Complete Project Management (CPM) are trusted and experienced Devon plasterers and wall boarders working around Exeter, Exmouth and Mid to East Devon and are qualified Devon builders. Please get in touch with us if you require any works completed in your home or business. See this video on youtube for a helpful demonstration on plastering – How to plaster a wall
Clean & Prep your surfaces!
Plaster won’t stick to just any surface, and you don’t want it to start falling away, so ensure your surface is ready to be coated. Therefore make sure it is clean – remove bits of existing plaster, dust or wallpaper.
Check the suction of your walls – I know sounds weird!
High suction porous backgrounds can suck the moisture from the plaster meaning it dries too quick. To resolve this, you may need to dampen the wall before you start plastering.
The best way to do this is to use a fine mist spray gun. Plasterboard or backing coat can be skimmed over without preparation.
Sounds over the top but it’s vital to have clean buckets, tools and equipment to ensure your plaster doesn’t go off and you get a better finish that lasts, dry plaster is a nightmare to remove from your tools and can cause drags in the plaster finish on your next job!
How you mix the plaster is important!
Always mix plaster by adding plaster to the water and not the other way around. Add just enough plaster first to make a heap on the top of the water and mix it so that it’s lump free, then slowly add the plaster to get the correct consistency either with a wooden stick or mixer drill.
Plaster and water mix roughly half and half – so half a (clean) bucket of water should make a full bucket of plaster. The plaster should be the consistency of melted ice cream – try standing a stick in it – if it can stand up, the plaster is mixed right.
How to plaster walls
When plastering a room, do alternate walls that do not touch as you risk damaging one wall while plastering the other. Keep the room cool; radiators should be turned off, or the plaster will dry out too quickly, making it difficult to apply and crack.
A good plaster finish can be achieved with a combination of positive firm pressure and the correct angle of your trowel. As the plaster on your trowel gets less and less with your movement, the angle between your tool and the surface gets smaller.
Don’t get plaster in your eye! Remember not to stand directly under the trowel.
You don’t need to worry too much about smoothness or trowel marks at this stage, just that it’s flat and even. Make sure the first thin coat is wet and pliable when you apply the second coat.
After the first two coats, the ‘trowelling up’ process begins. This is time to fill all those holes, remove your trowel marks and get it smooth.
Make sure before you start the plaster is tacky – pliable enough to push the plaster into the holes, but not so wet you make new holes.Don’t over polish the plaster on the final dry trowel stage – it should be even and slightly polished, but feel like eggshell – any smoother, it makes paint and wallpaper a nightmare to stick to.
For beginners, a good size to start with is 11 inches. While a larger trowels cover areas faster, it’s harder to control. When plastering an old trowel is much easier to use this way – some can be bought pre-worn.
Remember! Flatten, Amend Holes, Smooth Trowel Marks
Then when the plaster is quite firm, any trowel marks and ridges will be successfully smoothed out providing you have kept it flat allowing your trowel to sit flat on the wall.