Floor tiles - notched OR flat bed ?

[zappastix]

Hi

I have brought Wickes ceramic tiles that are recommended for both walls and floors.

These tiles are natural stone 'effect' and are 10mm thick x 300mm x 400mm.

They are very light weight tiles. The back of the tiles are white.

The instructions say to use notched trowel BUT they do not give separate
instructions for laying both Floor tiles and Wall tiles.

I would like confirmation that it is OK to used notched trowel for floor and NOT use
a FLAT bed of adhesive (I'll be using BAL slow setting stuff).

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MY QUESTION

Does a notched trowel finish provide enough strength to walk on?

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I have never tiled a floor before so I'm a bit in the dark.

I've got a 6mm square trowel for the wall and a 20mm round trowel for the floors.

Thanks in advance.

 

[Richard C]

Floor tiles must use & a thick solid adhesive bed (100% fully supported) or you risk them cracking under any load; for tiles up to 300mm x 300mm use a trowel with 20mm round notches, 10mm deep, at 28mm centres. For tiles larger than that, use a large format trowel which has a slightly deeper notch - 20mm round notch, 13mm deep, at 28mm centres. Wall tiles don’t generally need a solid adhesive bed but on anything over 200mm square, I use a solid bed trowel with a 10mm deep notch.

You don’t say where your tiling & those are really large/heavy tiles, I hope you’ve done your prep correctly. Plaster in good condition has a maximum weight limit of 20kg/sqm & most likely wont support tiles that size; raw plasterboard is slightly higher at 32kg/sqmm but be careful where you use it (not in wet areas). Anything heavier needs either render (not advised if your short on time) or tile backer board & the adhesive will account for 3/4kg/sqm which you must take into account. Suspended floors need special attention if you want it to last & you MUST use powder cement based addy of the correct type for tiles that size & prime any plaster or plastrboard but what exactly do you mean by "slow setting stuff"?

If you feel you need further assistance, post more detail & I can give further, detail advice.

 

[zappastix]

Thanks Richard C.

The tiles are extremely light.

Wickes reckon that the stone/cracked marble effect is obtained from different photographs/images
so each tile is different (at what point they match I'm not sure).

I am using BAL Single Part Flexible (not rapid set) after I spoke with their technical department
because the floor is concrete BUT laid over with vinyl tiles which are very old and contain asbestos.

They pointed me to BAL SPF, and said if the floor is clean I can go straight on to floor tiles without
any further preparation.

Could you please confirm this point; - When you say;

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Floor tiles must use & a thick solid adhesive bed (100% fully supported) or you risk them cracking under any load;
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Does it work like this: I use the correct notched trowel, and when slight pressure is applied to the floor tiles the
"notches of adhesive" push/join together to form a 'solid bed'

The walls did have tiles on before. The plaster appears to be sand and cement (is that right - seems very tough).


Thanks.

 

[Richard C]

I am using BAL Single Part Flexible (not rapid set) after I spoke with their technical department because the floor is concrete BUT laid over with vinyl tiles which are very old and contain asbestos. They pointed me to BAL SPF, and said if the floor is clean I can go straight on to floor tiles without any further preparation.

Despite what BAL say, I personally wouldn’t risk it & would remove the tiles; unless you can be sure they are very securely stuck to the floor you could risk failure.

Does it work like this: I use the correct notched trowel, and when slight pressure is applied to the floor tiles the "notches of adhesive" push/join together to form a 'solid bed'

Yes; the type of notch trowel you use dictates the adhesive bed. Push down firmly & use a very slight side to side twisting motion the bed & level the tile; same technique for wall tiles. TBH, you will be OK with the smaller 10mm deep notch trowel which is all I use unless the tiles are like paving slabs!

The walls did have tiles on before. The plaster appears to be sand and cement (is that right - seems very tough).

Sounds like the tiles may have been laid directly onto a sand/cement render but you need to be sure because if it's a Gypsum plaster you must prime to avoid possible reaction with cement addy. If it’s in good condition, it will take up to 45kg/sqm so you should be OK. To fill any holes or level hollows, use the powder addy; with Rapidset you can tile over the same day but if you use SPF, I would leave it for at least 12 hours before tiling over.