Round or Square notched trowel?

[Muppet Man]

Doing an 18 SQ Meter dining room floor next week with 45cm square ceramic tiles onto new concrete floor. Rapid set powder adhesive.

I have an 8MM square notch trowel and a 10 MM Round notch trowel.

Never used the round one before.

Any suggestions one which one is best to use for my scenario.

Thanks,
Muppet Man.

 

[skiptonstone]

Hi, Definitely use the 10mm Round notched trowel, and just a quick one, when you say "new" concrete floor it has been laid a good few weeks hasn't it? If not you will have problems....

 

[CJ CERAMICS]

use the round trowel as this will raise the adhesive higher from the floor giving a greater coverage and allow you to compress your tiles to bed easier and also allows more flexability in levelling if the floor is not quite true. but like skipton says i would make sure that the concrete floor has cured fully.

 

[Muppet Man]

Thanks guys, appreciate the advice. I will use the round notch trowel then.

I too am worried about the concrete floor. As far as I can tell its about 2 to 3 weeks old. What problems am I likely to encounter... shinkage or expansion? Leading to cracked grout I suppose....? Would it ever be bad enough to actually crack a tile (ceramic)...

Thanks guys, great forum. Great advice.
Muppet Man.

 

[skiptonstone]

Im my experience working for the tile sheds word on the ground is that you should leave a new concrete floor for Six Weeks before tiling on.

 

[DHTiling]

You can use an adhesive that is suitable for tiling to green screeds or use a product like Ditra that allows the floor to dry out via the vapour equalisation cavities of the mat.

 

[doug boardley]

I use the round notch "solid bed" trowel mate. Avoid the voids!

 

[grumpygrouter]

With Dave on this one....would def consider laying Ditra or Durabase if you can't wait long enough for the concrete to dry properly.

 

[CJ CERAMICS]

prefer to lay ditra just for peace of mind i like to home knowing ive done everyything possible to ensure best results and not to just make the most money............probably why im going bust...lol