Pro Tiler Tools

Tiling On An Uneven Floor: Weberfloor Flex

03/03/2025

When it comes to tiling, achieving a flat surface is crucial for both aesthetics and safety. While tiling on a level substrate is straightforward, uneven floors can present various challenges. In this article in collaboration with Weber, we explore how to tile an uneven floor, with the right substrate preparation. 

Common uneven tiling challenges you might encounter

When wanting to lay tiles, if your substrate is not properly prepared or even, you’ll likely encounter these problems:

Increased difficulty in laying tiles evenly

Using a notched trowel helps distribute tile adhesive uniformly on the substrate. When tiles are set with consistent pressure, they generally align well. However, if the substrate is uneven, maintaining this consistency becomes challenging, often leading to uneven tiles.

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Time-consuming substrate preparation

If your substrate has deep holes, it may require a thickness greater than standard thin bed adhesive allows. This can make the preparation process lengthy, especially if multiple holes need addressing. In such cases, opting for a thicker adhesive may be beneficial.

Read more: Which Tile Adhesive Is Best? A Guide To Classification Of Adhesives And Grouts

Variability in natural stone thickness

Uncalibrated natural stones, which are split rather than machine-cut, can vary in thickness. This inconsistency necessitates the use of a thick bed adhesive to accommodate the variations.

Combination of issues

When tiling over existing ceramic tiles, you might face a mix of the above challenges. Some tiles may need removal due to poor adhesion, while others might not be level.

Read more: The Best Adhesives For Tiling Over Tiles


Tiling On An Uneven Floor: Selecting the right materials

The approach to tiling an uneven floor depends on the substrate's condition. Begin by filling deep holes with a suitable repair mortar. Using a levelling compound can create a smooth surface, but for uncalibrated stone, a thick bed tile adhesive is essential.

1. Repair mortar for larger holes

For holes exceeding 20mm in depth, a repair mortar like Ardex A46, Ultra Floor Patch It, or Webercem Pyrapatch is ideal. Ensure to remove any loose material and cut edges squarely. Fill these holes appropriately and allow for full curing.

2. Levelling compound application

A self-leveling compound, such as weberfloor flex is ideal for smoothing out irregularities and creating a flat surface for tiling. Ensure the substrate is clean, dry, and firmly adhered before applying. Primer is always worthwhile, so consider priming the surface with something like weber PR360 prior to pouring the levelling compound, taking care to maintain movement joints through the screed and tiler layer.

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3. Use a tile levelling system

A tile levelling system is a simple and efficient tool that helps keep your tiles in place as they set, enhancing the overall appearance of your tile installation.  It can also minimise the height differences between adjacent tiles, which is especially important for large format tiles that may be more prone to warping. There are many solutions available from tile levelling clips, tile wedges, and tile pegs and spacers to spin levelling systems.

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4. Choosing the right tile adhesive

For uncalibrated natural stone, a thick bed adhesive like weberset thick bed is required to manage the natural irregularities. Go-to thick bed adhesives for up to 25mm thickness are Ardex X325 PTB and BAL XL Floor One, or for up to 20mm thickness Ultra ProEco Gel is a good choice. 

If tiling with uniform ceramic or porcelain tiles, consider using weberset SPF or weberset SPF rapid.

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5. Finishing touches with tile grout and silicone

Complete your tiling project by filling joints with weberjoint premium grout, available in various colours, and sealing edges with weberjoint premium silicone sealant, which can be colour-matched to your grout selection.

If you have any questions or need further assistance regarding tiling uneven floors, our team is here to help! Whether you require technical support, guidance on product selection, or any other information, don’t hesitate to contact our team of experts should you have any questions, via email at [email protected] or give us a call at 01604 859800.