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nash

can i insulate over paperback insulation or do i have to remove it.

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I have paper back insulation in my cabin and it is of low R valve.

I would like to insulate over the existing insulation without all the hassel of removing the old paper type. Could I simply make cuts in the paper to let it breathe or do i have to take it all out.

or do nothing . thanks

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18 minutes ago, nash said:

I have paper back insulation in my cabin and it is of low R valve.

I would like to insulate over the existing insulation without all the hassel of removing the old paper type. Could I simply make cuts in the paper to let it breathe or do i have to take it all out.

or do nothing . thanks

Best practices of several energy programs recommend removing vapor barrier(s) from between insulation layers so that moisture doesn't get trapped adjacent to building materials. Therefore it depends on where the "paper" is located. If it is in an attic and the paper is on top, it is incorrectly installed already and should be removed. If it's against the ceiling, it's fine. From the way your question is stated, I suspect the former is the case?

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Best practices of several energy programs recommend removing vapor barrier(s) from between insulation layers so that moisture doesn't get trapped adjacent to building materials. Therefore it depends on where the "paper" is located. If it is in an attic and the paper is on top, it is incorrectly installed already and should be removed. If it's against the ceiling, it's fine. From the way your question is stated, I suspect the former is the case?

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its a open ceiling cathedral framing. the paper is backed to the interior and done as a vapour barrier.  

but if i cut slits into to it then air can exchange and no moisture....am i right or wrong to think this.

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Slits will work, and the best vapor barrier is poly sealed with tape. In my climate, we are required by code to seal around electrical boxes with poly covers or use boxes with built-in gaskets. Keep indoor air out of the rafter cavities, and provide air circulation of the cavities and you will have no issues. Soffit vents and ridge vents.

You can form a bag around an electrical box from a square piece of 6 mil poly. Make it large enough to have several inches hanging all around the box. Tape around the wire. Then when you staple up the vapor barrier, cut a small hole and pull your bag edges out, trim and tape.

 

Edited by John Kogel

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