Repairing plaster walls and attaching things to plaster walls are discussed in this audio episode of The Handyguys Podcast.
The Handyguys received this question from a listener:
Would you please talk in detail about homes with plaster walls? I have never lived in a home with plaster walls until now and have only heard horror stories about putting things/pictures, etc, up on the walls. Can curtain rods be hung on plaster? Is it best to live with and/or “enhance” the cracks as a feature, or can they be fixed for a reasonable amount of $$? LOVE YOU GUYS! Thanks!
No horror stories here. Some cracks might be inevitable but we discuss in the show doing repairs and hanging things on your plaster walls.
Types of plaster walls
Traditional plaster are often made by installing strips of wood lath to the framing and then multiple coasts of plaster are spread over the lath. The plaster can contain pig hair or horse hair for strength. This may also be applied, in some instances, over a masonry, brick or stone wall.
Modern plaster, also called veneer plaster, is installed over a substrate board, similar to drywall.
Hanging things on plaster walls
Paul had good results with what he calls “tempered picture hanging nails” or also called hardened steel picture hook nails. You can get these at your local True Value hardware stores. Make sure you read the package for how much weight the particular hook can hold.
You can also use a screw into the lath or a stud. A trim head screw would be ideal but other screws could be used as well.
How about curtain rods? YES, you may be able to install the curtain rods with the hardware provided. If you are installing heavy curtains you will want to use a longer screw than may come with the curtain rods and then make sure you screw through the plaster and into the framing around the window.
If you are attaching heavy things like shelves, and you can’t screw into a stud, you may want to use a Toggle Bolt. These expand behind the wall to provide good holding power but will need a larger hole to install them.
All of these attachment methods assume your plaster walls are in good shape. What if they are not? Then you may have to repair the plaster before attaching anything to it.
Repairing plaster walls
There are a few types of common repairs; cracks, missing pieces or separated lath and plaster. The repair method will vary depending on what type of plaster you have and how it was originally installed.
Repairing plaster separated from lath
If the plaster has separated from the wood lath its likely because the “keys”, where the plaster connects to the lath, have broken off. You need to re-attach the plaster to the lath. This can be done with drywall screws but a better solution would be to use “plaster washers”. These washers are either metal or plastic. They are about 1 1/2″ wide, a screw is inserted through the washer and driven into the wood lath. The washer pulls the plaster tight against the lath. You will need these washers every foot or so (or every few inches depending on how bad the plaster is detached) to secure the plaster. Once the washers are installed, and the plaster is stabilized, you then skim a coat of new plaster over the washers to hide them.
Repairing cracks in plaster walls
It seems that cracks in plaster are sometimes unavoidable in old homes. These homes will move with the seasons and cracks will re-appear over time. A traditional approach to repairing cracks involves removing any loose plaster and then filling the crack with new plaster, also using some paper or fiberglass joint tape if the crack is large will help. If the house does move a lot then there may be little that can be done to keep the crack from re-occurring.
If the crack is small, Paul suggests just using a flexible, paintable, caulk in the crack. The flexibility of the caulk gives you a better chance that it will stay put and the crack will not re-appear. If that fails then you can try the more traditional method down the road.
Repairing holes in plaster walls.
For repairing a hole in a plaster wall Paul recommends “Patching Plaster”. It’s a fast drying plaster than comes in small containers for small repairs. Check it out and follow the directions on the package.
Tools for plaster repair
You will only need some basic tools and supplies for repairing plaster. You will need a 6″ wide putty knife and a 12″ wide knife, your plaster washers, a utility knife, some paper repair tape and a container to mix the plaster in. These can all be found at your local True Value.
We were one of the bloggers selected by True Value to work on the DIY Squad. We have been compensated for our time commitment to the program as well as our writing about our experience. We have also been compensated for the materials needed for our DIY project. However, our opinions are entirely our own and we have not been paid to publish positive comments.