Tena
I am renovating the laundry room. The house was built in '78 and seems well-drained, etc.
Previously, there was some type of wet room wallpaper that I tore down.
Now I have three walls with drywall and one plastered concrete wall. Two walls with drywall are regular interior walls. The third drywall wall is the exterior wall that seems to have a plastic film behind the drywall? I suspect it’s concrete block with asphalt, insulation, plastic, and then the drywall. The last wall is an interior wall made of concrete block that has been slightly plastered.
My question now, when I apply Finja Gypsum Plaster to the walls, is whether I need a primer or not. I don't want to seal the walls so they can't breathe. Can the plaster be applied directly to the drywall and the plastered concrete wall, or will it come off immediately? I'm a bit hesitant about the primer since I don't want double moisture barriers considering the plastic film.
Does anyone have deep knowledge about gypsum plaster?
I am renovating the laundry room. The house was built in '78 and seems well-drained, etc.
Previously, there was some type of wet room wallpaper that I tore down.
Now I have three walls with drywall and one plastered concrete wall. Two walls with drywall are regular interior walls. The third drywall wall is the exterior wall that seems to have a plastic film behind the drywall? I suspect it’s concrete block with asphalt, insulation, plastic, and then the drywall. The last wall is an interior wall made of concrete block that has been slightly plastered.
My question now, when I apply Finja Gypsum Plaster to the walls, is whether I need a primer or not. I don't want to seal the walls so they can't breathe. Can the plaster be applied directly to the drywall and the plastered concrete wall, or will it come off immediately? I'm a bit hesitant about the primer since I don't want double moisture barriers considering the plastic film.
Does anyone have deep knowledge about gypsum plaster?
Primer does not provide a waterproof layer but is used to bind porous substrates and improve adhesion. Depending on the primer and substrate, you also mix it with water. If you don't use it and the substrate is absorbent, there is a risk that the surface where the gypsum plaster is applied will absorb moisture, and you may experience dry detachment, it may sound hollow if you tap on the plaster, or, in the worst case, it may detach from the wall.
Ok, thank you for your response.
Some primers are surely at least dense? The primer I used in the bathroom was like an adhesive that felt rubbery.
I saw that Finja had a primer but where I shopped they only had a giant bucket for 900kr.
Maybe there is another brand that has about a 1-liter bottle?
Some primers are surely at least dense? The primer I used in the bathroom was like an adhesive that felt rubbery.
I saw that Finja had a primer but where I shopped they only had a giant bucket for 900kr.
Maybe there is another brand that has about a 1-liter bottle?
No, I first had primer and then rubber in the bathroom. But I also thought the primer felt rubbery/sticky. But if it's as you say that the primer breathes, then it's not a problem. I'll buy a 1-liter primer. The gypsum plaster primer Finja had seemed to only be available in about an 8-liter bucket at my local hardware store.Stefan N said:
I just tried applying some gypsum plaster on one of the walls. Couldn't help myself.
Amazingly easy to work with even though I've never plastered before. I realized I'm applying it so thin that it shouldn't even form loose flakes. It’s only about 1-2mm thick on most of the gypsum wall. If it holds up well, I'll skip the primer.
It turned out great without primer. I did apply a thin layer though. Maybe pieces come off if you slap on a cm or two? This is guaranteed to sit like a rock. I pre-wet the wall so the plasterboard paper was wet when I applied the gypsum plaster.
I also redid the fireplace and that turned out awesome as well. The old brick fireplace is now smooth and white.
I haven't painted the walls in the basement yet, but it still looks good.
Tip - if you mix more to touch up the walls, it might end up a different shade.
I also redid the fireplace and that turned out awesome as well. The old brick fireplace is now smooth and white.
I haven't painted the walls in the basement yet, but it still looks good.
Tip - if you mix more to touch up the walls, it might end up a different shade.
Also tried applying a thin layer without primer and it sticks perfectly. It was on a primed drywall.
Applied a layer of primer last night and will plaster the rest of the walls tonight, let's see if there will be any difference, I don't think so. Maybe it will be easier to apply the plaster? (not that it was difficult)
Applied a layer of primer last night and will plaster the rest of the walls tonight, let's see if there will be any difference, I don't think so. Maybe it will be easier to apply the plaster? (not that it was difficult)
Polished the last two walls yesterday, which also got a layer of primer. You can't see any difference, and it doesn't feel like it's adhered more strongly. It did feel like you could apply an even thinner layer of plaster because of the primer, though. The result turned out great anyway, really fun We created an irregular pattern with brushes, resulting in a nice, lively texture. Nicer than textured wallpaper, less work, and cheaper!
We created an irregular pattern with brushes, resulting in a nice, lively texture. Nicer than textured wallpaper, less work, and cheaper!
The plaster is quite forgiving and usually adheres well.
The risk, however, is that there might be dirt/grease or dust behind it, which can cause it to come off. You should always apply a primer when plastering with gypsum plaster, especially if applying it on a painted or smooth surface.
For lightweight concrete walls, the primer is mixed with 3-4 parts water, and then you can spray it on with a plant watering bottle. I have one where you pump pressure into it, and then you just spray generously.
"Clean" lightweight concrete only needs to be watered.
The primer becomes like a sticky surface, a bit like the back of tape, to help the plaster adhere better.
The risk, however, is that there might be dirt/grease or dust behind it, which can cause it to come off. You should always apply a primer when plastering with gypsum plaster, especially if applying it on a painted or smooth surface.
For lightweight concrete walls, the primer is mixed with 3-4 parts water, and then you can spray it on with a plant watering bottle. I have one where you pump pressure into it, and then you just spray generously.
"Clean" lightweight concrete only needs to be watered.
The primer becomes like a sticky surface, a bit like the back of tape, to help the plaster adhere better.
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