Choose the wrong adhesive and tools when tiling and you could be heading for a DIY disaster – here's how to prevent one

Choosing the wrong adhesive and tools for a tiling job can have consequences. The biggest problem is that most issues aren't immediately obvious. Newly installed tiles can look good, but a poor bond from the wrong adhesive, poor application or shabby cuts will soon show itself – often in disastrous ways.

Tiling a floor and tiling a wall also involve subtle but important differences. So it's critical that you know the difference for a successful tiling project.

Here, I explain the adhesive you should use, the right trowel to apply it, and how to ensure clean cuts for a professional, long-lasting finish.

What can go wrong?

The problem with choosing the wrong materials and tools when tiling is that you rarely notice problems straight away. You can walk away thinking you've done a great job, but time will reveal issues eventually and some of them can be hard to rectify.

When a tile hasn't bonded properly for example, "problems can emerge later on with cracked or loose tiles, especially where a lot of movement is involved,” explains James Roberts, director at Sanctuary Bathrooms.

Stephen Russell, tiler at Ashley Cross Tiling explains what typically happens in this instance: "Tiles will come loose on floors and tiles will fall off the walls.” A DIY disaster any home renovator or self-builder would rather avoid.

But these aren't the only issues, James shares, noting how the right adhesive can also lead to additional problems with certain tiles. "With natural stone, staining is also another risk, and by that stage, when you've noticed the stain, putting it right could mean having to remove and refix the tiles, so a simple mistake in specification can turn into a substantial repair."

And, while the wrong adhesive may cause hidden problems that reveal themselves later on, using the wrong tile-cutting tool can ruin a tile instantly. You can use a score-and-snap tile cutter on ceramic and thinner porcelain tiles, but with materials like stone and thick tile, it can break unevenly, leave chips on the edges, or making it simply fall apart. Much the same as when using the wrong drill bit to drill into tiles.

It's clear that using the wrong materials and tools isn't as easily fixed as using the wrong colour when painting a wall, so with time, money and stress levels all at risk, here's how to make sure you avoid making mistakes.

Stephen Russell

Stephen is an independent tiler with other 30 years in the industry. He specialises in kitchen tiling, walls and floors and general tiling repairs.

James Roberts

James Roberts is a Director at Sanctuary Bathrooms, a family-run bathroom retailer based in Leeds. With a plumbing background and extensive retail experience, he regularly provides practical guidance on bathroom products, installation, and maintenance.

Think about the surface your sticking tiles onto

The surface you are sticking tile to will heavily influence how and what you use to apply your tiles.

Stephen Russell agrees: "The substrate certainly makes a difference; choose a recommended adhesive and make sure to read the label on the bag on how to mix and apply.”

James Roberts reinforces the point, telling us: “Absolutely. The adhesive can only perform as well as the background allows.”

If tiling onto plasterboard, “it must be dry, securely fixed, and able to carry the tile's weight," he continues. "Follow the adhesive manufacturer's priming instructions for plaster and boards.”

If tiling on tile, “existing tiles must be sound and clean, as well as suitably prepared for a non-absorbent surface,” advises James. If tiling onto concrete or screed, make sure it's dry and fully cured before tiling. Again, check the manufacturer's recommendation.

Finally, “timber floors deserve particular attention," warns James. "Current guidance calls for an appropriate middle layer over wood-based boards, such as tile backer board or an uncoupling system. A flexible adhesive alone can't make up for an unstable floor.”

Choosing tile adhesive

Many factors come into play when choosing a tile adhesive for a project. The first, and usually most important, is where you're applying the tiles: walls or floors.

Tile adhesive for walls

Generally, wall tiles are smaller than floor tiles, such as these Wickes Metro White Gloss Ceramic Wall Tiles. The other key difference is that you don't walk on wall tiles, unlike floor tiles. This means they experience less stress, wear and tear, so you don't need as strong an adhesive.

“On walls, a ready-mixed adhesive in a tub is the common option,” shares Stephen Russell. This means no mixing, so you can get straight to work.

“If you're heading to a hardware store, Mapei Ultimate Showerproof Adhesive (available from B&Q) is a decent choice," he suggests and I agree. It's one I've personally used on bathroom wall tiling projects and found it easy to use, and the tiles are still on the walls after five years.

