600mm polished porcelaine tiles

[Rich]

I would keep the grout flush with the top of the tile. As for the joint size, thats totally down to the customer! And if the floor isnt flat and level, you will be able to get away with a hell of a lot more with a 5mm joint seeing as they are square edged tiles. As peckers said, it might help you to make the grout a bit stiffer than usual and if you still end up with shallow joints, it would be worth grouting over it again to get them flush (if you have time that is).

 

[sibleytiling]

the customer is going to seal the tiles but they want to do it b4 i grout as the are a fair way from my base what is general opinion on me grouting and them sealing after the grout is done.
BTW they are now going to have a 2mm grout joint :hurray:

 

[Stan001]

I love that everyone has an opinion on minimum grout widths and yet nobody seems to refer to the standards …. BS5385 Part 3 states a minimum of 3mm on floors clauses 23.5 and 24.
It’s the only standard we have to work to and I guess its there for a reason, namely failure if you don’t build / set tile to that standard then you have your own professional opinion top fall back on rather than the industries (if I knew your tile size and room size Id be able to tell you how much additional stress you are imparting into your floor by going to your chosen size … ) – and you will find if you look in the smallprint that companies such as BAL (and no doubt others) have 25 year guarantees if you use the correct specified product in accordance with the specifications (in the case of their grout BAL will point you directly to the BS sections just mentioned in their tec sheets!).

I don’t work to opinions – I work to spec. for exactly these reasons.
(I know Weber has a similar stance after long conversations with them too)

… so my advice is follow the industries advice …. 3mm min !

(unless you find an over-riding spec that says otherwise, which is always possible, in which case go with that / let me know and I happily stand corrected)

 

[marbleman]

you got it BSI tried and tested over years

 

[Sean fsy]

B&Q 600mm polished porcelain with 3mm joints, customer sealed them first befor i fitted them:

 

[Sean fsy]

you say black tiles so i imagine they want black,charcoal grout, if this is the case i would let them seal them first as staining might be a problem if not sealed prior.