Cracks in Grout

[ja1736]

Hi, this is my first time posting on here so please bear with me as I don't know much about DIY.

This time last year we had cracks in the grout, so had a tiler come in February to lay new tiles in the bathroom. Under the floor tiles had been hardboard, which has quite a fix of flex, but the tiler said that this would be fine to lay new tiles on.

He used Weber joint pro which is meant to be flexible, but the grout started to crack again within a few months. Funnily enough I'm now unable to contact the tiler. I do have some of the weber joint pro remaining although don't know if its worth using.

My hunch is that there's a problem with the flooring, but due to the cost of getting the bathroom done last time, I'm hoping there might be some way of redoing the grout without having to take up the newly laid floor tiles.

Can anyone tell me whether weber joint pro is a good brand, or whether I should try a different brand. And whether it might be ok to fill in the grout, and what I should use.

Many Thanks for your time,
Jenny

 

[footprints]

I'm no tiler but as I undestand it you need pretty thick ( ideally waterproof) plywood under the tiles no matter how flexible the adhesive is if it is just on hardboard you are on a hiding to nothing.

Have a look at this old thread.

//www.diynot.com/forums/viewtopic.php?t=37375

 

[ja1736]

Thanks for the link to this. I can see that this is what should have been, had the tiler provided proper advice at the time, before the tiles were laid.

However, having spent quite a bit on tiles and having them laid, I'm hoping to find a way of making do with the hardwood flooring. We're planning on putting the house on the market in the next year, so I was hoping that there might be more of a quick fix solution.

In your opinion is there no way of getting the grout to hold with a hardboard floor over the wooden floorboards?

Thanks,
Jenny

 

[footprints]

I would like to say yes but I can't see any other option than a quick re-grout before selling (and we can wait for the post "I have bought a house and the tile grouting in the bathroom....."), keep an eye on the forum maybe some of the professional tilers on here can suggest a work around to get you out of trouble.
Regards,
footprints

 

[ja1736]

Thanks, we'll have to have a think about what to do!

 

[Terry7556]

ive been reading this with interest as ive got the same problem in my nephews bathroom
the problem is flexing in the wooden floor and the grout has cracked
i have relayed 50% of the tiles using 2 part adhesive (latex) as the plywood put down is too thin, 4mm on floorboards, 18 inch joist span, no noggins on an 7 foot span
i should have put my foot down and insisted, either 18mm wbp ply or backa board but too late now
ive asked him to consider black mastic instead of black grout
i dont like the situation but like you realisle now that you never stop learning
at least ive learned that 2 part adhesive isnt as bad or as costly as i thought

 

[jrh14]

Hello Jenny,
The problem isn't with the grout, it's your flooring. Before installing any tiles you need a solid foundation.
It would be a waste of time and money to replace the grout as it will only crack again over time.
Your best option and sadly most expensive would be to remove the tiles and start over.
I do recommend using Schlüter Ditra uncoupling membrane under the tiles. This will absorb any flex in the floor due to seasonal variations that may cause grout and tiles to crack.
I hope this helps.