Mixing grout with SBR

[DP Tiling]

A cement based backer board and a proper tanking agent is the only answer here, the mapeilastic aqua defense is great stuff, be sure to use the mapeband around the internals too.

Slate will need to sealed with an impregnator regardless, however, due to acidity/alkalinity of rain water it needs quite a bit of maintenance in that it wears a lot quicker.

Regarding the adhesive and grout, I personally would go for Keraquick and latex plus it is very well suited to external use and it's low water content and rapid hydration makes it ideal for porous stone also it is the same manufacturer as the tanking agent and eliminates risk of chemical incompatibility. Probably wouldn't go to an epoxy grout as I can see it being difficult to fully remove haze from slates textured surface.

 

[nybor62]

EG8, is a great grout easy to use imo

 

[Unregistered]

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.

Thanks for that advise.

DP - I know that tanking would be ideal but now when I compare the costs of re-grouting (2 tubs of Ardex EG8 - approx £70 + good grout cutter for multi tool £40) and 2 days of work vs tanking and re-tiling will cost me approx £500 that's if I don't brake any tiles + I estimate 7-8 days of work. Re-grouting may be worth trying but only if there is a good chance of success.

 

[DP Tiling]

I hear you, but it might be a false economy.
Water damage is a costly problem.

That said, we do not live in an ideal world and sometimes needs must.

 

[WetSaw]

How big is the roof? EPDM membrane an option?

 

[Unregistered]

How big is the roof? EPDM membrane an option?

EPDM is not an option. It's a terrace that is being used as a little garden in summer. I know EPDM is a good solution but in my opinion for roofs that are not being used.

 

[widler]

SBR won't make it waterproof..

SBR is used a s a water proofer in external render and internal DPM dave.
But your right, it won't make it waterproof.
Now the whole story has come out, RIP it up, re do it, waterproof the substrate and re tile, regrouting is not gonna waterproof it .

 

[Tile seller]

I had a sample of Mapei mape elastic through today and thought of this post.

 

[Dave]

SBR is used a s a water proofer in external render and internal DPM dave.
But your right, it won't make it waterproof.
Now the whole story has come out, RIP it up, re do it, waterproof the substrate and re tile, regrouting is not gonna waterproof it .

more of a water repeller than proofer. 🙂..

 

[Diamond Pool Finishers]

i would say it depends on the ratio of sbr in the render as to the percentage of waterproofing !