Home Renovation

How to fix plaster walls?

March 11, 2011

Joe from Kelantan asks...I live in a hundred and fifty year old house, the walls are plaster that is bumpy and cracked. How am I to fix this problem without taking down the existing walls and putting up drywall, which is beyond my budget. Can you suggest something simple and inexpensive to make it look better before I paint the interior?

NECD responds...

With the charm of a 150 year old house comes a host of problems, one of them being cracked plaster walls. The best way to address the problem is to patch the cracks and skim coat the walls. This is a big job and a service most painters offer, so you might want to ask some for quotes even if you plan to do the painting yourself. If you are going to tackle the job yourself, here’s what you need to do: Since cracks are usually hairline, you’ll have to make them wider and deeper in order to patch them. First, dig into the crack all the way along its length making a valley until you’ve reached a depth in the plaster that is not cracked. I like to use a flat head screwdriver for this job. If you end up digging a hole right through to the lathe, that’s okay. Often the plaster is cracked beneath the paint, so make sure you get all the way to the end of the crack. If you have a large hole, cover it with mesh first, then plaster over, filling in your valley. Once dry, sand it smooth and the crack should be gone. Once you’ve finished fixing all the cracks you’ll need to skim coat a few layers over the entire wall surface, sanding between each layer, until the walls are smooth. Be sure to prime your walls before you paint to seal the plaster.