Too many decorators are still using cheap contract matt to prime bare plaster. It’s an old-school approach and you shouldn’t do it in modern decorating. There’s no need.
I see it all the time on the Decorators Forum UK. People arguing that, “contract matt allows plaster to breathe”. Well yes, it does, until you coat over the top of it with something that doesn’t. So that argument is null and void.
Or another one I see is, “you don’t prime plaster with a paint full of vinyl because it creates a film”. A film? A vinyl or durable matt will adhere to bare plaster better than it will a contract matt. You’re literally giving the paint less chance of sticking.
The best one, “it’s cheaper than vinyl matt so you’re saving money”. Absolute poppycock!! If I’m using a vinyl matt and I’m faced with bare plaster, I give it 2 coats of vinyl matt. You give it a coat of contract matt and then 2 coats of vinyl matt. How is your way cheaper??
The Right Way to Mist Coat Bare Plaster
For the love of God, follow the manufacturer’s instructions!! They are there for a reason and no decorator is qualified enough to know better than the scientists who make the paint. Every vinyl matt I know of tells you to use a diluted vinyl matt to mist. With the exception of Tikkurila Optiva 5 and Farrow and Ball Modern emulsion, every durable matt I know of tells you to use durable matt as a mist coat. Even acrylic eggshells are the same!
Paint sticks better to bare plaster than it does a cheap chalky contract matt. The contract matt is your weak link. I don’t understand why decorators still want to use the stuff. The only time it is ok to use contract matt is when you’re house bashing.
Some decorators are stuck in their ways and will carry on using contract matt as a mist coat. It doesn’t matter what I tell them, or what it says on the tin of paint. All you hear is “I’ve been doing it this way for x amount of years and never had a problem”, or “this is how I was taught in collage”.
However, using contract matt does cause issues. Maybe not straight away, but over time you’ll get flaking. Paint has changed, so the way we decorate needs to change too.
What is contract Matt paint used for?
Contract matt is generally used as a “builders finish” on new build houses. This is for a few reasons;
You can use it on plaster that isn’t fully dry.
Contract matt is easy to touch up, or “patch” if other trades damage the walls.
But mostly because it’s cheap. Contract matt is less than half the price of vinyl matt, so a contractor is saving around £400 on materials throughout the house.
Can you use contract matt on new plaster?
You can use contract matt on new plaster, but as the blog above explains, you should not use it as a primer before applying different types of paint.
What’s the difference between vinyl Matt and contract Matt?
The difference between vinyl matt and contract matt is the “vinyl”. This is a polymer resin that is added to paint to bind all the other materials. Vinyl matt contains more polymer binder than contract matt, meaning it is more durable and less porous.
Do Not Use Contract Matt as a Mist Coat on Bare Plaster – by Mike Cupit