On Friday, January 10, 2014 1:59:05 PM UTC-5, dadiOH wrote:
wrote in message
If you don't want to actually *fix* it by re-taping,
use acrylic caulk...rub
in with finger, paint when dry.
Retaping it doesn't always work and it's a lot more work.
In a house there is always going to be some amount of
movement, especially over temp and humidity variations.
I'm sure if you kept a house a 70F year round, it would
eliminate a lot of these problems. But if it sees temp
swings from 50F to 85F, I think that can certainly
contribute to cracks.
I suppose t could but IME it doesn't. If it was a major factor, most of the
houses in the US (Canada too) would have lots of cracks.
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Don't they? Every house I've ever lived in had some drywall cracks
somewhere.
Just becaus you have something
taped, doesn't mean that it can't crack again. It depends
on the forces involved. Even taped, it can't withstand
much lateral movement.
True. But the DW itself isn't moving.
Why not? All materials expand/contract with temp, humidity,
etc. There is bound to be some movement. If you measured a piece
of wood, drywall etc, do you think the dimensions are going to
be exactly the same across all temps and humidity? Even a simple
wood door can swell up when it's very humid so that it won't close
properly.
Oh, OK, if a sinkhole opens up under
your house the DW is going to move 
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I was aware of the idea of using caulk and was thinking of
doing that. But a spray on product sounds like an even
better idea. Since making the post, I see Goof makes a
product like that designed for cracks.
I'd still use caulk, easy to put just where you want it; not so with spray.
___________________
I don't have vast experience with drywalled walls. Many of the places I
lived pre-dated drywall. The major ones that had/have it were my offices
and condo. Both used steel studs, neither ever had a DW crack during the 17
years I occupied them.
The last is my current house; I contracted it and have lived in it for 18
years. There has never been a crack in either a long or butt seam save
three on narrow (12" or less) pieces. Those three had been poorly
taped/fastened.
The one place I had a bigger problem was on a couple of corners. The metal
corner beads are nailed/screwed to the face of the studs as opposed to the
edges for long/butt seams; wider surface = more movement. A couple of them
developed hairline cracks where the corner metal laps the DW. Makers of
paper faced metal beads attribute that to the metal bead moving slightly
with the stud. So why didn't long/butt seams crack? Two reasons I can
think of...
1. As stated previously, the corner bead cracks were where the bead was
attached to the FACE of the stud and the face is wider, therefore move more.
2. IMO, the primary reason is that although the long/butt seams are
attached to the edge of the studs the tape is attached ONLY to the DW which
means that any expansion/contraction of the stud would affect only the DW
itself AND that effect would be evidenced by slight enlargement of the
nail/screw holes in the DW and/or the wood.
--
dadiOH
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