agwill

Hope someone can help me? I have received a floor tiling job to quote for which specifies Mapei adhesive and grout (Keraflex and Ultra colour). On the data sheet it says to use an n.5 notched trowel on mid size floor tiles and an n.6 on larger sizes. What size is an n.5 in mm? The spec says to use a 3mm solid bed. This seems rather thin to me?

brian c

welcome to the forums m8,as long as you use a suitable notched trowel that provides a thickness of 3 to 6 mm you will be fine.sometimes you need to back butter large tiles to ensure a solid bed.

tilermandan

dont worry about the spec to much in this case. i use an 8mm square notch on walls and a 10mm square notch on floors these i find are adequate for most jobs, but always check coverage randomly as tiling. you will need to make sure you are achieving no less than 65% coverage on walls and 100% on floors hope this helps.

Dave

Also if its showers or wetrooms then 100% on walls as well....

tiler burden

hi

its strange that alot of people use 10mm notched for floors, when many people claim you need a 10mm half round to achieve 100 perc coverage.

dont get me wrong, i am not critising anybody, it just gets confusing at times?

i was told 3mm for mosaics, 6mm/8mm notched for walls and 10mm radius trowel for floor tiling, and naturals on walls as well as back buttering.

makes you wonder why theres a 10mm and 12mm notched, if all of the above do the same job....

ed

tilermandan

10mm square notch 10mm half round the bed depth and coverage
is still the same surely? i think i gos down to preference at the end of the day really.six of one and all that!

tiler burden

no mate,

apparently the half round gives 100 percent and i think the notched achieves 70-80....if i am wrong please feel free anybody to correct me as i dont want to give out the wrong info

ed

Dave

Hi ed mate..

Just to clarify this for you mate....

Larger notch trowels are used with large format tiles and un-even substrates etc...but you will need to use thick bed adhesives as well...other wise the adhesives cant cope with the bed thickness... wot i mean by thick bed adhesives is these are the type which won,t shrink or slump whilst drying....i.e. BAL PTB...etc etc....there are other makes but this is just an example...

hope this helps... ..

BAL PTB (Pourable Thick Bed) Flexible

A highly polymer modified, flexible, rapid-setting, water-resistant, frost-resistant floor tile adhesive, especially suitable for fixing tiles, including fully vitrified and porcelain tiles to low porosity backgrounds and bases. Sulphate-resistant, cement-based, pourable, thick-bed solid-bed floor tile adhesive suitable for fixing ceramic tiles, quarries, natural stone and terrazzo in interior and exterior situations. Its consistency makes it particularly suitable for fixing large tiles and those with profiled backs. Back-buttering is not necessary. Suitable for use on concrete, cement:sand screeds, ceramic/quarry tile/terrazzo/hard natural stone, plywood overlay, vinyl tiles/sheet, mastic asphalt. BS EN 12004 C2F Adhesive

tilermandan

there is no wrong info mate.its all good advice your giving thanks for your input on the thread,at the end of the day i think your safe with either.

tiler burden

thanks for that dave ;0)

much appreciated as always. you can see where i am coming from with the confusion tho mate. you get so many people saying 10mm half round and even 20mm half round for larger heavy stones because they achieve 100 per etc etc, then some people say 10mm 12 mm but yet they apparently dont achieve 100 perc]

i'll stop waffling on now and go and see iif the wife is ready to give birth yet! on standby waiting for baby no 3!!!!!

cheers
ed

pps thanks to tilemandan, appreciate your advice too mate, all the best ;0)

Dave

If you want more coverage than 70% coverage then you need to use a solid bed trowel.....
A solid bed trowel is one that has notches that are deeper than they are wide...
thus when the tile is pressed into the bed it will spread out and create a solid fix....

hope this helps edd.....

pjc

if any of you find any trowel that i can put tiles straight on the floor with 100 % coverage let know please i use 13mm trowels put tile down pick tile up put more adhesive under tile put tile down, square half round oblong triangular whatever , every situation is different every tile is different every floor is different if only it was that easy:Pete