If live in a decades-old house, chances are, there are cracks in your plaster walls. These cracks are inevitable due to the movement of the foundation. Repair of plaster walls is moderately easy and not as complicated as dealing with a damaged plaster ceiling.
A damage that is fairly cosmetic and not disturbing is best addressed prior to a painting job. Since the repair will be apparent and might become a perceptible flaw. Coinciding the repair with the paint job is a smart move. Or you repair the wall damage and just make sure the patch blends with the rest of the wall surface.
Hairline Cracks in Plaster Walls
Hairline cracks are difficult to be fixed effectively because of they are particularly narrow. For hairline sized-damages, a patch is only effective if there is a substrate for it. For the patch to be fixed, you must widen the damage a little bit. For longer cracks, take out bits of plaster at certain interims along the crack to create a seat for the patch. Clean the surface of dust, debris and plaster residue using a damp towel.
1. With a spackling knife, fill the hairline plaster crack with plaster. Make sure to cover the grooves you’ve created, and overlap the existing wall plaster. This will let the patch to adhere to the vertical surface, guaranteeing a secure cover.
2. Leave the patch for at least 24 hours. If it seems to have withdrawn into the fissure, put another patch and allow it to dry for another day. Sand the patch to create an even surface. Then, prime and paint for a more refined look.
If there are too many hairline cracks, consider hiring a qualified plasterer to fix them all in one project to save on labor and to get quality results.