Plaster on plaster

[Sakran]

I'm working on the basement. It had wooden framing and suffered moisture damage. The house has been re-drained, and all the wood has been removed. The basement has now been left for a year to dry. The next step is to fix the plaster. A color test shows that previous owners painted all walls with silicate paint. The interior walls are in good condition, only needing patching for nail holes. Any material recommendations? Fairly deep holes need to be filled. The exterior walls have been covered with plastic, possibly causing more damage. I understand that all loose plaster needs to be removed, but should I also remove all the paint? On the upper parts of the exterior walls, above ground, the plaster is firmly attached. The question is, can plaster be applied over silicate paint? Since the wall is so uneven, it seems easier to plaster the entire wall. It's difficult to only plaster where the plaster has come off. Recommendations for plaster? Can any plaster be applied on old plaster/mortar? The work was done in the '60s. Is it best to have the plaster/mortar tested to see what was used and choose accordingly?

 

[proffsrik]

It depends on how important it is to have a very fine result. If you keep the old firmly attached plaster and plaster below, you will get a visible seam. Additionally, the new plaster should be as hard/soft as the old one, otherwise you will get cracks. But if it is firmly attached, it's a dusty job to knock it off (use a P3 mask in that case) and there will be a few bags to take to the dump. A rotary hammer with a wide flat chisel makes the job much easier. If the outer wall is leca or concrete block, it should be possible to re-plaster it with regular C mortar.

 

[Plupp 353950]

I'm working on the basement. It has been framed with wood and got damp damage. I've redone the drainage around the entire house and removed all the wood. The basement has now been drying for a year. The next step is to fix the plaster. A color test shows that the previous owner painted all the walls with silicate paint. The interior walls are fine, only needing patching of nail holes. Any tips on material? Quite deep holes need filling. The exterior walls have been plasticized and presumably taken more damage. I understand that all loose plaster must be removed, but should I also remove all the paint? The upper part of the exterior walls, above ground, the plaster is holding firmly. The question is, can you plaster on silicate paint? Since the wall is so pitted and uneven, it seems easiest to replaster the entire wall. It's difficult to just plaster where the plaster has come off. Tips on plaster? Can any plaster be used on old plaster/mortar? The work was done in the 60s. Is it best to submit the plaster/mortar for testing to see what was used and choose accordingly?

Would patch up the holes with a C mortar. Then plaster entire surfaces with fine plaster and fiberglass mesh. That gives a cohesive look. New wall. (sto evo. Alt hayde)