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1989 house with inconsistent poly behind drywall. Why…?

Chris D | Posted in General Questions on

Some daily randomness for the pro builders:

CZ3 house from 1989, custom-ish home.

Tore apart a bathroom a few years ago.  No poly anywhere.  Not unusual for a bathroom.

Took the baseboards and window sills off one bedroom to do normal spit-and-polish stuff before painting.  Poly visible at the sill plate from behind the drywall, poly visible behind the drywall at the window sill (10 inches above subfloor).  Didn’t think much of it at the time, and can’t easily explore anywhere higher without re-painting (it’s the wife’s pandemic office).

Adjacent bedroom is a storage room at the moment.  Made a small exploratory hole in the drywall to expose the header/stud config above the windows.  Then I realized there was no poly.

This leads me to believe there is poly in one room and not the next room, or the rooms only have poly at the bottom of the walls.  Not enough data yet, I know.

Any reason why a house would be built like this?  Builder ran out of poly?  I would expect more of an all-or-nothing approach to poly installation, obviously.

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  1. Expert Member
    Zephyr7 | | #1

    My guess is that the room was renovated at some point in the past, and poly was added as part of that renovation. It's difficult to be sure though. You could check for date stamps on electrical wire and lumber and see if there are differences between the "with poly" and "without poly" areas. If you see big differences in years, then you can be reasonably sure there was a renovation sometime around the more recent date stamp years.


    1. Chris D | | #2

      That was my only other theory, if there was a reason to gut and re-hang that one room. So strange.

      I'll have to pull off the window sills in a few other rooms and see if a pattern emerges, and which room is the outlier. Half of the contractors in our area of NC seem to be from NY/NJ (can't hide that accent), so it was probably someone doing things the Northern way.

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