So you’ve just had your room newly plastered. What to do next for painting new plaster?
The next step is to ensure that the plaster has fully dried out. you will be able to see this once you see all the dark patches dry to an even colour.
Don’t attempt to paint plaster until the plaster is fully dry. This should usually take between 3 to 5 days, if it has only been skimmed
If the walls have been bonded first and then skimmed over this can take longer than 3 to 5 days. Be patient and wait for the walls to fully dry out.
What paint to use when painting new plaster
Best paint to use in this circumstance is contract emulsion. Contract emulsion doesn’t contain any plasticisers or vinyl.
Vinyl is used as a protective element in paint that allows the paint to be cleaned down once dried.
This protective element forms a skin which is not absorbed by the plaster.
This means that the paint would sit on the surface of the plaster and not be absorbed into the plaster.
If you were to apply vinyl matt emulsion neat onto the surface of the plaster without a thinning, this can cause the paint to peel off the plaster.
You will need to mix up a mist coat for painting new plaster
Mist coat – ratio for painting new plaster
Basically, a mist coat is a watered-down coat of emulsion.
There are no real hard and fast rules about the ratio but I would use an 80% paint to 20% water ratio initially.
You can water down the paint further, but the further you water down the paint, the messier the application becomes.
Personally, I probably would not water down past 70% paint and 30% water and don’t water down below 50%.
Simply apply the mist coat using a roller and brush but taking care not to get it onto the woodwork trim.
Try to keep it off the woodwork as much as possible as this will cause priming issues when finishing the woodwork. (Woodwork paint can peel off if it is applied over weak emulsion).
If you are worried this could happen, simply use cheap masking tape to protect the top edges of the woodwork, prior to painting new plaster.
After mist coating – What to do next
After mist coating you should now have bright, white walls. These bright, white walls will now show up any imperfections.
Even the best plasterer in the world will not give you 100% perfect walls.
Sometimes cracks can appear through movement and you’d always find bits on the wall after painting.
This is the time to prepare your walls prior to the top coats.
If you see any cracks rake them out to make them slightly wider, and fill using water based powdered filler.
Rub your hand over the wall, if they feel gritty after painting them, simply give them a very light sand with light glasspaper, to remove the bits.
Also if you have had your walls skimmed you may have existing woodwork in place. Sand your woodwork down and fill the joint where the wall meets the woodwork.
Along the tops of the skirting and down the sides of the architrave, you should apply decorators caulk.
Decorators caulk comes in a tube with a nozzle and has to be applied using a skeleton or mastic gun. Mastic guns are cheap to buy and can be bought at all hardware stores.
After your preparation work has been completed you can then apply your required top coats.
Usually this would be two coats of coloured emulsion of your choice.
Always remember, preparation is everything in decorating. Take your time to do this properly, and the painting is easy after that