I need tips on how to renovate our basement wall in the best possible way.
Some background:
The entire room is about 40 sqm and has been used as a garage, among other things. The previous owner insulated the walls from the inside, even though the lower half of the wall is below ground level. I recently tore down this interior wall.
The plaster is somewhat affected by the old, built-in inner wall and in some places is crumbly and comes off easily.
In another room with the same issues in the basement, I applied a broad coat of filler, but when painting, the outer layer still peeled off.
I need a stable inner layer in this room.
I'm now considering whether to mesh the entire wall and apply new plaster. Or is there a better alternative?
Some background:
The entire room is about 40 sqm and has been used as a garage, among other things. The previous owner insulated the walls from the inside, even though the lower half of the wall is below ground level. I recently tore down this interior wall.
The plaster is somewhat affected by the old, built-in inner wall and in some places is crumbly and comes off easily.
In another room with the same issues in the basement, I applied a broad coat of filler, but when painting, the outer layer still peeled off.
I need a stable inner layer in this room.
I'm now considering whether to mesh the entire wall and apply new plaster. Or is there a better alternative?
The important thing is that moisture can move freely in the wall. Knock off all loose plaster and repair the damages; which mortar you should use depends on what it is plastered with today. Then paint with silicate paint that is vapor-permeable and handles moisture without peeling.
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The wall was rendered in the 60s.mexitegel said:
What type of render is best?
What you should adhere to is not using a harder mortar than what is already there today. I would guess that you have lime mortar/plaster in the walls today, and then you can continue with that.
Looks like concrete walls with paint on them in the pictures?
Am I wrong?
Am I wrong?
Yes, that's correct. These walls have been hidden by a stud wall with insulation, plastic, and chipboard.N neo11 said:
I might need to sand off this old paint?
Yes, you must.
If you are going to plaster cement mortar/lime mortar etc.
If you are going to plaster cement mortar/lime mortar etc.
Is it enough to sand with a giraffe sander and regular 120-grit paper or should you use something else?N neo11 said:
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If you are going to paint with a different type of paint (silikatfärg) you unfortunately need to remove all the old paint.
Check what it would cost to ice blast, it doesn't create as much dust as sanding.
Check what it would cost to ice blast, it doesn't create as much dust as sanding.
You can apply thinset with a coarse-toothed trowel on the walls, such as REX Fix.
Then plaster over it, so you get adhesion with the plaster on the thinset.
And avoid having to sand off the paint.
I have done this a few times, and recently did it on mosaic.
And it worked well.
However, on the mosaic, I used pink gypsum primer first, 2 times.
Then plaster over it, so you get adhesion with the plaster on the thinset.
And avoid having to sand off the paint.
I have done this a few times, and recently did it on mosaic.
And it worked well.
However, on the mosaic, I used pink gypsum primer first, 2 times.
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But if you instead apply primer and base mortar A over the entire wall, wouldn't that provide sufficient adhesion then?N neo11 said:
No.
The grundningsbruket doesn't adhere to the primer.
The grundningsbruket doesn't adhere to the primer.
What if you use mesh on the wall then?N neo11 said:
Then the plaster just hangs in the net, after 6 months - a couple of years it cracks.
And you have to redo everything.
Sand off the paint and plaster.
Apply fix and plaster.
These are the only options, but if you apply fix, you can't paint with silicate.
But if you don’t have any moisture problems, it doesn’t matter.
And you have to redo everything.
Sand off the paint and plaster.
Apply fix and plaster.
These are the only options, but if you apply fix, you can't paint with silicate.
But if you don’t have any moisture problems, it doesn’t matter.