Short answer: if your Columbia home was built before about 1950, its walls are probably three coats of plaster over wood lath, not drywall. Plaster cracks as its keys break and it separates from the lath; it can be re-anchored, patched with setting-type compound and skim-coated so it lasts another fifty years. Drywall compound alone won't bond to lath, which is why quick patches on plaster fail. Keeping plaster is almost always cheaper and better than gutting to drywall.
Tap the wall in a 1920s bungalow on Westmount or a foursquare in Benton-Stephens and it sounds solid and dense — nothing like the hollow tap of drywall. That’s plaster: a lime or gypsum base coat pressed through gaps between thin wood laths so it “keys” behind them, a second coat to build thickness, and a thin finish coat troweled smooth. It’s heavier, quieter and more fire-resistant than drywall, and it’s why those houses feel the way they do.
It also has a hundred years on it.
Where plaster lives around Columbia
- Columbia: the Old Southwest, West Broadway, Benton-Stephens, East Campus, North Central and the blocks around downtown — most homes built before 1950, and many into the early 1950s.
- Jefferson City: Old Town, the East End and the streets around the Capitol.
- Boonville and Rocheport: nearly every building in the historic districts.
- Fulton and Centralia: the older homes near the courthouse squares and the colleges.
Anything built after the late 1950s is almost certainly drywall.
Why plaster cracks, bulges and falls
Broken keys. The plaster that squeezed through the lath and hardened behind it is what holds the wall on. A century of vibration, settling and moisture breaks those keys, and the plaster starts to separate from the lath. You feel it as a hollow, springy spot; you see it as a bulge or a network of cracks.
House movement. The same clay soil and seasonal humidity that crack drywall (here’s why) crack plaster — but plaster is brittle, so instead of one line at a joint you get “map cracks” spreading across a wall.
Water. Old roofs, radiator leaks and bathroom plumbing turn plaster soft and crumbly. Once the gypsum has been wet, that section is done.
Bad previous repairs. Drywall compound smeared into a plaster crack doesn’t bond to the lath and moves differently from the plaster around it. It cracks again along the same line, often within a year.
Sagging ceilings. The most urgent plaster problem: a ceiling that has lost its keys and is hanging on the lath by habit. If a plaster ceiling has a visible sag or drops chunks, stop and call — it will come down on its own eventually.
How plaster is repaired properly
- Stabilize. Loose plaster is reattached to the lath with plaster washers and screws, or with an injected adhesive for larger areas. Anything that can’t be saved is removed back to sound material.
- Rebuild. Holes are filled with a setting-type base compound that hardens chemically and keys into the lath. Cracks are opened, filled and bridged with fiberglass mesh so they stay closed. Missing sections get drywall shimmed flush to the plaster surface.
- Skim and finish. The repair is skim-coated in thin coats and sanded so it reads as one continuous surface, then primed. Smooth is standard; a historic sand or swirl finish can be matched.
A repair done that way holds. A repair done with a tub of pre-mixed drywall compound and a putty knife doesn’t.
Keep the plaster or go to drywall?
Keep it, almost always. Repair is cheaper than demolition and re-drywalling a room, you avoid a dumpster full of plaster and lath and a week of dust, and you keep the density, sound-deadening and character of the original walls. Replacement makes sense only when large areas have lost their keys or been soaked, or when the wall is being opened up anyway for a remodel — and even then, the transition between new drywall and old plaster has to be blended so there’s no step.
Questions about plaster walls
Can plaster walls be repaired, or do they need to be replaced with drywall? Most plaster walls can be repaired. Loose plaster can be re-anchored to the lath and cracks bridged so they stay closed. Replacement only makes sense when large areas have lost their key or been soaked.
Why did my previous plaster patch crack again? Plaster and drywall compound move differently, and a compound-only patch never bonds to the lath. A lasting repair uses setting-type compound keyed into the lath and mesh over cracks.
How much does plaster repair cost in Columbia? Most plaster crack and hole repairs run $175–$550 — a bit more than the equivalent drywall repair because of the anchoring and skim work. Larger stabilization is quoted after a free look. See the cost guide.
Can you hang a TV or shelves on plaster? Yes, but anchor into the studs, not the plaster — toggle bolts and plastic anchors crumble plaster around the hole. When it’s time to remove them, the holes are repaired the same way as any other plaster hole.
Is there lead paint or asbestos in old plaster? Plaster itself rarely contains asbestos, but paint on pre-1978 walls may contain lead. We sand minimally and use dust control; if you’re planning heavier work on painted plaster, a lead test is cheap and worth doing.
Cracked or loose plaster? See plaster repair or text photos to (913) 375-8472.