Most paint failures start before the first coat goes on. The surface was dirty, glossy, damp or loose, and the new paint could not grip. Prep is the larger part of a good paint job, and in Boston's older homes it is where most of the hours go.
Do I need to prime before painting?
You need primer on bare wood, bare plaster, new drywall, patches, stains, glossy or oil-based paint and big color changes. You do not need a full coat of primer on clean, sound, flat paint of a similar color. Primer does three jobs: it seals, it bonds and it blocks stains. If none of those is needed, two coats of good paint are enough.
Can you paint over old paint if it is in good shape?
Yes. You can paint over old paint that is clean, dull and firmly attached, and no primer is needed. Wash it, fill the holes, sand any shine off and paint. The test is simple. Press tape on the wall and pull it off fast. If paint comes off with it, the old paint has to be scraped and primed first.
Do I need to sand the walls before painting?
Walls need a light sand in most cases, and a full sand only when they are glossy or rough. A quick pass with a pole sander knocks down dust nibs and old roller lint and gives the new paint a key. Trim with a gloss finish always needs sanding. In a house built before 1978 the old layers may contain lead, so sanding follows lead-safe rules and is never done dry with a power sander.
Do painters fix nail holes, cracks and dents first?
Yes. Filling nail holes, small cracks and dents is part of normal prep and is in our quotes. Larger work is listed separately: wide plaster cracks, loose plaster, holes bigger than a fist and failed ceiling tape. Plaster cracks in old Boston houses often return if they are only filled, so they are taped or opened up and repaired properly.
How do I paint over a water stain so it does not bleed through?
Seal the water stain with a stain-blocking primer before painting. Wall paint alone will not hold it back, and the brown ring comes through again in days. Make sure the leak is fixed and the area is dry first. Ice dams are a common cause of ceiling stains here in winter, so check the roof edge above.
Can you paint over smoke stains or pet smells?
Yes, with the right primer. Smoke and nicotine are washed off as far as possible, then sealed with an odor and stain-blocking primer before the finish coats. Painted over without sealing, yellow stains and the smell both come back. Pet smells in walls and trim are sealed the same way, but smell in a subfloor needs treatment there, not on the walls.
Mold on the bathroom ceiling: can it just be painted over?
No. Mold painted over grows back through the new paint. Surface mildew is killed and washed off, the ceiling is left to dry, a stain-blocking primer goes on and then a paint made for bathrooms. The cause has to change too, which usually means a working fan run long enough after showers. Mold that covers a large area or keeps returning points to a leak. HomeGuide puts professional mold work on a small area at $500 to $1,500.
Paint is peeling to bare wood on my old house. What prep does it need?
Where paint has peeled to bare wood, the loose paint is scraped off, the edges are sanded smooth, the bare wood is primed and gaps are caulked before two finish coats. Wood that has gone grey is sanded back to fresh wood, because primer does not hold on weathered fibers. On a house from before 1978 this is lead-safe work under Massachusetts rules, with the ground covered and the chips collected.
Why is my paint peeling?
Paint is peeling because it lost its grip, and water is the usual reason. Outside, water gets behind the paint from open joints, leaking gutters or damp coming through the wall from inside. Inside, it is steam, a leak or paint put over a dirty or glossy surface. Freeze and thaw make it worse here, because water in the wood expands each time it freezes.
Why is paint bubbling or peeling in my kitchen or bathroom?
Paint bubbles and blisters in kitchens and bathrooms because of moisture and grease. Steam gets behind a weak paint film and lifts it. Cooking grease stops new paint from bonding. The fix is to scrape and sand the failed areas, wash the walls with a degreaser, prime, and use a paint made for damp rooms. A fan that vents outside matters as much as the paint.
How do I know if old paint is oil or latex, and can latex go over oil?
Rub the paint with a rag wet with rubbing alcohol. If color comes off, it is latex. If nothing comes off, it is oil-based. Latex can go over oil-based paint only after the surface is sanded dull and coated with a bonding primer. Without that, the new paint peels off in sheets. Old trim and doors in Boston homes are very often oil-based.
Do bare drywall patches need primer?
Yes. Every drywall patch needs primer before paint. Joint compound soaks up paint differently from the wall around it, so an unprimed patch shows as a dull spot from the side. Spot prime each patch, then paint the whole wall from corner to corner.
A free estimate with a written quote is the only way to get a real price for your job. Call or text (617) 553-6484.