Open inside corners in plaster walls
Working on my own place right now. Built in 1903, virtually all interior walls are original plaster on lath strips.
I am working in the landing at the top of the stairs. Virtually all of the plaster had come free from the lath, and all of the walls had that heavy kraft paper they used to keep everything together and hide the cracks. I have removed all of that and adhered the plaster back to the lath with construction adhesive.
There are two inside corners where there was particular separation between surfaces.
In the picture with the white wall to the right, and a little bit of window sill showing, both walls are plaster. The one to the right is exterior. Before I stripped the walls the paper in the corner had those bias wrinkles in it that indicates that the walls had shifted.
The other picture shows plaster and lath wall to the left of the corner and a brick chimney with plaster on it to the right.
After I get the holes and small cracks filled/patched, I will go over all the walls with Adfors Super Crackstop and bedding compound.
My question is about the best way to address those two corners. I doubt that the house is done moving, so I’m thinking about using a sealant with some flex to it (NP1?), as opposed to a glass-reinforced cementitious filler.
Thoughts?
Replies
No picture showing up for me.
Although the files were under the 3mb limit, they apparently did not upload. They're up now.
A lot of people have ways to deal with loose plaster. In my opinion the best is to re-key the plaster by simply drilling holes in it with a masonry bit that align with slots in the lath. If you make quarter sized holes every 8-10 inches along a crack and fill with hot mud it will anchor the loose plaster as long as the mud pushes through to the back of the lath. I've never heard of putting an expansion joint of chalking corners. It would be better to figure out why the house is settling and try to support it where it needs it.