grouting problem

[lee.chris80]

im a beginner whos just tiled my bathroom but the grout is starting to have small cracks in it in 1 or 2 places, not all over!
i primed 6mm ply underneath
no more nails and screwed it down at 300 centres
then layed the tiles on unibond advance floor adhesive
waited 24hrs then grouted up with unibond quick set
sponged off and it looked perfect
until the following day when the tiny crumbling appeared. i should of used both flex adhesive and grout , is this why its cracking. any advice anyone?
cheers

 

[Gazzer]

6mm ply is no good. Sorry.

 

[nybor62]

as above 6mm no good

 

[White Room]

6mm ply and no more nails, there must be hollow areas under the ply

 

[lee.chris80]

if i used any thicker ply there would of been a step, thats why i used 6mm, i live in a new house and members on ere have reccamended take up the floor boards first then lye 15mm or 18mm ply? is this true?

 

[Spud]

if i used any thicker ply there would of been a step, thats why i used 6mm, i live in a new house and members on ere have reccamended take up the floor boards first then lye 15mm or 18mm ply? is this true?

why didnt you take their advice may I ask ?

 

[lee.chris80]

i didnt read the comments until i came on here for advice after id finished the bathroom.

 

[faithhealer]

6mm backer board might have been an option chris

 

[lee.chris80]

hi there faithhealer, i c ur from sedgy, im only over kelloe, hows the little place goin ova there?. if the grouting continues to crack i might give the hardi-backer a go, dont wanna rip up floor boarding.

 

[Mike]

and decent cement based flexi adhesive. no more nails is rubbish, better off with gripfill and 150 to 200 centres

 

[easyt]

Maybe put it down to experience and redo. Just a thought but I tiled a bathroom upstairs in previous house. Took up boards and laid 18mm ply but left an area under a vanity unit uncovered. This meant if I removed kicker and base shelf I could access electric cables and pull through if necessary. I also relocated a junction box to that area. I replace some wiring to a kitchen light beneath the boarding to provide sufficient slack to pull down if necessary. You might be advised, if you redo, to look at what is under those floorboards in case you require access.

Easy T

I'm no expert but I think if I was overlaying with thinner board I would have screwed down.

 

[DHTiling]

hi there faithhealer, i c ur from sedgy, im only over kelloe, hows the little place goin ova there?. if the grouting continues to crack i might give the hardi-backer a go, dont wanna rip up floor boarding.

I am near you as well..N'aycliffe..

6mm ply is not stable enough to tile too.. and probs the adhesive /grout might be an issue as well..

Maybe John or i could point you towards getting the proper gear at a good price.

 

[paul flight]

:welcome: as above this floor will come up over time so you may as well start again!!!

 

[lee.chris80]

thanks lads, il give it a week or so to c how it developes and decide wether to rip it up or not.

 

[faithhealer]

I am near you as well..N'aycliffe..

6mm ply is not stable enough to tile too.. and probs the adhesive /grout might be an issue as well..

Maybe John or i could point you towards getting the proper gear at a good price.

as dave says chris, just shout if you want pointing in the right direction