[Joe F]

I have paper faced insulation in the attic that has some tears in the paper. I'm going to replace the sections that are real bad, but in the areas that just have small tears, I want to tape it up. Is there a proper type of tape for this?

 

[GottaFixIt]

I'd use DOW weathermate.

 

[Bud9051]

Hi Joe,
Where is the insulation that you can access the facing? In the attic floor the paper should be under the insulation next to the drywall.

Bud

 

[Joe F]

The insulation is directly under the roof decking. House is a colonial built in '43 with a walk up attic.

 

[Bud9051]

That sounds like a touchy area to have insulation with just kraft paper to the inside. I'll list some concerns, remember I'm a thousand miles away.
1. There needs to be an air gap above the insulation and not have it in contact with the roof.
2. There needs to be a rigid air barrier covering it, like a layer of drywall. That keeps attic air and moisture from getting through.
3. You need to go one way or the other, insulate and air seal the attic floor or insulate and air seal the bottom of the rafters along with the gable ends. In DC a vapor barrier is another discussion.
4. If the ceiling is also insulated you run the risk of a cold attic and condensation on that rafter insulation and air barrier.
What is in place for attic venting; soffit? Gable? Ridge? Other?

Bud

 

[Joe F]

As far as I can tell, there is no air gap between the insulation and the roof. The only rigid air barrier that has ever been there is a some thin luan paneling. Probably been in place since the early seventies. The attic is unvented save two small windows at each end.

I understand the concerns, but the existing insulation has worked for 73 years with no mold or moisture issues. All I'm looking to do is restore the integrity of what's there. That said, I'm not opposed to doing more, but I'd need more convincing since I have a functioning system with no evidence of a problem anywhere.

 

[Gary in WA]

I agree, leave the paper facing alone as it is acting as a wind baffle to direct the air stream along the roof because I really doubt it is close after 10 years or so. FG, faced insulation sags to compress itself from 5-1/2" to 3" in a crawlspace, I can't see a steep roof being much different. NO NEED to tape the seams/joints as it is area weighed, not your air barrier, though the insulation may help keep the attic cooler in summer from roof solar gain. The facing is a vapor barrier (retarder) and should have gaps between pieces to allow moisture in attic center/edges to leave via the roof plane where most of your air movement is located. eg; when installing a radiant barrier, always leave a gap top/bottom for same reason. Don't tape it...

Gary
PS. even if they stapled the tabs to the rafter tops, it will stretch/sag to create a gap, at least in the center of the facing. IMO.