this abd correct if needed.
FYI: I have a temperature gage for checking the heat in the attic. Temps have ranged from 97 to 125 depending in the area I check. I know the insulation is the most important to check. The higher temps are on the radiant barrier. Especially in the rafter vented areas.
One more question. In the top of the rafters can I cover that opening as long as I allow for a ventilation gap?
Thank you,
Patti L
meowhaven@gmail.com
Re:Should you worry about the blown in insulation being above the air gap? Ideally you should have the air gap open so that the main attic space gets outside air. This keeps the air temp lower AND dries up moisture, preventing issues with condensation. The gaps at the peak of the roof should remain there – do not close that off.
The best way to check this is to crawl into the attic and look. You can retrofit baffle vents to help keep the insulation away from the soffits.
We are looking for a radiant barrier for an open beam structure that does NOT require an air gap. Possible?
Nope, not possible to have a radiant barrier when there is no air gap. Reason is here: No Air Gap? No Radiant Barrier.
Is there any way to add radiant barrier to an existing vaulted ceiling? There is no crawl space
Linda, there isn’t really a way to do it without pulling down the sheetrock and emptying out the cavities OR without losing ceiling height. The foil HAS to have an air gap in order to work, so you have to create that gap either in the cavity or on the ceiling, which decreases the height in the room.
Good evening. Thank you for sharing your knowledge. I live outside of Houston so it’s very hot and humid for the majority of the year. I want to insulate an open frame (2×4) shed that has a gambrel style roof. I want to use a radiant barrier (after an air gap I will make with foam firing strips) and then butt up some rigid, open cell foam board to that. Is 1/2” a sufficient air gap or should it be thicker, nominally? How does the foil-faced foam board compare to using foil and then rigid foam board? Thanks, again.
1/2″ is the minimum air gap I’d go with. If you’re able to get a little bit more, go for it! But no need to have an air gap any more than 1″ for the foil; it would aid in ventilation with better airflow though. There’s probably not a lot of difference between foil + foam board and foil-backed foam board. You can check the specs to see what kind of aluminum they’re using, but it is likely to be comparable.
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