· by Michael Blair, Nashville's Drywall Repair
Round bumps along a stud line and hairline cracks along seams are the two most common drywall complaints, and both come from timber moving behind a board that does not.
Why nail pops happen
Framing lumber dries and shrinks after installation, and Middle Tennessee humidity swings make it move seasonally afterwards. The fastener stays where it is while the timber moves away, pushing the compound off the head.
They are most common in the first year or two of a house and after a particularly dry winter.
Fixing them properly
Drive a screw an inch or two away from the pop into the stud to pull the board tight, then remove or re-set the original fastener, then fill and feather.
Simply filling over a pop without re-fastening means it returns, because the board is still loose.
- Re-fasten with a screw nearby before filling
- Remove or set the original fastener below the surface
- Three thin coats, each wider than the last
- Prime the repair before painting
- Expect a few in the first years of any house
Seam cracks
Hairline cracking along a taped seam is movement at the joint. It is usually cosmetic and recurs if simply filled, because the movement continues.
The durable repair cuts out the failed tape, re-tapes with mesh or paper and compound, and feathers wide.
When it is more than movement
Cracks radiating diagonally from the corners of doors and windows, cracks that keep widening, or cracking accompanied by sticking doors and sloping floors.
Those point at structural movement rather than drywall, and repairing the surface without investigating means doing it again.