horizontal wall crack around perimeter of room

[Randall Clark]

Inspected a slab house today built in '89 and it had horizontal separation hairline cracks between pieces of sheetrock approximately 3' from floor level all the way around the first floor family room (exterior walls.) Largest gap was approximately 1/64'. House had several other thin cracks above windows and doors and tape separation at wall to ceiling junctions in several areas. Nothing too big but just a lot of them.

I've never seen horizontal cracking along three exterior walls. No signs of bowing and no significant foundation cracks. Any idea what is going on?

[Rick Cantrell]

Several things can cause that
Some I can think of are

Long periods of high humidity

Drywall screws were over driven
This will actually cause the drywall to be loose
Loose drywall will crack at the seams

Bad tape and mud job

There are likely many other causes, including foundation problems
High levels of moisture in the wall (EIFS)

[Kristi Silber]

This is a pretty good article about cracks in drywall (http://www.sbcindustry.com/images/technotes/T-GypsumInstallation09.pdf). Improper humidity/temperature control during installation is a strong possibility.

[Ian Page]

How high was the room? If 11' (approx) the horizontal crack, 3' off the floor is likely poor taping and mudding at a joint. Overall it sounds like a shoddy drywall and taping job, anyway. Cracks around/above windows and doors may because the drywall was pieced, rather than installing larger/full sheets and cutting out the opening once hung. The installer may also have missed studs with screws/nails or even failed to install each joint over a stud/nailing surface. Running a stud-finder over the cracks might have provided some enlightenment.

There could also be issues with the framing. Hard to tell without being there.

[Kristi Silber]

It seems significant that all the cracks are on exterior walls (isn't that correct?) I'm betting on expansion/contraction issues with the framing due to change in moisture content. Where are the cracks above ceilings and doors? Horizontal or vertical?

[Randall Clark]

It seems significant that all the cracks are on exterior walls (isn't that correct?) I'm betting on expansion/contraction issues with the framing due to change in moisture content. Where are the cracks above ceilings and doors? Horizontal or vertical?

Some cracks were horizontal, some vertical. Those were very thin in nature. House is a foreclosure and had been vacant for an unknown period of time. Also, the A/C did not cool properly so no telling how long that did not remove humidity.

[Joseph Peake]

Great article, Kristi. Thanks.

[Don Hester]

Kristi,
Good article. Thanks for sharing.

[H.G. Watson, Sr.]

The limited locations (exterior walls), bad continuous horizontal seam at 3' up on all walls, and occasional lifting at wall-ceiling junctions, seams and areas near windows, are suggestive of water infiltration problems on outside walls, collections of water and moisture issues at floor plates, and crap remediation work for problems due to same.

Its pretty SOP to R&R to 3' when the wall plates have been saturated and there has been wet insulation and/or mold/mildew issues on the drywall. Avoiding the FB & bracing which might be horizontal, staggered, or herringbone.

The crap workers don't pull together using blocking transition installed behind the exsisting and dropping down in the cavity to transition and support the seam between the pre-existing sheet and the replacement. Bad tape jobs and repairs elsewhere are also common. Whole job screwy if the area wasn't left open for sufficient time and dries out completely. If home unocupied and unconditioned - repair work won't dry/cure properly either.

I'd be looking for infiltration/repairs on the exterior, gutter/roof leaks, window leaks, finishing system or sheathing flashing, drainage, defects, checking fire reports, and clue reports, and checking the outlets in the repaired zone, as well as if the area is Wall-to-wall carpet, checking under the carpet and pad at the exterior walls & outside corners.

Another possiblity at 3' up is removal/replacement of a chair-rail moulding & other moldings elsewhere (carpentry trim) and/or panelized bead-board (nailed and/or glued directly upon prior gyp board?) or other decorative wall finish from the area (might have been poorly DIY installed and unattractive and was removed and refinished less-than-idealy).