A newly plastered wall or ceiling will obviously be wet. Therefore, you must give it enough time to dry before painting. A very frequent question asked by most homeowners and DIY painters is how long I should wait before applying paint on new plaster.
In fact, there is no definite answer to this question since the walls and ceilings will dry out at different pace. Besides, it also depends on other conditions of the room, for e.g.humidity level, temperature etc. In general, the plaster of a normally centrally heated house will take around 4 weeks to dry properly. However, in Lyndhurst, NJit can take as long as 5-6 weeks if the temperature is low and with extra heat in the room it will dry in just three weeks.
The reason why you should not paint new plasters before the wall is completely dry is because most paint simply creates an air tight layer over the wall. Moisture from the new plaster is trapped under the paint and cannot evaporate off. The moisture in the wall then affects the wall and develops abnormal mould growth. It also reacts with the salts in the wall and creates problem that is really difficult to deal with.
If you paint the new plaster before it is properly dry, this may create problem in the long run. However, in certain cases there are situations when you need to paint the new plaster before it is properly dry. In such cases, you can purchase a special kind of paint available in the market i.e. Microporous Paints. This paints allows the surface of the new plaster to continue breathing and evaporating during the process the plaster is drying out. These types of paints can easily be available in lot of DIY stores.
Microporous paints are actually less densethan traditional water or oil based paints. As a result, in certain cases, although the wall is dry, it is advised that you over-paint the new plasters with emulsion. However, before using this paint, you should read all the instructions written on the paint can to get information on how to apply the first coat of paint onto the newly plastered walls and how long to leave it to dry.
Nevertheless, painting new plaster is really difficult and you should consider hiring a painting contractor in Lyndhurst NJ to paint your newly plastered walls.