I have a house where the interior walls consist of lightweight concrete that is very soft. I have now mounted various wall sockets and made VIP pipe runs in several walls.
I need to find a good repair concrete that I can use to fill all these cavities. Regular wall filler doesn't work because the cavities are too large. Mixing my own concrete is difficult, and it's also hard to get the right consistency so that it doesn't run out of the cavities.
Can anyone recommend something good that is easy to apply and easy to work with? Preferably a bucket, as a few liters will be needed.
I need to find a good repair concrete that I can use to fill all these cavities. Regular wall filler doesn't work because the cavities are too large. Mixing my own concrete is difficult, and it's also hard to get the right consistency so that it doesn't run out of the cavities.
Can anyone recommend something good that is easy to apply and easy to work with? Preferably a bucket, as a few liters will be needed.
Have done the same thing in my house. I used Serpo 224. Available in 25 kg bags, just add water. You can mix a little at a time and get a feel for it. Do not mix the whole bag at once if you're not experienced; instead, pour some mortar from the bag into a bucket or other container and add a little water and stir. Be careful with the water, it can easily become porridge if you add too much. That's why it's good not to mix everything at once. Then you have the opportunity to mix in more mortar if it gets too thin. The mortar should not run off the trowel when it's ready, should be a bit firm. Dampen with a spray bottle where you will lay/fill in with mortar. If there are large cavities, it may be necessary to fill in twice. Push in the mortar and smooth out. Putty over it once it has dried.
It is important to keep in mind that low-alkaline products should be used when dealing with lättbetong, depending on its age. Serpo 224 is not low-alkaline...
As mentioned: it also depends on the age of the lightweight concrete. The cutoff is around 1980. Before 1980, alkaline products are fine, e.g., Serpo 224. After 1980 = use low-alkaline, e.g., Serpo 131. If you are uncertain about the age, choose low-alkaline for safety's sake.
Thought the same thing. Finja has a quite ambitious substrate guide for gypsum plaster: http://www.finjabetong.se/aktuell/pdfny/Underlagsguide_Gipsputs.pdfoskis 123 said:
As for Maxit, there's Serpo 105/130/131, which are all low-alkaline.
Gypsum plaster can definitely be used as long as it's not on surfaces with a risk of penetrating moisture, such as in a basement. Gypsum plaster is available from Finja, maxit, and Knauf, for example.
Thanks for all the tips.
My house is from '75 and there is so-called blåbetong in some of the walls that I need to putty. These are not basement walls (moisture).
I don't know if this blåbetong is equivalent to regular lightweight concrete.
So then it's one of the Serpo products or Plaster that applies.
Is the plaster pre-mixed when purchased?
You mention Finja-Maxit-Knauf, I haven't seen these in the Gothenburg area, or could I have missed them.
My house is from '75 and there is so-called blåbetong in some of the walls that I need to putty. These are not basement walls (moisture).
I don't know if this blåbetong is equivalent to regular lightweight concrete.
So then it's one of the Serpo products or Plaster that applies.
Is the plaster pre-mixed when purchased?
You mention Finja-Maxit-Knauf, I haven't seen these in the Gothenburg area, or could I have missed them.
Bygg-Max, K-Rauta, Hornbach, Bauhaus, Silvan, Beijers are probably the hardware stores that exist in my area. Can anyone give a tip where they are so I can avoid driving around looking for them? Calling probably doesn't work that well, at least not for the big stores.
Beijer and K-Rauta have Maxit. I THINK Hornbach also has Maxit.
Bauhaus has Combimix. I have used their gypsum plaster and think it works great. It comes in a 10-liter bucket = conveniently lightweight to carry and easy to reseal. You add water and then you’re ready to go. Maxit’s gypsum plaster probably works just as well (I’ve only used their concrete).
I don’t know what Bygg-Max and Silvan have.
Bauhaus has Combimix. I have used their gypsum plaster and think it works great. It comes in a 10-liter bucket = conveniently lightweight to carry and easy to reseal. You add water and then you’re ready to go. Maxit’s gypsum plaster probably works just as well (I’ve only used their concrete).
I don’t know what Bygg-Max and Silvan have.