Help!: Porcelain Floor Tiles - What trowel size and adhesive

[MartinH]

Morning all - help required.....

I am doing my first porcelain floor job next week , and the tiles I am laying are

Square gloss surface porcelain
Dimensions 440 mm x 440 mm
Depth 10mm

These are being laid on Marmox backerboard and I wanted advice as to the best notch-size trowel to use and the appropriate adhesive

Additionally I was going to use a Rubi 18mm gold scoring wheel for straight cutting, would that be sufficient or even too large a scoring wheel ?

Any help appreciated and any other tips to help with this job would be equally appreciated

Many thanks

Martin

[charlie1]

Hi Martin,10mm scoring wheel will do. How flat is the subloor? if good then i would use 10mm u notch trowel plus back skim the tile too!
Good luck

[charlie1]

I would also use kerraflex adhesive however you may prefer a slower setting one as these tiles will need to laid spot on level, if not then its very noticabile!

The tiles are polished porc, then must be layed 100 % flat to one another...
1, find highest spot in the floor (you can allways add adhesive but you cant reallt take floor away)...hope you follow!
2, After you set out, lay your tile where the highest spot is
3, On this first tile place a 1800 level and rotate it through 360 degres to ensure perfectly level and allow to set
4, Cary on tiling as normal placing the level over youe tiles and back buttering as required!

[jwatson]

rule of thumb is the larger the tile the larger the trowel 10mm should be surficiant as long as floor is suficiantly flat.(trowel needs to be a u notched one realy to get 100% coverage as of british standards on a floor)
my 10mm scoring wheel works just fine on polished porcelain. never tried using anything bigger realy.

[andy8758]

Hi Martin, I don't necessarily disagree with Charlie1's advice, but I notice you are laying onto Marmox backer board - if laid properly, Marmox will now give you a flat surface, and no further problems about "high spots" but always worth checking with spirit level as recommended by Charlie.

I also concur with Charlies U notch trowel advice - having said that there is a strong school of thought that square notch trowels will give you the best results - i.e. no lippage. In which case a 12mm square notch trowel is best to ensure the 100% coverage on tile with no lippage. In any event I always tend to recommend a wetter mix of adhesive as favoured in Europe, I find it much quicker to use and still avoid lippage, always provided you are not having to "build up" sections of floor which are not flat.

Good luck with the job.

[Daz]

Okay, the tiles are 10mm deep so I suggest no more than a 10mm trowel (I prefer square but there is no reason why a rounded notch won't give the desired results), always backskim the tiles with the flat edge of the trowel.

You shouldn't need to build out the tiles unless the floor must be 100% "bubble" level. I would normally aim for a flat floor (i.e. no lippage) with the area under toilet pan "bubbled".

I hope that helps & good luck.

Daz

[paul78]

id also double check if they need sealing, because if you grout them without checking you could be in trouble.

dry wipe pen test on an offcut should do it.

[TTT]

Personally any thing over 300x300 i use a 12mm trowel depending on the floor with that size tile id be testing to see if i could get full bed coverage with my 15mm trowel with out skimming. Always check polished porcelain needs sealing.