The Brew Cabin

Posted: **Fri Oct 04, 2013 7:57 pm**

I laid an Indian Sandstone circle on a full mortar bed earlier this year. I did half one week and the second half a week later. The weather turned very cold the second week (Feb) but I decided to go ahead and lay the slabs anyway as I had hired the mixer

The slabs laid in the second week are all lifting, whereas the first slabs seem OK.
Is there any way of avoiding having to either chip away at the mortar bed and risk disturbing the "good" slabs - or starting again and removing the entire concrete base? What about mortar repair products or epoxy mortar - will this bond the slabs to the concrete base in a very thin layer?
All advice most appreciated!

Posted: **Sat Oct 05, 2013 12:35 pm**

As you realise the slabs probably lifted because the mortar was damaged by frost. The problem with the remaining frost damaged mortar is that it never really set hard it has a slightly crumbly texture and so will not be a stable base. If the mortar is truely rock hard you could try setting the slabs with tile cement but really the best bet is to relay.

Cut through the bedding between the old slabs and the afected ones so you don't loosen the good ones as you remove it.

Posted: **Sat Oct 05, 2013 3:03 pm**

^^
excellent advice by Neo
once the frost has got them they are no good
need to be relaid
LLL

The Brew Cabin

Relaying part of a concrete base patio