Required gap for 600x600 porcelain tiles and other questions

Guys hi,

Looking for some advice, I have asked a tiler for a quote to fit some 600x600 rectified polished porcelain tiles (pale cream marble look) to the entire ground floor of our house. I have a couple of questions that I asked him that I would like a second opinion on.

1) The tile supplier said that the tiles look best 'without any joint' (I assume he means butting tiles together completely) as they just form a single expanse of marble look floor. He said that if a gap was required then it should be 3mm absolute maximum ideally 1-2mm.

The tiler said they must not be butted together as this allows nothing for tolerance or imperfections in floor. He thought 2-3mm may be achievable.

QUESTIONS:
What is a reasonable gap and would look best?
Do the tiles always need grouting even if there is no 'gap'?
Do pro tiler usually use spacers on this size and type of floor tile?

2)Some of the floor is at a different level because it has woodblock floor (the small rectangular blocks arranged in groups of 4 to make squareswhich alternate at 90 degrees) this is made of individual blocks that are bonded with bitumen to the original screed. The wood is sound and very level. A few rooms are basically just screed - it is prob 70% woodblock, 30% screed.

Tiler says best bet is to raise screed with screwed, plugged ply (I can do it or he has a chippie who will do it). He thinks that the sound floor will make a very good base for the tiles with a flexi adhesive. He also says removing the woodblock will make a mess of the screed and it would need levelling = more time and money.

QUESTIONS:
Does this sound like the most sensibile approach?
Some of the screed floor is highe than other parts (something to do with rescreed after kitchen flood) I am worried that in the kitchen there will not be room to lay a thick enough ply (it seems 18mm is standard) if the height difference is smaller than 18mm what are the options? How much height difference between two floors can be managed with a different bed of adhesive?


Thanks in advance
Tim

As these are porcelain tiles you do need the gap to allow for variation in tile size. In supermarkets etc where they use marble etc these would be ground and honed after fixing. 1 to 2 mm is brave with these size tiles. I suggest these are fitted in a brick type overlapping pattern to allow for variance so the grout joints can be minimisied.
Some polished porcerlain tiles need sealing before fixing so check out the porosity of the tile before fixing. You can do this by applying water to the surface of the tiles and see if its absorbed. Also check out the sides of the tile with the same test. If water is absorbed then best to seal before fixing.

[quote=t5_nel;6829]Guys hi,

Looking for some advice, I have asked a tiler for a quote to fit some 600x600 rectified polished porcelain tiles (pale cream marble look) to the entire ground floor of our house. I have a couple of questions that I asked him that I would like a second opinion on.

1) The tile supplier said that the tiles look best 'without any joint' (I assume he means butting tiles together completely) as they just form a single expanse of marble look floor. He said that if a gap was required then it should be 3mm absolute maximum ideally 1-2mm.

The tiler said they must not be butted together as this allows nothing for tolerance or imperfections in floor. He thought 2-3mm may be achievable.

QUESTIONS:
What is a reasonable gap and would look best? [COLOR=red]2 TO 3 MM MAX[/COLOR]
Do the tiles always need grouting even if there is no 'gap'? [COLOR=red]ALWAYS[/COLOR]
Do pro tiler usually use spacers on this size and type of floor tile? [COLOR=red]PROFESIONAL TILERS ALWAYS USE SPACERS[/COLOR]

2)Some of the floor is at a different level because it has woodblock floor (the small rectangular blocks arranged in groups of 4 to make squareswhich alternate at 90 degrees) this is made of individual blocks that are bonded with bitumen to the original screed. The wood is sound and very level. A few rooms are basically just screed - it is prob 70% woodblock, 30% screed.
[COLOR=red]NOT TOO SURE ABOUT TILING DIRECT TO A VARNISHED BLOCK FLOOR,AS YOUR NOT STICKING TO THE ACTUAL SUBSTRATE,ONLY TO THE VARNISH,I THINK MAYBE SANDING THE FLOOR BACK TO ITS RAW STATE TO GET A BETTER "KEY" IS ADVISABLE HERE, COAT WITH ARDEX P 51 PRIMER, FIX WITH ARDEX 7001 FLOOR ADHESIVE,THAT SHOULD DO THE JOB NO PROBLEM, YOU MUST MAKE SURE THERE ARE NO SECTION OF THE WOODEN FLOOR HAS DE-LAMINATED FROM THE SUBSTRATE[/COLOR]. [COLOR=magenta]ALTERNATIVELY COULD IF YOU WANTED TO, USE SCHLUTER DITRA MATTING OVER THE WHOLE FLOOR AREA,THIS IS ALSO ANOTHER EFFECTIVE WAY OF TILING ONTO SUBSTRATES THAT MIGHT BE SUBJECT MOVEMENT,EXPANSION,ITS QUITE EXPENSIVE BUT IS AN EXCELLENT PRODUCT![/COLOR]
[URL="http://www.schluter.com/6_1_ditra.aspx"]Schluter-DITRA - Schluter-Systems[/URL]

Tiler says best bet is to raise screed with screwed, plugged ply (I can do it or he has a chippie who will do it). He thinks that the sound floor will make a very good base for the tiles with a flexi adhesive. He also says removing the woodblock will make a mess of the screed and it would need levelling = more time and money.

