A free tool, for any surface
Can I paint
over it?
Most peeling paint is not bad paint. It is the right paint on the wrong thing. Tell us what is on the surface and what you want to put on it, and we will tell you whether it works and how to prepare.
Seventy two combinations, written the way we would explain them on site.
Two questions
What is on there,
and what do you want on it?
Yes, this is the most common job we do
Water based paint over old oil is fine if the oil is keyed and primed. Skip that and it peels off like a sticker within months.
- 1Do the tape test on a small area first. If old paint lifts, it has to come off before anything goes on.
- 2Wash down with sugar soap and rinse with clean water. Paint does not stick to grease, nicotine or kitchen film.
- 3Sand the whole surface until the shine has gone, with 120 to 180 grit. You are scratching it, not removing it.
- 4Dust off and wipe with a barely damp cloth. Let it dry.
- 5Use a primer undercoat that states it goes over oil based paint.
- 6Two full finish coats. One coat is not a finish.
This is general guidance for sound surfaces. Always read the tin, and test a small area before committing to a room.
Not sure what you have? Send us a photoFive minutes, a bit of cotton wool
Four tests
before you buy paint.
- Oil or water based?
The meths test
Soak cotton wool in methylated spirits or acetone free nail varnish remover. Rub hard on a hidden spot for thirty seconds.
If paint comes off on the cotton wool or the surface goes soft, it is water based. If nothing happens, it is oil.
- Distemper or limewash?
The damp finger test
Wet a finger or sponge and rub a small patch.
If colour comes away like chalk, it is distemper inside or limewash outside. Neither will take modern paint.
- Is the old paint sound?
The tape test
Score a small grid into the paint with a knife. Press on a strip of masking tape, rub it down and pull it off sharply.
If flakes come off with the tape, the existing paint is failing and must be removed, whatever goes on next.
- Safe to sand?
The lead test
In any house built before 1970, use a lead test swab from a hardware shop on each layer you will disturb.
If it turns colour, do not dry sand, burn or power sand. Use wet abrading or a stripper, or call someone set up for it.
Asked on site
About
painting over things.
- Can I paint water based satin over oil gloss?
- Yes, but only after washing, sanding until the shine has gone and using a primer undercoat that says it goes over oil. Without that key it peels off in strips, often within a few months.
- Why is my new emulsion cracking on the ceiling?
- In an older house the most likely reason is distemper underneath. The water in the emulsion softens the chalky layer and it lets go. The fix is to wash the distemper off completely or seal it with a stabilising solution before repainting.
- Can I use masonry paint on lime harling?
- We would not. Acrylic masonry paint traps moisture in lime walls. It looks good for a few years, then blows off and often takes the harling with it. Limewash or a breathable mineral paint is the right finish.
- Do I always need a primer?
- Not when painting like over like on a sound surface. You do need one on bare timber, new plaster, anything shiny you are changing system on, and anywhere stains or knots could bleed through.
Would rather not risk it
We can tell you
in one visit.
If the old paint is failing, the house is old or the surface is one you care about, a quick look saves a lot of stripping later.
One repair tip in every letter, from real jobs.