So, appropriately enough I’m typing this while I’m waiting for paint to dry! I knew today’s was only going to be a very small job, and that there would inevitably be some “down time” between coats of paint, so I brought my laptop with me so I could put the time to good use.
The answer to the question “how long should you wait between coats of paint” is actually incredibly simple; read what it says on the tin! Almost all paint tins will have information about drying times on – usually a “touch dry” time and a “recoat” time.
These are just indications, and the actual time may vary depending on both how porous the substrate is that you’re painting, and environmental conditions (how warm/cold/humid it is). Paint dries by both absorption and evaporation; if the surface is porous, it will absorb paint faster.
If the room is already very humid and has little air-flow, this will slow down the drying time. Equally, if you’re painting a poorly insulated wall that is cold, that could also take a lot longer to dry as water from the atmosphere will naturally condense on these areas.
Most decorators will of course want to crack on with the second coat of paint as quickly as possible, because nobody wants to be sitting around twiddling their thumbs (like I’m doing now!). I’m sure we’re all guilty at times of ignoring the “recoat” time to some extent and getting the second coat of paint on soon after the first is touch dry.
In many cases this doesn’t cause a problem, but there are situations where rolling over paint which isn’t fully dry can cause the first coat to fail; sometimes it may peel off there and then, other times it comes away at a later date. Fixing a problem like that will always take longer than simply waiting an extra hour for the paint to dry sufficiently in the first place.
Unfortunately, there aren’t any “hard and fast” rules for how long different types of paint will take to dry. It’s not possible to say that vinyl matt emulsion paint can always be recoated after three hours, for example, because each manufacturer will have their own formulation, which will take more or less time to dry.
A Real Life Example of Having to Wait Varying Periods Between Coats of Paint
Last week I was painting a child’s bedroom, and the homeowner wanted me to use hard-wearing emulsion on the walls. Three walls were to be one colour, and the fourth to be a feature wall in a different colour.
As it happens, the two colours were made by different brands. The three walls in one colour took forever to dry – the recoat time on the tin was stated as four hours and it must have been at least that; the room became extremely humid from all the moisture evaporating from the paint, which then slowed the drying time down.
I had to come back the next day to do the feature wall and got the second coat on less than two hours after the first – same type of paint, but different brand, and different drying conditions (less humid).
It’s hard to know prior to applying it how long you will need to wait for paint to dry before you can apply additional coats.
So, the simple answer is to go with the recoat time as stated on the tin and be prepared to adjust slightly depending on the environmental conditions. If you can’t find the information on the tin, go to the company website and find the technical data sheet for the paint you are using; it should always be stated on there.
Right, hopefully that first coat should be dry now – back to work!
How Long Should You Wait Between Coats of Paint? – by Robin Gofton of Wokingham Decorating Services
For Decorators Forum UK