QUESTIONS:
Does this sound like the most sensibile approach? [COLOR=red]YES,CHEAPEST WAY DEFINATELY,IT MUST BE SCREWED AND GLUD AT 300 mm CENTRES ,PRIMED AS PREVIOUSLY STATED,WEDI BOARD IS A BETTER PRODUCT,BUT ITS ALL DOWN TO COST AGAIN[/COLOR]
Some of the screed floor is highe than other parts (something to do with rescreed after kitchen flood) I am worried that in the kitchen there will not be room to lay a thick enough ply (it seems 18mm is standard) if the height difference is smaller than 18mm what are the options? How much height difference between two floors can be managed with a different bed of adhesive?[COLOR=red]WEDI BOARD IS A BETTER PRODUCT,AVAILABLE IN A RANGE OF THICKNESSES,YOU CAN FIX IT WITH FLOOR ADHESIVE,AND BED IT UP OR DOWN TO THE REQUIRED HEIGHT,MAKING SURE NO VOIDS ARE LEFT BELOW THE BOARD WHEN FIXING IT, RECENTLY TILED AN ONIELS IRISH BAR 300 SQ MTRS ,THE FLOOR HAD TO RAISED BY 12MM TO ACCOMODATE 2 LEVELS FLOORING,WEDI BOARD WAS AN EXCELLENT FAST TRACK PRODUCT IN THIS SITUATION,ITS NOT A CHEAP PRODUCT BUT DOES THE JOB IT IS MADE TO DO,EASY TO CUT AND INSTALL,MAKE SURE ALL JOINTS ARE TAPED,AND LAY IT BRICK BOND FASHION[/COLOR]



..
:)

Thanks in advance
Tim[/quote]

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[url=http://www.schluter.com/5372.aspx]Wood Substrate - Over Unoccupied Space - Schluter-Systems[/url]

some more information for you regarding plyboarded floors, and the application ditra matting is used for ,hope this helps

[

1) The tile supplier said that the tiles look best 'without any joint' (I assume he means butting tiles together completely) as they just form a single expanse of marble look floor. He said that if a gap was required then it should be 3mm absolute maximum ideally 1-2mm.

The tiler said they must not be butted together as this allows nothing for tolerance or imperfections in floor. He thought 2-3mm may be achievable.


The British Standard is 3mm minimum, to allow for expansion / movement, so the tiler is almost correct :)

Infact, just reading through Epoxy Pete's post, its bang on so I will save my breath. lol

Don't forget, you can use Self Leveller with chippings in it to raise floors higher than 6mm. :)

Epoxy Pete is bang on -
The only thing I would like to add is that ...........

Although 2 or 3mm minimum is the standard - care should be taken.
The only way to ensure near perfect tile sizes is to purchase rectified Porcelain. Any others can have an allowable tolerance in size that can make using a 2 or 3 mm spacer nigh on impossible ( dependant upon manufacturer, country of origin & who was on the machine at time of manufacture ). You may end up needing bigger spacers. I recently undertook a job - tiles were 600 x 600 porcelain - tiles differed in size anywhere between 1 and 3mm - job was a nightmare. Tiles were not rectified.

Thanks for the advice guys.:)

I will speak to the tiler about making sure that the blocks are roughed up to provide a key (think I can do this with belt sander & coarse paper). I will also ask what adhesive he thinks he will use.

At my previous house ditra was used in a utility room where substrate was suspended green (waterproof) chipboard. The result was good but the tiler told me it cost a lot per m2. How much cost would this add normally (parts & labour) to a job per m2 - just a ballpark is fine.

ditra matting at a good trade price is about £8.50 sq mtr plus vat... glue required to stick it down about 40.00 + plus vat
30 sq mtrs on a roll..... 1 tub of glue(large) is sufficient to do the job, mapei rollcoll or any acrlylic water based flooring adhesive works well,lee floor stock or similar outlet will be able to supply it.dont use anything else to fix it down with !,once the tiles are down on the ditra,they are well and truly stuck..:)

[quote=t5_nel;7000]Thanks for the advice guys.:)

I will speak to the tiler about making sure that the blocks are roughed up to provide a key (think I can do this with belt sander & coarse paper). I will also ask what adhesive he thinks he will use.

At my previous house ditra was used in a utility room where substrate was suspended green (waterproof) chipboard. The result was good but the tiler told me it cost a lot per m2. How much cost would this add normally (parts & labour) to a job per m2 - just a ballpark is fine.[/quote]


[COLOR=red]you can lay the matting yourself its so easy,a good blade in your stanley knife,and a floor layers trowel 1 to 2 mm notch should do fine,you dont have to be too accurate with the cutting around door casings etc, as long as its covered with the matting you should be fine[/COLOR]