Sooner or later, almost every plaster wall and ceiling develops cracks - if not in the broader expanses, then at least where flat surfaces join one another. Wind pressure on the house, structural expansion and shrinkage, traffic vibration, and household activities all contribute toward weakened plaster. Before any redecoration can take place, the inevitable patching must always be done.
How to fix big cracks
First, clean away all material that appears loose in and around the crack. If it's a fair-sized crack, crack to its deepest part, then undercut it so that it's wider underneath than on the outer surface.
How to fix smaller cracks
Little cracks can simply be brushed clean. With a spray, a sponge or rag, thoroughly dampen all surfaces of the crack. If this is overlooked, moisture from the new plaster will be absorbed into the wall, leaving the patch powdery and weak. Press the mix into the bottom of the crack, build up slightly more than necessary, smooth off the excess, and let it dry for 2 to 4 hours. Then use sandpaper to smooth off the excess. If you are going to paint later, a few strokes with fine-grit sandpaper will finish it off nicely.
How to patch holes
The general procedure for patching holes where plaster has fallen from the wall is the same as for patching cracks: undercutting, cleaning, dampening and applying new plaster.
How to repair a bulge
To repair a bulge, first create a hole where the bulge appears. Do this by rapping the bulge with a hammer until the loosened plaster falls out. Be sure to knock or pry away any loose plaster around the hole so as to have sound plaster at the edges of the patch.
If you don't want to to the job yourself and you are looking for well-priced, professional and friendly plasterers in Redbridge, give us a call.
Plasterer Redbridge covers east London and Essex, offering you our plastering, rendering and external wall insulation services. Get in touch on: 020 8088 0926