Tile levelling system for 300mm floor tiles

[Rabbit Chef]

I need to lay some tiles on a bathroom floor area of about 2m by 2.7m.
The tiles are 300mm square porcelain. The floor is 18mm plywood, marmox, heating mat and SLC.

Despite my best efforts, the floor is sloping slightly. It's about 7mm out over the 2m width.

Can I use a floor levelling system when the slopes as above? Will it take the slope out of the floor.

Which system is recommended for someone who hasn't used one before? I've been looking at the Gemini Easy Level system.
Thanks

 

[J Sid]

no

get another bag of slc and get level before you start

 

[WetSaw]

I think you've completely misunderstood what levelling systems do, that is get the tiles level with each other. They shouldn't be needed with small tiles and would probably make the job harder. If the floor is flat not level and you are not bothered about it sloping just tile it. Otherwise as above, prime again and another layer of SLC to get it level.

 

[Rabbit Chef]

Thanks for replies.
I realise that the levelling system is to avoid lippage between the tiles and not designed to fix the slope.
I was more wondering if such a system can still prevent lippage when used on a floor sloping as described.
The last time I tiled a floor, the tiles had a slight rounded edge so any slight lippage wasn't really noticeable (to me). The tiles this time have a sharp edge. I wanted to use the levelling system this time because I think any lippage will be much more visible.
I do have some Mapei renovation screed but believe I can't feather edge it?

 

[J Sid]

give it a couple of mm over the high area to 9mm over the low area