I’m starting a job of installing thin natural stone on an exterior cinder block wall. All my previous experience has been with stone and tile indoors, so this is new. My biggest challenge has been getting the stone to stick on the wall, a problem I never had with thinset and tile/stone inside.
My first attempt, using Type N mortar as had been recommended, was a disaster as that was like trying to get stone to stick using nothing more than wet sand.
I’ve now been advised to use Type S mortar (with sand obviously) plus add additional portland cement and “perhaps” even some lime in order to make it sticky enough to hold stone on the wall and to be strong enough to handle the elements (Central Virginia).
After doing some reading, I have some questions:
– Isn’t Type S mortar just portland cement and lime (plus the sand)? So why use BOTH Type S and add portland and lime, too?
– If I add the portland but not the lime, will it set up? Isn’t the lime required in the portland in order to make the chemical reaction even happen?
– Everyone has said NO to thinset. Why is this? The bags say it can be used inside or out, with tile or natural stone.
Thanks in advance for the help.
Wally
Replies
I am no mason, but http://www.eldorado.com has a cultured / manufactured stone installation page with application to a block wall included.