Hello,
I have just plastered approximately 10 sqm of basement wall and the wall looks great except for the last meter where something has happened.
Let's rewind. It's a basement wall in a row house facing the neighbor, i.e., not an exterior wall. With a remediation grinder, I sanded off the silicate paint that was on it and exposed the plaster. This wall is going to be tiled, so I needed to level it. Step 1 was to apply Weber's primer and step two was plastering with C mortar. I pre-watered the wall and post-watered the plaster. Still, the last meter looks like in the pictures.
The old plaster was very hard, so I didn't remove everything. Around the cracks, there is a hollow sound but not where the plaster looks okay. In the last picture, I have chipped away the plaster around a crack. The plaster around it is solid as a rock, but, as mentioned, not right at the crack.
I have two potential sources of error. Right where the cracks are, the wall was more uneven and the plaster layer became a bit thicker. I also managed to drop the last bag into the bucket with water, so the mix was not 100% according to instructions and was a bit looser. Could this be the mistake?
Would you chip away everything or just where there is a hollow sound and plaster the holes again? Need advice.
I have just plastered approximately 10 sqm of basement wall and the wall looks great except for the last meter where something has happened.
Let's rewind. It's a basement wall in a row house facing the neighbor, i.e., not an exterior wall. With a remediation grinder, I sanded off the silicate paint that was on it and exposed the plaster. This wall is going to be tiled, so I needed to level it. Step 1 was to apply Weber's primer and step two was plastering with C mortar. I pre-watered the wall and post-watered the plaster. Still, the last meter looks like in the pictures.
The old plaster was very hard, so I didn't remove everything. Around the cracks, there is a hollow sound but not where the plaster looks okay. In the last picture, I have chipped away the plaster around a crack. The plaster around it is solid as a rock, but, as mentioned, not right at the crack.
I have two potential sources of error. Right where the cracks are, the wall was more uneven and the plaster layer became a bit thicker. I also managed to drop the last bag into the bucket with water, so the mix was not 100% according to instructions and was a bit looser. Could this be the mistake?
Would you chip away everything or just where there is a hollow sound and plaster the holes again? Need advice.
Weber c-bruk 135? Cracks if you apply a layer thicker than 1 cm. If it's going to be tiled, chip away around the cracks where there's a hollow sound and apply in a few layers instead.
Edit: Now I saw the first pictures. It certainly looks like the mortar has run downwards. So either very wet mortar in too thick a layer. Or you may have over-saturated the wall when you pre-wet it, it should be damp but never soaking wet. Is it concrete block behind?
Edit: Now I saw the first pictures. It certainly looks like the mortar has run downwards. So either very wet mortar in too thick a layer. Or you may have over-saturated the wall when you pre-wet it, it should be damp but never soaking wet. Is it concrete block behind?
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Too thick a layer. I would have only scraped out the cracks and repaired (plastered) with tile adhesive. Then primer and tile adhesive before the tiles.
