My DIY plaster patch job turned into a total disaster

I decided to fix a crack in my living room wall last weekend, and I thought I knew what I was doing. I used a premixed joint compound from Home Depot on the old horsehair plaster, but it just peeled right off after drying. Turns out you need a bonding agent or you have to use a specific plaster mix for that old stuff. Now I have a bigger mess than when I started, and I'm looking at a $200 repair bill if I call a pro. Has anyone else run into this problem with plaster in ABQ? What did you use to get it to stick?

3 comments

3 Comments

wesley_adams6d ago

Man, I feel your pain. My grandpa used to say "plaster is a jealous mistress" and man was he right. I tried to patch a hole in my 1920s bungalow last spring and ended up with a crater the size of a dinner plate (which my wife still brings up at dinner parties, ugh). The trick I finally found was mixing a little bit of PVA glue into the water before adding the joint compound. It sounds hacky but it actually worked. Of course, it took me three trips to the hardware store and a lot of colorful language to figure that out. Now I have a beautiful patch that only I know is there, and a newfound respect for old houses.

the_max5d agoTop Commenter

@wesley_adams the "jealous mistress" line is GOLD. Your grandpa knew what he was talking about. But here's something nobody brings up with old plaster: it's not just the walls you gotta worry about, it's the whole damn house shifting around them. That 1920s bungalow of yours has probably settled a few inches since it was built, and plaster doesn't bend like drywall does. So even a perfect patch can crack again next winter when the foundation moves a little. I found that out the hard way when my ceiling patch turned into a spiderweb after one cold snap. The PVA glue trick is smart but also consider using a fiberglass mesh tape instead of paper for the seams. It lets the patch flex with the house without splitting. Just my two cents from fighting with a 1910 foursquare for way too long.

patricialee5d ago

That "jealous mistress" line is perfect because old plaster really does demand all your attention and then some.