I'm a newcomer, so forgive me if I'm asking wrong question, in wrong place ..... I'm going to paint a concrete floor (using standard floor paint from DIY place). How long should I leave the newly-laid concrete before painting it? (Is there a formula I should use - eg allow 'x' number of days' drying time for each 'y' mm of concrete depth?).
The floor is indoors (in a centrally-heated house).
I would leave it at least a month. Painting a concrete floor needs a lot of preperation, it needs shotblasting, fine scabbling, scaryfying etc. You cant just apply paint to finished concrete. It will need sealing. I think you should think about it very carefully, otherwise you will be painting the floor time and time again. Maybe look up a specialist firm ???
Waiting for concrete to dry - and waiting for the Relative Humidity at the surface (RH) to fall to a level acceptable for the intended floor coating product - is important, but not always essential. For example we have epoxy floor coatings which can be applied to damp screeds and concrete.
Seanandruby is correct, you must prepare first, or early failure is likely.
Simple answer - the concrete needs to have a moisture content of less than 3%, 5% maximum - you hire a moisture metre for the day to test (Check with Plascon/Dulux techs). It can take a year to get to this point. Then its preparation, first degrease. then etch primer, then paint. After MANY attempts, I left the concrete for as long as posible then used a road paint. Otherwise go the Ronacrete route.
Many thanks for the advice so far, although I've become slightly worried that this is not going to be as straightforward as I'd thought: I don't mind how long I have to wait (any advance on a year ?) ........ but I'd not expected to have to do shot blasting, acid etching or anything like that! (All beyond my capabilities and, I suspect, my budget).
The floor has been power-floated, and is nice & smooth. I'd thought my only dilemma would be whether to use a surface sealant (PVA?) or the kind that soaks in, before painting it.
Any further advice would be very, very welcome.
..... I'm going to paint a concrete floor (using standard floor paint from DIY place). How long should I leave the newly-laid concrete before painting it? (Is there a formula I should use - eg allow 'x' number of days' drying time for each 'y' mm of concrete depth?).