How Thick?

[Stoobydale]

I am going to lay some Hardibacker board tomorrow, but I have a question. How thick will the bed of adhesive be if I use a 6mm square notched trowel and how thick if I use an 8mm square notch? The instructions recommend a 6mm but I only have an 8mm, should I just use it or buy another? That was 2 questions.
Cheers,
Stu.

 

[Ian]

There won't be much difference in thickness, probably a mm or so. I'd still advise to use a 6mm trowel so you ensure a solid bed of adhesive under the boards.

 

[Stoobydale]

Thanks for the reply Bri, looks like i'll have to pick up another trowel tomorrow.

 

[AliGage]

It is 1mm difference isn't it?

I always thought with square notch trowels the finished bed size is half of the trowel tooth size.

10mm - 5mm
8mm - 4mm
6mm - 3mm
3mm - 1.5mm

However, this is more a presumption, don't think i've ever been told this. So i could be wrong.