Pointing cracking

[jonnypb]

Just had an indian sandstone patio laid but the pointing keeps cracking

1st of all they did a 4:1 sand cement mix which cracked and didn't look very good so then they went for a wet mix and then that's started cracking and coming away against each flag

I've seen their work before and it's always spot on so am disapointed with what they've done for me. They're coming back to have a look because they can't understand whay it's happening. It hasn't been baking hot either

Any advice or tips for good pointing?

[Rich H]

Sounds like they're doing the right thing by you so probably best to let them advise. If they take pride in their work they'll sort it.

What is slightly worrying is that it happened the second time, with a wet mix. It could be that the slabs have moved or settled?

[Tony McC]

If it's cracking, it's drying out before the cement in the mortar has a chance to properly hydrate. There are quite a few options, including using a retarder, using SBR/Ronafix, pointing late afternoon or early evening when the heat has gone from the day, covering the pointing with polythene or damp hessian, leaving it until cooler weather, soaking the flags beforehand to 'quench' their thirst...

It's down to your contractor to choose one or more of the above, or an alternative strategy. Personally, given the problems to date, I'd go for a polymeric.