What is contract emulsion, and is ceiling paint any different?

The names on trade tins describe a role in a sequence, not a quality level, and that is why buying by name goes wrong. Contract matt exists because a builder needs to get colour on a whole plot cheaply and needs the next trade to be able to paint over it. It is genuinely the right product for that job and genuinely the wrong product to leave on a hallway wall for ten years.

Step by step

1. Know what makes contract emulsion different.It has a low binder-to-pigment ratio. That makes it cheap, very high in opacity, quick-drying, matt to the point of being dead flat, and highly porous — which is exactly what you want under another coat, and exactly what you do not want as a finish.
2. Use it where it belongs.As the mist coat and build coats on new plaster and new plasterboard, on ceilings in rooms nobody touches, in lofts, garages and cupboards, and as a cheap way to get a whole new-build shell one colour before the proper finish goes on.
3. Do not leave it as the finish in a lived-in room.It marks if you look at it, cannot be washed without burnishing or removing colour, and chalks off on hands and furniture. This is the single most common reason a new-build owner finds their walls rub off.
4. Treat trade ceiling paint as the same family.Most ceiling paints are a contract or trade matt with high opacity, a flat finish and often a longer wet-edge time so a big ceiling can be rolled without lapping. Some are tinted faintly so you can see where you have been. That is the whole difference.
5. Check whether your ceiling paint is actually different.The exceptions worth paying for are genuinely different products: a bathroom or kitchen ceiling paint with a mould inhibitor and a more moisture-tolerant film, and a stain-blocking ceiling paint. Read the tin for what it claims to resist, not for the word 'ceiling'.
6. Overcoat contract matt with the finish you actually want.It takes emulsion readily because it is porous. Two coats of a durable matt or soft sheen over sound contract matt gives you a proper finish without stripping anything — this is the standard fix for a new-build.

Tips

• Contract matt's porosity is why the second coat of your finish paint often looks so much better than the first: the first is partly soaking in.
• If a builder's spec says 'two coats emulsion', ask which emulsion. Two coats of contract matt is not a decorated house.
• It is the cheapest way to see a room in a colour before you commit — a rough coat on the wall tells you far more than a tester card.

Common mistakes

• Buying trade contract matt because it is cheaper per litre — It is cheaper because it contains less binder. On a wall you touch, you are buying a surface that will need redoing rather than washing.
• Assuming ceiling paint is a technically different product — In most cases it is a high-opacity flat matt. Believing it has special properties leads people to use it in bathrooms where it fails quickly.

Questions people ask