Mixing grout with SBR

[Unregistered]

Hi

I have a flat roof to tile with slate tiles and I'd like to make a grout to be waterproof. I've never used epoxy grout and don't want to (not sure if you can use it on slate anyway). I was thinking to mix grout with SBR - what are your thoughts?

 

[widler]

Don't think it would harm it, but when you have sealed the stone and grout it will be waterproof anyway .

 

[Dave]

SBR won't make it waterproof..

 

[Unregistered]

I have sealed the slate on previous work and it proofed to be watertight for a year or so. Let me explain the situation I'm in.
Few years ago this terrace was tiled with asbestos tiles sicked on layer of bitumen. Under the bitumen was few layers of felt and concrete deck. All of this was stripped down to bare concrete and new deck installed. New deck was covered with GRP - some fibreglass and resin. Slate tiles went on top. Now we've found out that there is a problem with GRP deck as it's leaking. Now I thought of two options:
1. find watertight grout and re-grout the whole terrace
2. lift the tiles, put another layer of 6mm plywood directly on existing deck and apply Mapelastic Aquadefense Liquid Rubber Waterproofer then re-tile.

Option 2 seems to be the best way but a bit pricey too.
Do you have any suggestions?

 

[Tile seller]

I wouldn't try chemical mixes unless specified ok by the manufactures. You can seal grout but I cant see it lasting as a long term solution.
Epoxy's good but not cheap and any movement in the tiles means gaps and waters through again.

Option two seems the only way sadly. I cant offer any advice on how best to complete this option though as I'm no roofer.

 

[Unregistered]

I thought epoxy would be flexible so it would allow for a slight movement but as I said, never used it before so not 100% sure. Have you tried epoxy on slate? Does it leave a glaze on tiles? The terrace is approx 40m2.

 

[Lithofin BOB]

Grout protectors or impregnator across the stone or grout , as TS said will not protect for to long, breathable, water may still poss bleed as maintenance products not tanking, ardex do a hybrid epoxy which we tested on very anti slip tiles came of a treat, not sure for naturals, this would give you chem and water resistance but un sure on application on slate , could you do a test board with spare slates to test for release and finish.Would ring them also to discuss suitabilty with slate and movement . Perhaps the guys could comment on here on hybrid product. Can't recall name

 

[Stef]

Unless this is stripped back & done right then it will leak.
I wouldn't even dream of fitting 6mm ply then tiling on top of aquadefence.
Glue & screw an appropriate board suitable for outdoor use then aquadefence it.

 

[Unregistered]

I have some spare slate tiles. I think you're talking about Ardex EG8. I'll try to get some info from manufacturer and I can test it on spare tiles.

 

[White Room]

Don't mix sbr with your grout because it will be a nightmare to clean off, I tried it just the once never again...that'll teach me to try and be clever.