What went wrong?

[thomste]

Renovated a brick chimney with
mesh and hydraulic lime mortar and painted with silicate paint.
After two years it looks like this.
What went wrong?
The chimney was not used and the flues are sealed at the top.

 

[hempularen]

There is a claim in this old post about silicate paint and lime mortar:

Painting with silicate on lime mortar is not relevant because the silicates require at least class C on the mortar.

https://www.byggahus.se/forum/threa...t-andra-relaterade-fragor.120591/#post-870023

I don't know if it's true, but maybe it's an explanation?

 

[Plupp 405730]

Renovated a brick chimney with mesh and hydraulic lime mortar and painted with silicate paint.
After two years, it looks like this.
What went wrong?
The chimney wasn't used, and the flues are sealed at the top.


[image]

How long did you let the plaster dry before painting?
Yes, it's true that you shouldn't paint lime mortar with silicate paint, instead, you usually paint lime plaster with lime paint...