Hi,
as the space requirement is constantly increasing, I have started to prepare a previously unfinished space in the basement. The house was built in the 50s and the walls I want to prepare seem to be built with stones resembling concrete blocks but are a bit more robust. My idea is just to apply some kind of plaster and then paint over it since other parts of the basement by previous owners have been done similarly. But along the way, some questions have arisen.
I tested on a small wall with the mortar the building store recommended.
http://www.weber.se/fasad-puts-och-...utsbruk/weberbase-224-puts-och-murbruk-c.html
That particular wall was put up in recent years and is built with regular concrete blocks.
After a few days of drying, you can still clearly see the joints between the concrete blocks as a moist pattern on the newly built wall layer. Is this "normal" or does it indicate moisture?
The mortar used feels a bit "sandy", if I touch it with my hand, sometimes small particles come off. Is it okay to paint directly on this, or should a firmer surface layer be applied? In another place, I tested last year to spread some joint compound after laying tiles, and it reminds me more of the surface I expect. Is it an option to do so, or will such a surface be so dense that no moisture can come in or out?
If it is okay to paint directly on the plaster, how long should you let it dry before? (In the basement, it is about 15 degrees and somewhat more humid than on the other floors)
as the space requirement is constantly increasing, I have started to prepare a previously unfinished space in the basement. The house was built in the 50s and the walls I want to prepare seem to be built with stones resembling concrete blocks but are a bit more robust. My idea is just to apply some kind of plaster and then paint over it since other parts of the basement by previous owners have been done similarly. But along the way, some questions have arisen.
I tested on a small wall with the mortar the building store recommended.
http://www.weber.se/fasad-puts-och-...utsbruk/weberbase-224-puts-och-murbruk-c.html
That particular wall was put up in recent years and is built with regular concrete blocks.
After a few days of drying, you can still clearly see the joints between the concrete blocks as a moist pattern on the newly built wall layer. Is this "normal" or does it indicate moisture?
The mortar used feels a bit "sandy", if I touch it with my hand, sometimes small particles come off. Is it okay to paint directly on this, or should a firmer surface layer be applied? In another place, I tested last year to spread some joint compound after laying tiles, and it reminds me more of the surface I expect. Is it an option to do so, or will such a surface be so dense that no moisture can come in or out?
If it is okay to paint directly on the plaster, how long should you let it dry before? (In the basement, it is about 15 degrees and somewhat more humid than on the other floors)
There is another thread on this forum regarding drying time on plaster:
http://www.byggahus.se/forum/faerg-mala-tapetsera/176546-torktid-innan-silikatfaerg.html#post1355294
That small particles sometimes detach from the plaster (as you describe it) is probably quite normal. As long as not too much falls off, it's probably not a concern. If a lot falls off, it could possibly be an indication that the plaster has been mixed incorrectly?
http://www.byggahus.se/forum/faerg-mala-tapetsera/176546-torktid-innan-silikatfaerg.html#post1355294
That small particles sometimes detach from the plaster (as you describe it) is probably quite normal. As long as not too much falls off, it's probably not a concern. If a lot falls off, it could possibly be an indication that the plaster has been mixed incorrectly?
How sensitive is the mixture and the final result if, say, one ends up adding a couple of deciliters too much or too little to an estimated half bag of water when it should be 5 liters for a 25kg bag? Does such a mix-up make a noticeable difference? I tried different mixtures in the beginning to get to know the material and see how the properties changed when I initially thought it was a bit too dry. My idea is to use my first wall to test and learn on so that the others turn out as expected.
After taking a good look at the wall, I see that in some places a smooth, fine hard surface has formed, while in other areas there still seems to be a bit of "loose sand." I assume that there was too little water there, or that the wall behind absorbed some of the water that was in the mortar. Can I, therefore, conclude that it's better to have a bit too much water than too little? Or is it about ensuring that even after applying the mortar, you should dampen the wall with a spray bottle to ensure the mortar really bonds with the moisture?
Or are there other consequences of too much water, besides making it difficult for the mortar to stick to the wall? Is it better to add a little extra water at the end and apply the final layer over the others? What happens if I apply a new layer on top of the old one, is there a risk that it might come off if the groundwork isn't perfect, or can the new layer bond with the old one?
Or are there other consequences of too much water, besides making it difficult for the mortar to stick to the wall? Is it better to add a little extra water at the end and apply the final layer over the others? What happens if I apply a new layer on top of the old one, is there a risk that it might come off if the groundwork isn't perfect, or can the new layer bond with the old one?
Don't know, but I usually pre-water the wall that is going to be plastered so that it doesn't absorb all the water from the plaster, and I also usually water it afterwards when the plaster has started to set, as you do with concrete. So far, all plaster has become hard and nice!
I think that was the problem, the first time I didn’t water the wall at all, the second time I used a spray bottle to moisten it but somewhere I read that you could use the water hose and soak it thoroughly. How do you who are reading the thread do it?
But the conclusion should be that it’s better to have a little too much than too little water.
But the conclusion should be that it’s better to have a little too much than too little water.
It is often said that you should keep it moist for about 2 days to ensure durability. This might vary somewhat between products? But in general, you should keep it moist during this time period.
You should keep it moist, not wet. It is probably enough to spray a little with a plant sprayer (depending on how large the wall is?). The main thing is that the mixture does not dry out immediately. You can also cover it with plastic to avoid having to spray water as often.
You should keep it moist, not wet. It is probably enough to spray a little with a plant sprayer (depending on how large the wall is?). The main thing is that the mixture does not dry out immediately. You can also cover it with plastic to avoid having to spray water as often.
The room has a total of 4.5 square meters of floor space, so there are no huge walls, one wall at 1.5 x 2 meters that I've tested a bit on and two walls at about 3x2 meters. But it's probably a good idea to take one wall at a time until you've got the hang of the technique 