Do you have to grout?

[garethg]

Been looking at some large (600mmx600mm) grey porcelain tiles in a not-so-local DIY store.
You need to seal them before and after laying them, that is fine.
However, being grey, I am not sure what colour grout would look correct between the tiles, and the tiles look better (I think these ones do), without a gap.
So do you /have/ to use spacers when laying tiles and then fill the space with grout? (BTW. the sticky post has 'tent away from the wall' under the floor section). 5mm seems a tad excessive!

If it makes a difference, I intend on leveling the floor using insulated board, an underfloor heating mat then adhesive (flexible, not decided which one yet). Area to be covered is roughly 12 tiles by 3 tiles (and a very small bit).

 

[jefoss]

things move in different temperatures. if you dont grout tiles will do "do an everest"

 

[DoctorC]

close butt jointed large format tiles are reasonably common on the continent, however, BS suggests that 2 or 3mm is the minimum allowed for in the UK.

we have just had 600 x 600 tiles laid with a 3mm joint. looks good.

 

[gcol]

....however, BS suggests that 2 or 3mm is the minimum allowed for in the UK.

I don't have a copy of the relevant British Standard (BS5385) and I don't know anyone that does. Do you know anyone with a copy? (It's £150 a copy you know.) Is it mentioned in BS5385-1 or 3 or both?

Either standard, is just a code of conduct, which means that it's recommendation only. You only need to be adhering to it if you're an ISO9001 company. (Personally, I don't know one tiler that has the kitemark.)

So, just out of interest, which is the minimum, 2 or 3mm? (I doubt it says both.) Also, is this just for regular ceramic or does it cover natural stone too? Is this just for floors or does the same go for walls?

 

[garethg]

The wiki stated 5mm, but I took a risk (and mainly because I didn't really want a gap, and the shop I was at didn't have 5mm in stock), and got 4mm in the end. Just spent the weekend raising the old tiles (around 2/3rds of the way through, and my arms ache).
I got some grey grout in the end. It will probably start off a lighter shade than the tiles, but hopefully dull over time.
thanks for the responses. (and I wish I had seen the comment about using a floor sander to take up the old adhesive).
Gareth

 

[DoctorC]

I have access to British Standards

BS 5385 - 3 says "not less than 3mm" in section 7.1.5

 

[gcol]

4mm is fine. It looks better to go smaller than larger. The smaller you go, the harder it is to get it looking right (any slight difference in gap is more noticeable). Also, any unevenness (height-wise) of tiles is more noticeable the closer they are together too.
You can get some 7mm spacers, but these make the floor look terrible.
3mm spacers can look very smart on a floor, but as I mentioned, are a little more difficult to get looking right.

 

[gcol]

I have access to British Standards

BS 5385 - 3 says "not less than 3mm" in section 7.1.5

OK. How do have access (if you don't mind me asking)?
So, is that just for floors? What about walls?