Sealing Vapor Barrier in Ceiling

[71blackcheyenne]

Having some guys poly, tin, and insulate my shop ceiling, they are putting up a 6mil poly vapor barrier, and they are tuck taping around light boxes, but not the seams. Contractor told me its not code to tape ceiling seams, only wall seams. Is he givin me the runaround or telling me the truth?

 

[1953mercury]

Re: Sealing Vapor Barrier in Ceiling ...

Are you talking about taping the plastic or the sheet rock? The plastic should overlap and fire taping is only required on a wall that is shared with a dwelling space and should be 5/8" as opposed to 1/2" rock. Mike

 

[jvitez]

Runaround!! What is the point of installing a vapour barrier if it's not completely sealed? Yes, ceiling 6 mil poly edges need to be sealed. There are 2 ways to do it:

1. Staple the poly with at least a few inches of overlap, and Tuck tape the seam.

2. Overlap the poly by one joist or stud space, run a bead of acoustical sealant along the one-over stud, and staple into the acoutical sealant bead.

Both are acceptable. Just leaving it flopping on top of each other is not correct!

 

[Tim The Tool Man]

Runaround!!

X2

How much extra work is it to tape the ceiling seams? If he is giving you stress then just do it yourself and be done with it.

 

[71blackcheyenne]

Thats what I figured, told him he's full of it and to tape damn seams for the time it takes, in the past i've heard some of the old fellas say it was a good thing to let a little heat into the attic, but that was the old days lol. My cousin is a journeyman carpenter and i told him about this guy, he just laughed. Would have rather done the whole job myself, but spare time is always an issue.