using an impermeable grout - externally

[stvkny]

Hi, I'm laying patio slabs in an outside courtyard area that overhangs a basement flat so want to point with something non-water permeable? Any ideas? I've been recommended epoxy resin slurry-style grouts but even they are water permeable....The slabs have a drop so the water should roll off but don't want it gathering in the joints and seeping down through...
Thanks in advance for any help
Stef

 

[Rich Midge]

Epoxy grouts are impermeable but in all honesty you'd be better off waterproofing the substrate before you start laying slabs. @Schlüter-Systems Ltd should be able to point you in the right direction.

 

[One Day]

As above - your approach is totally wrong. Waterproof the substrate, then incorporate a drainage layer (see Schluter or BAL) then tile as if water will get through, because it will!

Do it any other way and you'd better make sure your pl insurance stays up to date!

 

[stvkny]

thanks for the pointers guys
doing the substrate is not really an option...and I don't expect it to be entirely water proof - this is replacing a load of wobbly pavers on a sand base where water pools regularly up to an inch thick so I'm basically trying to minimise pooling and just helping the water to shift down and away. So its not like sealing a swimming pool or owt - essentially I'm just looking for something a bit less permeable than the usual polymeric sand or sharp sand so the water can "travel" a bit more...