What size notch trowel should I use ?

[sb24]

Was recommended some mapei p9 adesilex for my ceramic 360 x 275 (8mm) tiles going onto plaster in kitchen, by tile giant. It says adhesive thickness no greater than 5mm on the bag. As ive just finished doing my bathroom using tubbed adhesive and the walls were a bit off i was able to get away using a 10mm notch trowel and a 6mm trowel for different walls.

This will be my second project using cement based adhesive. My first being 100mmx100mm tiles being tiled on a fireplace. With this now being a step up, i thought i should ask and get a professional opinion. About how to go about putting this adhesive up as trowel sizes, adhesive thickness, bed thickness seem to confuse me. What trowel should i be using for adesilex p9. Thanks in advance

 

[Rookery]

Prime the plaster then use a 10mm notch.

 

[Qwerty]

As above ^^^

You may find that 8mm is fine depending on how flat your walls are.

 

[sb24]

Thanks for replying guys. So the 5mm adhesive thicknss it says on the bag once compressed and bedded with a 10mm notch will come to that 5mm thickness. Is that correct.

 

[Dumbo]

It will actually be less than 5mm as your trowel will be at approximately 45 degrees when applying adhesive which reduces the height to start with then it will then collapse when you bed the tile and end up with about 3mm bed depth .

 

[sb24]

I was just worried, as i wanted a bit of room for play in the walls where they might not be level to level things out as much as possible. So a 10mm notch seems the way to go . Thanks for the reassurances.

 

[sb24]

One final thing is it worth back buttering aswell as using a 10mm notch. Again not wanting to exceed the 5mm max thickness of adhesive.

 

[Bond]

One final thing is it worth back buttering aswell as using a 10mm notch. Again not wanting to exceed the 5mm max thickness of adhesive.

Probably a good idea to back butter tiles, you can use the flat side of the trowel.