Floor tiles grout line minimum reequired size.

[lukeb]

Hi Guys.
Just quoted for 20m2 of kitchen floor(polished porcelain 330x330)
Customer specify that he wants to keep grout lines to maximum 2mm.
BS require minimum 3mm spacing(I think)any suggestions appreciated.
Funny enough always use 4mm so I`m asking for Your professional opinion.
Sub floor is chipboard witch 12mm ply(it was prepared for tiling by builder???)
Will use cement bord on the top of it.

So what minimum spacing can you recomend======= ??????

:bigear:

 

[Ian]

Minimum 3mm for me, i wouldn't go don to 2mm on a wooden substrate.

 

[Mike Mike]

12mm ply does not comply with British Standards (15mm, which means 18mm because 15mm does not exist). Tile this job with 2mm or 22mm grout lines and when it all goes wrong you'll have to pay to rip it out and do it again. Walk away and tell him to get the "builder" to tile the floor for him instead...

 

[AliGage]

If you're boarding over with hardibacker then i don't think you'll have a problem using 2mm. I've done this before as requested by customers and never and an issue. I think i used bal microflex grout.

 

[lukeb]

12mm ply does not comply with British Standards (15mm, which means 18mm because 15mm does not exist). Tile this job with 2mm or 22mm grout lines and when it all goes wrong you'll have to pay to rip it out and do it again. Walk away and tell him to get the "builder" to tile the floor for him instead...

As I said in the post -will use cement board over existing subfloor(chipbo`d and 12mm ply) so im not tiling directly onto 12mmp ply,am I?
So why do you think it will fail.
I`m pretty sure that most of the tilers in here will do the same maybe some will use decoupling membrane for peace of mind.

what will be your ideal method??????

 

[Gall.B]

Have done the Decoupling over 12mm ply thing after discussing with customer

Would not be willing to go down to 2mm though especialy if the tile size's are not very regular.

Usally 3-4mm for me depending on substrate or tile.

 

[steve187]

3mm for me, make sure everything is well screwed down, builders never put enough screws in. and check well for any deflection.

 

[Mike Mike]

Sorry Lukeb, I did not spot that you said "Will use cement bord on the top of it".

 

[Mike]

3mm for me, make sure everything is well screwed down, builders never put enough screws in. and check well for any deflection.

steve's right but be careful screwing 'blind' if you don't know whats under the existing boards e.g. pipes or cables

 

[Drastik Lee]

i would deffo go with 3mm or even 4mm in my opinion not only would 2mm look slightly odd but if the tiles are not true itll make it slightly harder lining up also i would make sure the ply the builder put down was sound and use bal flexi possibly with bal sbr bond part mixed to give peace of mind

 

[lukeb]

Thanks Guys for all the suggestions.
Will go for 3mm.
Builder wasn`t to bad ply has been glued and screwed every 150mm.Point out Ditra to the Client but seems to be to much for him so passed on idea.
So looks like someone is working this weekend:smilewinkgrin:

 

[Drastik Lee]

Hope it goes well !

 

[Rich]

I love it when a plan comes together

Not that it matters now but I wouldn't go with 2mm, get asked all the time and have to explain that its 3mm min.