Which is better? You decide!

Here are a couple pics from a job we recently did.

On the left of the house is a cathedral ceiling with R-38 fiberglass insulation.

On the right side is an attic area with 2" of closed cell foam R-14.

There is NO additional insulation anywhere in the attic side (nothing in the floor, just empty joists bays)

The GC was going to add an R-30 fiberglass batt. Think it's necessary?


Tim

the right side appears to be leaking less heat, but the problem is that someone will eventually have to go up and scrape the snow off

bob

rsanter said:

, but the problem is that someone will eventually have to go up and scrape the snow off

bob

Click to expand...

Why ?
There's is certainly no load danger with that little dusting. Add another 2 feet of wet snow and then it might need to be shoveled off.

If theres a drawback to closed cell spray foam (which is just about the greatest thing going) it's adding batts to boost the R value. I know I may only be talking about where I am but you'd have to vapor barrier the batts to keep the house moisture out but then you've created vapor lock with the spray foam. I'd top the existing 2 inches of foam with another 2 inches of spray foam. It is what it is, R14 is a little thin for walls but not enough for a roof.

Great pics. Foam really works, fiberglass alone, not so much

I am going through the fiberglass batting vs. cellulose vs. foam currently (bonus room slopes). Those pics sure are testimony, but can I ask if there was any venting between the fiberglass bats and the roof sheathing on the left side? How about a vapor barrier?

Is there an insulated wall between the 2 areas all the way to the sheathing? The reason I ask is that the area on the right is conditioned(I believe this is the correct terminology)space so it is warm up to the bottom of the foam, if there is an airspace above the cathedral ceiling that is still attached to the conditioned space on the right then the heated air in the right hand attic is moving over into the area above the fiberglass and heating up the roof. I'm assuming when you say cathedral ceiling that they used scissors trusses, which still can flow air across, if solid rafters were used in the cathedral ceiling this would be a moot point.

Also are both rooms held to the same temperature inside?