Skimming Over Old Plaster Walls
Prepping Before Skimming Over Old Plaster Walls
Before you can consider skimming over old plaster walls , the walls will most likely be in need of some prep. work first .This can vary greatly .Any lose plaster will need removing and a backing plaster applied if necessary .You will need the best surface possible before your skim can be applied if you want it to last .
A good way to be sure if the plaster is still attached to the wall is to run a metal object across the wall .Listening for a hollow sound between the backing plaster and the brick wall .You can try this with most metal objects .Generally a key or coin will be nearest too hand and is as a good a tool for this as any .There will be a distinct change in sound as you cross any patches of plaster that are loose .It wont need an expert to pick these loose sounds of plaster patches up .Mark them with a pencil if you intend to repair them yourself .In rare cases all the original plaster may be shot and in need of re-plastering .
After all the prep work is completed ,and before the plastering can start ,the walls will need to be coated with a diluted pva mixture .High suction backgrounds are porous and will suck out any moisture from the plaster ,drying it in a fraction of the time ,causing it too crack and fall off .So any old plaster work ,whether painted or not ,will need 2 good coats of pva first .Unlike new plaster board ,which needs no preparation other than to scrim tape the joints .
If your attempting this yourself ,for the first time ,you should start on a small area first to ensure you are getting the technique right .Plaster patching after a house re-wire or after a leak ,are great places too start to learn how to plaster before attempting anything as big as skimming over old plaster walls .Now find out how to mix plaster properly and you can get stuck in .