Grout not sticking

RATM

A couple of weeks ago I re-grouted the bathroom tiles on the floor, mainly because the grout had come away from one tile in the centre of the bathroom and it was beginning to happen others around it too.

Anyway I cleaned out all the old grout with a carbon saw and then re-grouted. But about 3-4 days later the grout on the tile in the centre begun to crack and dissappear again and then the same begun to happen on the other tiles around it. So I re-grouted a second time but now a week later it has happened again.

Has anyone any ideas what the problem might be ? To me it might be significant that it is happening from the centre tile outwards- might I be suffering from some sort of mold/damp underneath the tile ? Bathroom has an extract fan but no window, its in an apartment. The only other thing I can think of is that if there is a specific grout for floors I used one that is more suited to walls ?

TonyStark

RATM wrote: »

A couple of weeks ago I re-grouted the bathroom tiles on the floor, mainly because the grout had come away from one tile in the centre of the bathroom and it was beginning to happen others around it too.

Anyway I cleaned out all the old grout with a carbon saw and then re-grouted. But about 3-4 days later the grout on the tile in the centre begun to crack and dissappear again and then the same begun to happen on the other tiles around it. So I re-grouted a second time but now a week later it has happened again.

Has anyone any ideas what the problem might be ? To me it might be significant that it is happening from the centre tile outwards- might I be suffering from some sort of mold/damp underneath the tile ? Bathroom has an extract fan but no window, its in an apartment. The only other thing I can think of is that if there is a specific grout for floors I used one that is more suited to walls ?

Upstairs or downstairs?

samdavis

Did you use flexible grout? If the tiles are laid onto marine ply then you definitely need flexible grout. Was it a new bag of grout or have you used the same one each time?

TonyStark

samdavis wrote: »

Did you use flexible grout? If the tiles are laid onto marine ply then you definitely need flexible grout. Was it a new bag of grout or have you used the same one each time?

+1 this is the approach I used with the upstairs in our house. Plenty of screws to keep the floorboards in place.

RATM

TonyStark wrote: »

Upstairs or downstairs?

I'm on the first floor in an apartment building

samdavis wrote: »

Did you use flexible grout? If the tiles are laid onto marine ply then you definitely need flexible grout. Was it a new bag of grout or have you used the same one each time?

I'm not sure if it was flexible or not, what advantage does flexible grout offer ?
The first bag I used was Unibond grout, the second I bought was Homebase's own brand. I only used a little water and mixed it fairly thick.

samdavis

If you tile onto marine ply, (standard practise if you're on the first floor) you need flexible adhesive and grout, there is a bit of give with marine ply/floorboards, even slight movement will mean your grout will crack if it's not flexible. The only time you would use regular adhesive and grout is when you're tiling onto a concrete floor, ie. no give whatsoever. Find yourself a tile shop that sells BAL products, they have a grout called 'superflex', it costs 13 or 14 euro for a 3.5kg bag. Instructions on the back of the bag!

RATM

samdavis wrote: »

If you tile onto marine ply, (standard practise if you're on the first floor) you need flexible adhesive and grout, there is a bit of give with marine ply/floorboards, even slight movement will mean your grout will crack if it's not flexible. The only time you would use regular adhesive and grout is when you're tiling onto a concrete floor, ie. no give whatsoever. Find yourself a tile shop that sells BAL products, they have a grout called 'superflex', it costs 13 or 14 euro for a 3.5kg bag. Instructions on the back of the bag!

Thanks for that=)

I don't suppose it is available in any smaller sizes? I'm literally doing 4 sqm so only need about 500g. No harm if it isn't, just wondering. Also is BAL Superflex carried by any of the sheds like Woodies, B&Q or Homebase ?

samdavis

Don't know where you're based, if you go to the Bal website, they have a list of stockists. Don't think it comes in smaller sizes, the 3.5 kg bag is the smallest we stock in our shop, regards, Sam

RATM

Thanks Sam, I'll pick that up and hopefully it'll solve my problem