Installing vapor barrier in corners and odd spaces

[Borrall Wonnell]

I'm stumped on how to "properly" install vapor barrier. I've got is a

10' roll (folded, actual roll dimension is 5'). Basement walls are 7.5' high but I need to run barrier up into the joist space to fully seal the area.

On a straight flat wall, no problems. When it comes to corners and other obstacles (joists, overhangs, etc.) I just can't do the plastic origami that seems to be required. I either end up having excessive folds in the plastic or I make an imprecise cut to get around the object. Either way, the job looks sloppy.

Adding to that, most local installations make use of acoustical sealant around the perimeter of the barrier...given my current trial/ error approach, that's going to get very messy.

The alternative I've considered is to cut my pieces to size for the plain wall sections, then cut additional strips to work around the irregular areas. This will result in many extra seams (and potential failure points).

Any pointers would be greatly appreciated.

[Sonny]

Whether you are using plastic (moisture barrier), paper (gift wrap), fabric (upholstery) or any other material and it doesn't matter if a corner is an inside or outside corner, what you are doing is negotiating a corner, i.e., a miter (fold in your case), either inside or outside. In some cases, you have to cut along a vector, to relieve one folded flap, in order to be continuous with/to the following fold (mitered area).

The concept you have to keep in mind is you are essentially dealing with miters. Don't try to make the corners conform to the plastic, make the plastic conform to the miter concept.

Sonny

[hrhofmann]

Be sure to tape the seams also, as moisture can work thru small openings.

[Joe]

If your significant other does all the gift wrapping in your house, have her show you how it is done. Most women have a knack for this that many males (even me) lack. Don't fret about sealing seams; the sealing tape is really tough stuff and chances of failure are very low. Having a two people operation is very helpful.

Joe Joe