How to prepare sub floor for tiling - To self-level or not?

[RKN00b]

Hello fellow DIY enthusiasts,

I'm embarking on a tiling project in my home and could use some advice from the experienced members here. I've already made some progress, but I want to make sure I'm on the right track before I proceed.

Here are the details:

Subfloor Preparation: I've removed all existing flooring, and I'm left with a concrete slab that's mostly smooth and flat. However, there are some variations in the surface. Most of the area has a +1-5mm tolerance, but there are a couple of corners with +15mm and +10mm variations. My main question is whether it's necessary to self-level the entire floor, or can I tile directly on it?

Area Size: This is a relatively large area, about 80 square meters, so I want to ensure I'm taking the right steps to ensure a successful tiling job.

Materials: I plan to use 600x600 porcelain tiles, along with a primer, adhesive, and the Clipit leveling system for consistent tile placement.

Before I start the tiling process, I want to make sure I've covered all the bases in terms of subfloor preparation. Are there any tips, tricks, or recommendations you can provide to help me avoid any potential issues down the road?

I've also attached some photos of the space to give you a better idea of what I'm working with. Any input you have would be greatly appreciated.

Thank you in advance for your help!

Looking forward to your expert advice.

Best regards,
RK

[EricL]

Hello @RKN00b 

You've done an excellent job in preparing your floor for tiling. Your instincts regarding floor levelling are spot on. I suggest using Dunlop 15kg Multi Purpose Floor Leveller to address the low-level spots on your floor. Because you are using very large tiles uneven flooring will be very evident and the tile adhesive can't compensate for such a high difference in flooring level.

My only other recommendation is to use Dunlop 4L Multipurpose Primer before you begin tiling.

Here is a link to a handy guide on how to use the floor leveller: Dunlop Floor Leveller

Please remember to wear personal protection such as gloves, goggles and a mask when working on your project.

If you have any other questions we can help with, please let us know.

Eric