Drywall damage is one of the most common home repair issues, and most homeowners can handle small fixes with a putty knife and a can of compound. But some drywall problems are symptoms of bigger issues — and knowing the difference saves money.
Hairline cracks in the corners of doors and windows are normal and cosmetic — the house is shifting seasonally. A skim of caulk and touch-up paint handles it. But diagonal cracks running two feet or more, especially near a supporting wall, can indicate settlement and are worth a professional look.
Nail pops are easy: back the drywall screw out slightly, drive a new screw an inch above or below, and skim over both. Widespread nail pops through a whole ceiling, though, can mean the framing wasn't properly fastened — worth investigating.
Water stains are never cosmetic. They mean water reached your drywall from somewhere. Fix the source (plumbing leak, roof leak, ice dam, window flashing) before you patch, or you'll patch the same spot every winter.
Holes larger than a fist need a backing patch or California patch, taped and mudded with three coats. If you're comfortable with a taping knife, you can do it. If you have textured walls or ceilings, matching the texture invisibly is where pros earn their fee.