Problems re-grouting shower area

[Poorah]

Hi all,

I've a problem patch of tiling where the grouting just does not want to stick. It's in my shower and when the grouting falls off, I leave the shower area to dry for a couple of days, grout and then leave to dry for a couple of days. After the first shower the grout starts to fall out almost immediately. I've re-grouted loads of times, but for some reason the additional grout does not want to stay, it's driving me mental!

Does anyone have any suggestions or ideas? What kind of prep work should I undertake? Is there a particualr brand of grout that might help? All advice greatly recieved.

Thanks

P.S. I bought the house as a new build and even the builders have had issues with the grouting.

 

[Colour Republic]

Spooky, what brand of grout are you using and where did you buy it from?

 

[david campbell]

never heard anything like it before!
what type of tiles are they?
my only conclusion is they have been sealed on the sides but that would only be polished porcelain and natural stones

 

[DHTiling]

You should be leaving it longer than a couple days before using the shower..

 

[Colour Republic]

You should be leaving it longer than a couple days before using the shower..

I agree but still to wash out is a bit much unless the shower has the pressure of a jet wash:yikes:

 

[DHTiling]

Wet substrate can cause weak drying.... porous biscuit could be sucking moisture leaving a crumbly grout.. A few reasons really...

A polymer modified should be tried..and left the correct time to dry and gain strength..