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Discussion Starter #1
I have a 22 year old home that has various insulation problems in the attic. Here's a quick rundown of the types of problems I'm seeing, numbered for reference:

1. Gaps at the top edges of wall insulation:





2. Gaps underneath the edge of our cathedral ceiling:



3. Gaps where pipes block part of a wall cavity:



4. Gaps around outlets:



5. Areas where the ceiling height changes. In the attic, these look like popups with blown in insulation on top. The problem is that the insulation tends to fall off on the edges, leaving little coverage there:





6. Similar to problem #5, we also have tray ceiling popups where insulation tends to fall off on the sides (here includes an inside shot of the tray ceiling):







For problems 1, 2, 3 and 4, what's the best fix? Spray foam? Stuff more bat insulation in the gaps?

For problems 5 and 6, and ideas for keeping the blow in insulation in place around the edges of raised ceilings?

Input appreciated!
 

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Got some interesting issues going on there.
Where's the baffles to keep that insulation from falling down the walls?
Why did someone bother insulating a gable wall?
Any fixtures, plumbing, wiring penatrations should have been air sealed before insulation.
 

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Discussion Starter #7 (Edited)
Got some interesting issues going on there.
Where's the baffles to keep that insulation from falling down the walls?
Why did someone bother insulating a gable wall?
Any fixtures, plumbing, wiring penatrations should have been air sealed before insulation.
It's actually a cathedral ceiling room on the other side of the wall in the first few pics, not a gable. Any pointers on the other things? Where are you seeing baffles needed?
 

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Discussion Starter #9

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MEASURE ONCE, CUT TWICE
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That doc is filled with great info - thanks much!

It actually doesn't address the two general problems I'm having though. For problem 1, where I have gaps around my bat insulation, should I stuff in more bat or spray foam?

For problems 5 and 6, how should I keep insulation around an elevated popup from falling off at the edges?

You could use some thin plywood to make a dam that sicks up and then fill with loose insulation. Use bats on the vertical sides.

Gaps can be filled with pieces of bat insulation. Spray foam will push the insulation away and may leave gaps at a different location. Don't pack it too tight or it won't insulate.
 

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Pull the batts back and "re-align" them after you spray foam the gaps.

We usually use rigid foam to create end dams but that is because it is what we have up there. Pugsy is right about the think plywood working just the same.

Only benefits for rigid foam are in situations where the foam also creates a thermal break on what it is being bonded to.
 

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DOH!

Of course, foam boards are better.

Thanks WoW
Not always boss man. The reality is that if its over an area that is already insulated, plywood is much better about holding up long term.

Foam just make sense where you can kill two birds with one stone.

Also easier to cut up in the attic with a utility knife vs. saw.
 
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