Question about laying tiles over UFH matting

[Element]

If I have already laid the matting, either in SLC or rapid flexy adhesive, allowed it time to set / dry and I am then going to spread & lay some more flexy on top for the tiles... Is it better to use a notched trowel or not. I'm thinking that if I use a notched trowel to even the spread of adhesive, when putting a tile on top, it will inevitably have air trapped in places beneath the tile. When the UFH is switched on (eventually) these air pockets might expand greater than the surrounding adhesive and potentially lift the tile or crack the grout? I have laid a few floors with UFH and I have used a notched trowel, but this question has always been in the back of my mind, I am shortly going to do a large job with UFH and thought I'd raise this point and get it settled once and for all (for peace of mind)... What do you folks think?

 

[Kevboy]

I've always used a notched trowel and haven't had a problem yet

 

[One Day]

The point of a notched trowel is to enable a tiler to get a consistent bed depth.
Compressing and wiggling a tile into the notches (***should***) get you a solid bed and expel any air. Especially if tiles or stone are back buttered.

I'd suggest (in a friendly way) that if you think air pockets are "inevitable" when using a notched trowel then you have quite some learning to do....

 

[Element]

Ahh well, I have taken up a fair few tiles and regularly see these air pockets (thin they are, granted - but they are there none the less). I realize the notches are there to control the bed thickness but have always wondered about this issue - no need to worry about it then!