We have made good progress on the attic insulation over the last 2 weeks. The first layer of the rigid foam is done and the fiberglass has been started.
Looks good but would be concerned with thermal bridging with your approach. I'm also significantly improving my attic insulation. I'm not putting in a bonus room though. I used R19 batts for the roof trusses and am adding a second layer of R30 batts on the attic floor for a total R79 attic insulation. I have a huge attic so this is a big project but will payoff in overall home comfort as well as lower utility bills. Another big benefit is sound deadening.
There will definitely be some heat loss through thermal bridging but I decided it wasn't cost effective to address that issue since I believe the heat loss will be minimal. So far, the space stays between 68 - 72 degrees all year long with no heat or AC. Sounds like you have a big project ahead of you, good luck and thanks for your comment.
I really like the white foam board. Who makes it, where did you buy it The r21 is probably overkill with the foam board but as long as you have your air gap from bottom vent up to your rig cap you should be good. Your going to notice a huge temp difference in that area. Great job
They manufacture color coded builders spacers in mm increments that you can use to level the battens which might have made it easier the. Using random offcuts.
Would have been worth it to use blown-in insulation (the packed in kind) between foam boards instead of fiberglass? I agree with you that the thermal bridging probably wasn't worth any additional effort. I wish I could find some foam board like yours.
The blown in would have been faster and maybe slightly higher R-Value but would have also been much more expensive. I prefer to do it by myself and my R Value is already plenty high. Thanks for watching.
You can always add another roofing layer on top with vertical battens under that for air flow. radiant barrier (aluminum product) under or over (or suspended between double layer batten = best) the battens would help a lot with preventing a lot of the Sun's heat from ever reaching the insulation in the attic.
Looks good but would be concerned with thermal bridging with your approach. I'm also significantly improving my attic insulation. I'm not putting in a bonus room though. I used R19 batts for the roof trusses and am adding a second layer of R30 batts on the attic floor for a total R79 attic insulation. I have a huge attic so this is a big project but will payoff in overall home comfort as well as lower utility bills. Another big benefit is sound deadening.
There will definitely be some heat loss through thermal bridging but I decided it wasn't cost effective to address that issue since I believe the heat loss will be minimal. So far, the space stays between 68 - 72 degrees all year long with no heat or AC. Sounds like you have a big project ahead of you, good luck and thanks for your comment.
I really like the white foam board. Who makes it, where did you buy it
The r21 is probably overkill with the foam board but as long as you have your air gap from bottom vent up to your rig cap you should be good.
Your going to notice a huge temp difference in that area.
Great job
They manufacture color coded builders spacers in mm increments that you can use to level the battens which might have made it easier the. Using random offcuts.
You are probably right but I already had the lumber left over from previous projects so it was an easy way to save some $$
Would have been worth it to use blown-in insulation (the packed in kind) between foam boards instead of fiberglass? I agree with you that the thermal bridging probably wasn't worth any additional effort. I wish I could find some foam board like yours.
The blown in would have been faster and maybe slightly higher R-Value but would have also been much more expensive. I prefer to do it by myself and my R Value is already plenty high. Thanks for watching.
Did you have air vent at the bottom? How is that going to work with less ventilation?
I think he said he was going to put in soffit vents later ?
Could be making a enclosed space attic? I would have spray foamed it.
You can always add another roofing layer on top with vertical battens under that for air flow.
radiant barrier (aluminum product) under or over (or suspended between double layer batten = best) the battens would help a lot with preventing a lot of the Sun's heat from ever reaching the insulation in the attic.
Air flow? No? Why?
There's tons of air flow. Look back at the first insulation video I posted and I talked about how I put a large airspace behind the insulation.
Why not spray foam it yourself?