Bathroom floor grout cracking

[bluevin123]

Hi,
Tiled a bathroom floor a couple of weeks ago for a customer. Plyed it out first with 12mm ply,primed it,used flexi addy and flexi grout and screwed down every 12 inches.
Few days later went back because the grout was cracking in places.
we went back and put more in,but last Friday he rang and said its cracking again.
So we going round tomorrow...Gonna get the old grout out and add GT1 to the grout mix to make it more flexilble and pour it in the gaps, apparently if we make it quite wet,it will go under the tile to fill any voids as well,if any..been advised by a skilled tiler to screw down every 4-6 inches for future jobs ,NOT 12.
Just hope this sorts it out,would hate to go back and rip it up,oh yeah they are porclain as well.
Does what I intend to do sound ok with you guys?
Cheers.
Vinnie.

[charlie1]

Did you prime the plywood before you tiled bluevin123?

[enduro]

Was the adhesive recommended for porcelain, i only use Bal porcelbond flexible addy.

[bluevin123]

Cheers guys,Yeah I primed the ply before I tiled,and the addy was for Porclain.
Cheers.
Vin.

[TilingLogistics]

What grout exactly did you use the first time? How wide are the grout joints?

You cannot modify an already Modified grout it will go like chewing gum. If you ring BAL or Mapei both their tech helplines will confirm this so you will have to slightly over modify one of their unmodified grouts

Kev

[Branty]

You need to fix the ply every 300mm centres. If the joists are 400mm spans, you need to add noggins. The ply should be 15mm min.

[bluevin123]

Hi Kev,it was Bal Wide Gout joint and the grout line is 3mm.
Cheers.
Vin.

[whitebeam]

Would have used Bal superflex wide joint grout

[Dave]

Hi Kev,it was Bal Wide Gout joint and the grout line is 3mm.
Cheers.
Vin.

So you used standard grout then.....?

[TilingLogistics]

Hi Kev,it was Bal Wide Gout joint and the grout line is 3mm.
Cheers.
Vin.

So as Dave said it wasn't flexi then I wouldn't bother modifying it get a good Bal Flex grout or a Mapei rake out the old stuff and regrout

Kev

[bluevin123]

Sorry guys I did use a flexi grout,as stated in my first post.
Been around there today and there was only about six inches to regrout.
When the bloke rang he made out it was all cracking,and us thinking it might have to be ripped up.
Well anyway fingers crossed it stays ok.
Cheers for your help .
Vin.

[Sully]

You need to fix the ply every 300mm centres. If the joists are 400mm spans, you need to add noggins. The ply should be 15mm min.

There in may lay the problem

Hello? Anyone else at home ? Why we discussing grout?

[Branty]

But he has used 12mm ply.
Even if he had used flexi grout, the chances are it could fail.
Is it really screwed into the joists every 300mm?

[TilingLogistics]

But he has used 12mm ply.
Even if he had used flexi grout, the chances are it could fail.
Is it really screwed into the joists every 300mm?

Danny,

I agree with you completely! It's been done wrong but he may get away with regrouting it???

Kev

[Branty]

Danny,

I agree with you completely! It's been done wrong but he may get away with regrouting it???

Kev

But the correct reply would be to tell him everywhere he has gone wrong.
If he went ahead and regrouted with a W/J grout and AD1, and that cracked. He then Came back on here for more advice, and you then tell him his ply was not thick enough. Would refund him his money for the extra grout and labour?

[TilingLogistics]

But the correct reply would be to tell him everywhere he has gone wrong.
If he went ahead and regrouted with a W/J grout and AD1, and that cracked. He then Came back on here for more advice, and you then tell him his ply was not thick enough. Would refund him his money for the extra grout and labour?

Danny,

His initial query was he intended to modify an already modified grout. I pointed out he couldn't. Ultimately it was only 6" of grout cracking. If I told him everything that was wrong he would have to rip up the whole thing. People come on here because they are looking for answers to solve their problems. If I went your route virtually every job would have to be redone. You have already said in other posts you are seeing this daily. How many rip it up and do it again???

Kev

[Branty]

Danny,

His initial query was he intended to modify an already modified grout. I pointed out he couldn't. Ultimately it was only 6" of grout cracking. If I told him everything that was wrong he would have to rip up the whole thing. People come on here because they are looking for answers to solve their problems. If I went your route virtually every job would have to be redone. You have already said in other posts you are seeing this daily. How many rip it up and do it again???

Kev

In this instance, if I was called out to this job, that is what would need to be done, and that is the advice, as a BAL employee I'd have to give.
So that's the advice I gave the guy.
As a professional giving advice to people that are looking for it, then that too is the advice you have to give. If the floor needs to be ripped up, then that is what has to happen.
I didn't even mention the fact he has voids under his floor, which should be solid bed fixed.
If some one asks for advice on putting a job right, I give it. As I said, if this guy had spent a few quid regrouting, and he came back here next week saying his floor grout had cracked again, what would you say to him?

[brian c]

as the song says Branty....'rip it up and start again'

IMO - you both have valid points but i think vinnie was looking for the quick fix in the meantime.

[Branty]

as the song says Branty....'rip it up and start again'

IMO - you both have valid points but i think vinnie was looking for the quick fix in the meantime.

I agree Brian.
But when you do that, its important to point out what probably is the underlying problem. That way you're giving the overal picture, and let the person decide what he wants with all the facts. I was just trying to cover all the bases on this post. Not just repeat what other people have already said.

[brian c]

yes m8 i understand exactly what you are saying and thanks again for explaining in full as im sure some of the new guys will take heid of the advice given.

[Dave]

Cheers danny..good advice as usual.....like you say better to do it right than do it again and again...

[Branty]

Cheers danny..good advice as usual.....like you say better to do it right than do it again and again...

Cheers Dave.
I live in the real world and know sometimes what you have to do and what you can afford to do are not always compatible.
Since working for BAL I've realised you need to give the full facts or it might bite you on the bum.

[Dave]

I bet your new job danny has opened your eyes alot to what fixers get up to...

[Branty]

It certainly has Dave.

[deanotile]

In my humble opinion the advice given to tilers today should be do not tile directly on to plywood sub-straights. There are more than enough products out there that can do the job. You are risking a failure if you tile on to wood in the best of circumstances. Even if you have used 18mm ply and screwed at 6 inch centres and primed the under side and the edges of the wood and screwed the tong and groove floorboards to ensure there rigidity. You can even go as far as to ensure the joists are free from movement. You can do all this and still get a failure. Wood is unpredictable.

[graham31]

In my humble opinion the advice given to tilers today should be do not tile directly on to plywood sub-straights. There are more than enough products out there that can do the job. You are risking a failure if you tile on to wood in the best of circumstances. Even if you have used 18mm ply and screwed at 6 inch centres and primed the under side and the edges of the wood and screwed the tong and groove floorboards to ensure there rigidity. You can even go as far as to ensure the joists are free from movement. You can do all this and still get a failure. Wood is unpredictable.

Yes see your point,but is this not changing what every tiler has been taught over the years?

[DEtileD]

In most cases 18mm is recommended. Quite sure the recommendations is to screw it down a little closer.

[DEtileD]

hmmm sorry didnt see the last page of comments before i replied.....hand in hornets nest...

[Branty]

hmmm sorry didnt see the last page of comments before i replied.....hand in hornets nest...

Always good to have it confirmed.

[deanotile]

Yes see your point,but is this not changing what every tiler has been taught over the years?

Yes but change is a good thing in this case.