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.

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

On Dec 31, 11:24*am, Sonny wrote:
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

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

On Dec 31, 10:40*am, Borrall Wonnell wrote:
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.

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