As others have said, it's vapor-permeable wind-barrier
wrap -- the same basic material as those envelopes that
you can't tear; also used often for bank card covers.
I wonder about it in the very long term. What if it breaks
down over years? (I wonder the same about flakeboard
sheathing.) But in general it's a good solution. With the outer
wall breathing and plastic vapor barrier under the drywall
on the inside, moisture stays inside, providing for better
air quality on warm winter days. I have a brother who built
his own house that way in the 80s, using 6" studs for better
insulation. He heats it (in NH) with only a wood stove. There
are no drafts. The down side is also that there are no drafts. :)
One needs to open the windows a bit to get fresh air because
the house is super-sealed, essentially a plastic bubble.
Tar paper is fine, but doesn't breathe as well. House wrap
solves the problem created by interior use of plastic vapor
barrier. In older houses, vapor freely moves through the walls,
but if you seal the interior with plastic sheet you need a way
to let moisture in the wall get out.
| This is about that plastic wrapping they use to cover the exterior of a
| house under the siding. (Not a house that plays Rap Music) :)
| Anyhow, it seems that every new house built, and every house that gets
| new siding, is covered with this plastic wrap. Then, they use a wide
| tape, and apply the tape around doors and windows. The end result is a
| home that is similar to living inside a huge plastic bag.
| First, I have wondered if the people living in these houses are getting
| enough oxygen to breathe, particularly if they are retired older people
| who dont go out much.
| Second, doesn't all the moisture inside the house get trapped in the
| walls, which will cause the wood to rot? (And most new homes are built
| with chip board, which does not hold up well in moist conditions).
| Somehow, I dont agree with the use of this material, and would not use
| it on my own home, if I was going to build a new house or reside (which
| I am not planning to do either).
| Years ago, they applied tar paper, which was a paper coated with tar.
| That would shed any water that got beneath the siding, but still allowed
| for ventilation. To me, that made more sense, and it worked pretty
| well. It was not taped around doors and windows, but was often left so
| the door or window frame would overlap it, and form a tight seal.