Cracked Grout

[spx]

Hi guys,

Any advice on grouting - the grout in my shower keeps cracking and I'm concerned it's going to allow water seepage.

I used 20mm ply board water proof and flexable adhesive and grout and it has still cracked. But only in the shower!

Any advise on weather it may be the steam or something I have started to notice mold accumilating - shower has been built approx 6 months.

 

[jbonding]

is it cracking in each joint or just in the corner?

 

[spx]

Down the joints all vertical no horizontal cracks.

 

[Jasonb]

The grout is not impervious to water so moisture has got into the ply and it has swollen due to the moisture.

You should not really have used ply. Best to rip it all out, use aquapanel in place of the ply then tank with something like BAL WP1 and then retile.

Jason

 

[spx]

Bugger. Slight problem, got the tiles from tiles R us closing down sale. No more stock. Sh*t. Any other advise?

 

[gcol]

What grout did you use?

 

[spx]

The tiles R us brand, flexable, waterproof - suitable for showers (apparently)

 

[gcol]

I've never used that. Was it pre-mixed or was it a powder to which you had to add water?

 

[spx]

It was the powder type that you mix with water.

 

[Softus]

The grout is not impervious to water so moisture has got into the ply and it has swollen due to the moisture.

How does that account for the fact that all the cracks are vertical?

You should not really have used ply.

There's nothing wrong with using plywood, as long as it's either WBP or marine.

If the the grout is cracking vertically then the tiles are moving horizontally, which means that the walls are moving. The answer? Stop the walls moving - next time you'll do this before you start tiling

 

[spx]

Actually I think you may have hit the nail on the head I have a cuboard outside the bathroom with a dryer on a shelve it could possible be the vibrations from it.

Strangely enough though it is the two walls that are furthest from the dryer that have the cracks!