James Roberts recommends an alternative ready-mixed option that can also cope with larger tiles. “BAL White Star Plus is suitable for ceramic tiles up to 300 × 300mm on approved backgrounds, including bathroom walls,” he shares.

“There are also powdered adhesives you have to mix available, which are typically cheaper," adds Stephen. “Mapei Fast Set Grey Tile Adhesive (available from B&Q) is a good option.”

However, you do need to be careful when working with larger tiles, explains James. "Once you move into larger tiles or most porcelain installations, a suitable cement-based powder adhesive is the better choice. Check its limits for tile size, background and bed thickness; convenience should never drive the specification," he warns.

Tile adhesive for floors

Stephen Russell offers one simple piece of advice when it comes to choosing floor tile adhesive, which is, “never use pre-mixed wall tile adhesive on floors.”

"For floors, use a powdered in-a-bag tile adhesive and always read the label,” he notes., as cement-based adhesives are the common option for floors.

“The setting time should suit the job," picks up James Roberts, telling us how standard-setting and rapid-setting options are both readily available.

Standard-setting tile adhesive, such as Mapei Grey Wall & Floor Tile Adhesive from B&Q, is a good option, especially for large rooms. It takes longer to set than rapid-set adhesive, giving you more working time.

However, if you need to walk on a floor within a few hours, you'll need a rapid-set adhesive such as Mapei Mapeker Rapid Set Grey Flexible Tile Adhesive (available from Wickes).

For floors with underfloor heating, you need an adhesive with a "deformable formulation that accommodates limited movement," explains James. “BAL Rapid-Flex One (available from Amazon) is an example of an adhesive that works well for ceramic and porcelain floor tiles, as long as you follow its substrate requirements.” Tile adhesive with the S1 or S2 flexibility rating is typically a good choice for underfloor heating.

Shop these tools for a better tile project

Choosing the right tools

1. Tools for cutting

Different tiles need different tools to cut correctly. Choose the wrong option, and you won’t get a clean cut, which can prove expensive. “Choose the cutter around the tiles you're actually using, rather than assuming one tool will handle everything,” is James Roberts' advise.

"Score and snap tile cutters will work on most wall tiles,” says Stephen Russell, with James adding that, “score-and-snap cutters are useful for straight cuts on ceramic and many porcelain tiles.”

My top tip? Don't forget to check the size of a score-and-snap tile cutter as you don't want to buy one and find out it doesn't accommodate your tiles. If you need more than a straight cut, you'll need an electric tile cutter like the Vitrex Torque Master Power Tile Cutter from Amazon.

“Floor tiles are much harder to cut,” picks up Stephen, noting how for porcelain you will typically need a specialised diamond-bladed wet cutter.”

“Natural stone generally needs an electric cutter too," adds James, "with an appropriate diamond blade."

Professional wet tile cutters are expensive, so you could instead invest in a more robust option, such as the Erbauer 750W Corded Tile Cutter from B&Q. Alternatively, you can hire one from a tool hire company such as HSS or SpeedyHire.

2. Sizing your trowel

The notches on a tiling trowel determine how much adhesive is applied. Choose the wrong size, and you might apply too little or too much, which can cause bonding issues.

“Always use a smaller notch trowel for walls and a large notched trowel for floors," says Stephen Russell. "A 6mm notch (like this Faithfull Soft-Grip Notched Tile Trowel from Amazon) is a useful starting point for small ceramic wall tiles. Medium-sized tiles installed with cement-based adhesive may need 8mm.”

Floor tiles need a bigger notch, adds James Roberts, noting how, “larger wall or floor tiles often need 10–12mm.”

For mosaic tiles, "a smaller notch is preferred to stop adhesive protruding from the joints," explains James. “The challenge with mosaics is getting good contact beneath every piece without filling the grout joints with adhesive, but, there's no universal size," he continues.

"BAL, for example, specifies a minimum 4mm notch (like this COMENSAL Notched Tiling Trowel from Amazon) for mosaics with Rapid-Flex One, while ARDEX WA specifies 3mm. Follow the mosaic and adhesive instructions, and check the contact beneath the pieces as you go along,” he suggests.

Choosing the right adhesive and tools is the practical part of a successful tiling project. However, you also need a bit of flair and inspiration, which you can find in our kitchen wall tile ideas and kitchen floor tile ideas to get the look you want. Add in the right tile pattern to make a room feel bigger to help complete your project.