Smooth plaster surface

[Johan FK]

I have plastered the basement walls with lime mortar. How do I get a really smooth surface? Right now it is a bit grainy from the larger stones in it.

/ Johan

 

[The Tor]

If you want a smooth surface you should use fine plastering: http://www.weber.se/fasad-puts-och-...rbruk/putsbruk/webercal-144-kalkbruk-fin.html

 

[Johan FK]

Thank you for the answer. I have used Finjas 0-3 mm but it is still a bit grainy as if there are larger stones in it. Have I done something wrong, is it common for it to be like that if it hasn't been mixed enough?

 

[Fasting65]

0-3 is not exactly fine-grained. There are finer mortars that you can use as the final layer. I believe the grains are 0-0.1 then. Check with Weber.

 

[Stefan N]

0-1 mm is fine bruk.

 

[The Tor]

Is it Finjas Hydrauliskt kalkbruk (0-3) that you have used?
They also have a finer version of this mortar called Hydrauliskt kalkbruk Fin (0-1):
http://www.finja.se/visaprodukter.5548105.hydrauliskt-kalkbruk-fin-0-1-pumpbart

Weber.cal 145 vattrivningsbruk is a pure luftkalkbruk at 0-0.5 mm:
http://www.weber.se/uploads/tx_weberproductpage/weber.cal145vattrivningsbruk_datasheet.pdf

 

[Johan FK]

Aha, that's good. How thin can you apply this? Should you pre-treat the already plastered walls somehow, like sand down the coarser grains, or should you aim to make it thick enough to just cover them?

 

[The Tor]

Aha how nice. How thin can this be applied?

It is usually specified in the product sheet. Finja kalkbruk fin = 3-5 mm. Weber kalkbruk fin 2-3 mm.

Should one pre-treat the already plastered walls in some way, like sanding down the coarser grains, or should one aim to make it thick enough to cover just those?

You should not need to do that. However, it can be good to pre-water.