By Exodus Home. Published
Why plaster is different
Many older homes in Cleveland and Akron were built with plaster walls over wood or metal lath. Plaster is hard and dense, and it often carries many layers of old paint. It also moves with the house over the years, which shows up as hairline cracks, larger cracks at corners and doorways, and areas where the plaster has loosened from the lath.
Paint does not fix any of that. It only shows it more clearly. Good results on plaster come from finding the problems first and repairing them before finish coats.
Read the cracks
Hairline cracks are common and usually cosmetic. Cracks that come back in the same place, or that run from the corners of doors and windows, are often from movement. A wall that sounds hollow or flexes when pressed may have plaster that has separated from the lath behind it.
Loose plaster needs to be secured or the damaged area replaced before painting. Painting over it can hide the problem for a while, but the crack usually returns.
Patching plaster
Small cracks are opened slightly, cleaned and filled. Larger cracks are often taped or reinforced so they are less likely to telegraph back through the paint. Holes and gouges are filled in layers, allowed to dry and sanded smooth. Edges are feathered so the patch blends into the wall around it.
Old anchors, nails and picture hooks can be pulled and filled at the same time, if you do not plan to rehang things in the same spots.
Primer matters
Patch compound absorbs paint differently than painted plaster. Without primer, patches can show through the finish as dull spots, a problem painters call flashing. Spot priming repairs before finish coats keeps the sheen even.
Older surfaces may also need a bonding primer, especially where earlier coats were glossy or where oil-based paint was used in the past. A simple test can show whether the old paint is oil or latex, and the primer is chosen to match.
Older homes and lead paint
Homes built before 1978 may have lead-based paint under newer layers. Any plan to sand, scrape or cut into old painted plaster should start with testing.
Pick a forgiving sheen
Even well repaired plaster has some texture. Flat or eggshell finishes hide small irregularities better than satin or semi-gloss. If you prefer a higher sheen on a plaster wall, plan for more prep.
Ceilings and tall plaster walls
Plaster ceilings deserve the same attention as walls. Sagging areas, stains from old leaks and cracks that run across the room are worth pointing out at the walkthrough. Stains are usually sealed with a stain-blocking primer so they do not bleed through the new finish. In stairwells and two-story rooms, repairs on tall walls need ladders and planks set up safely, so they belong in the plan from the start rather than added once the crew is in place.
What to expect from us
At the walkthrough we look at the cracks and test suspect areas by hand. We review the repairs, primer and finish with you. If we find more damage once work starts, we tell you before we go further. You walk each room with the crew lead at the end, and we finish what you find.