Floor Tile Adhesives

Standard set Standard adhesives take longer to cure — you'll typically need to wait 24 hours before grouting a floor. The upside is a much longer pot life (the time you have to use the mixed adhesive before it sets), which makes them easier to work with on larger jobs. If you're tiling a whole room, standard set gives you time to work at a comfortable pace.

Rapid set Rapid adhesives cure much faster — most allow you to grout and walk on the floor after just 3–4 hours. They're ideal when the room needs to be back in use quickly, such as a hallway, kitchen, or bathroom. The trade-off is a shorter pot life, usually 30–60 minutes, so you need to mix smaller batches and work efficiently.

For most DIY jobs without a time pressure, standard set is the easier option. If you need the room back in use the same day, go rapid set.

For most domestic floor tiling jobs — bathrooms, kitchens, hallways — a standard flexible S1 adhesive is the right choice, and nearly all the products in our floor range are S1 classified.

S1 flexibility means the adhesive can absorb a small amount of movement in the floor without cracking the bond. This matters more than it sounds — floors naturally expand and contract slightly with changes in temperature and humidity, and a flexible adhesive accommodates this rather than fighting it.

You particularly need S1 flexibility if you're tiling over underfloor heating, timber floors (via backer board), or any substrate that may move slightly. If in doubt, S1 is always the safer choice and costs no more than a non-flexible equivalent.

Yes — all the adhesives in this range are suitable for both floors and walls. So if you're tiling a bathroom with the same tiles on the floor and halfway up the walls, you can use one product for the whole job.

The only thing to be aware of is that wall tiles need a non-slip adhesive so tiles don't slide down before the adhesive sets. All the products here have non-slip properties built in, so this isn't something you need to worry about.

Ready-mixed adhesives from our wall tile adhesive range are wall-only and not suitable for floors — but everything in this floor range works on both.

For tiles larger than 600×600mm you'll need one of the S1 flexible cement-based adhesives in this range — the two Mapei products (Adesilex P9 and Mapeker Rapid Set Flex) are rated up to 600×600mm only, so rule those out for larger formats.

The key things that matter with large format tiles are a very flat substrate (any unevenness is magnified with bigger tiles), full back coverage (always butter the back of the tile as well as the floor), and enough open time to position and adjust heavy slabs accurately. For this reason a standard set adhesive with a longer open time is often easier to work with for large format tiling than a rapid set.

Also make sure your notched trowel is the right size — large format tiles need a larger notch (typically 10–12mm) to create sufficient bed depth and coverage.

Yes — all the products in this range are compatible with underfloor heating systems. You do need to follow a few important steps to avoid problems.

Before tiling: the heating system must be fully commissioned and tested before you start. Turn it down to a maximum of 15°C during installation — higher temperatures will dry the adhesive too fast and could cause it to fail.

After tiling: keep the system at 15°C or below for at least 7 days after tiling. Then raise the temperature gradually — no more than 5°C per day — until it reaches normal operating temperature. Never jump straight to full heat.

A flexible S1 adhesive is essential over underfloor heating, as the floor expands and contracts with temperature changes and a rigid adhesive can crack the bond over time.

It depends on the type of stone. Most natural stone — granite, slate, quarry tile, travertine, sandstone — can be fixed with any of the adhesives in this range.

The exception is moisture-sensitive stone such as limestone, some marbles, and pale or translucent stones. These can absorb water from a standard cement-based adhesive during fixing, which causes staining or darkening that won't go away. For these stones you should use a white adhesive, and specifically one that is rated for moisture-sensitive natural stone.

From our floor range, Kerakoll H40 Gel and BAL Flex One are both suitable for moisture-sensitive natural stone. If you're not sure whether your stone is moisture-sensitive, do a simple test — wet a small area with clean water and see if it darkens. If it does, use one of those two products.

Always use the white variant of whichever adhesive you choose for pale or light-coloured stone, as grey adhesive can show through thin or translucent stone.

It varies by product, but as a general guide:

Rapid set adhesives Rapid — light foot traffic is usually possible after 3–4 hours at 20°C. However, you should still wait until the adhesive has fully cured before putting the floor under heavy use — typically 24–48 hours for normal traffic.

Standard set adhesives Standard — allow at least 24 hours before any foot traffic. For heavy use such as furniture or full household traffic, wait 3–5 days.

These times assume normal indoor temperatures around 20°C. In colder conditions the adhesive takes longer to set — in a cold garage or conservatory in winter it could be significantly longer. In very warm conditions it may set faster but can also dry too quickly, so avoid working in direct sunlight or strong heat.

You also need to wait until after grouting before walking on the floor, so factor in the grouting time too.

It depends on what your floor is made of. Most concrete and cement screed floors don't need priming — just make sure they're clean, dry, and dust-free before you start.

You will need to prime in these situations:

Anhydrite or calcium sulphate screeds (often used with underfloor heating) — these must be sanded, dried to the correct moisture level, and primed with a compatible primer before tiling. Each adhesive brand has its own recommended primer — check the product data sheet.

Very porous or dusty surfaces — a diluted primer coat will seal the surface and improve adhesion.

Plywood or timber floors — need priming before the backer board goes down.

If you're not sure, check the technical data sheet for the specific adhesive you're using — it will list which surfaces need priming and which primer to use.

Yes, in most cases — tiling over existing tiles avoids the time and mess of removing them. But there are a few things to check first.

The existing tiles must be firmly bonded to the floor — tap each tile and listen for a hollow sound, which indicates it has de-bonded underneath. Any loose or hollow tiles must be removed and the area made good before you tile over.

The existing surface must be clean and grease-free — any polish, wax, or grease will prevent the new adhesive from bonding. Clean thoroughly before starting.

Bear in mind that tiling over existing tiles will raise the floor level by the thickness of the new tiles plus the adhesive bed — typically 8–12mm. Check this won't cause problems with door clearances or transitions to adjacent flooring.

Most of the adhesives in this range are suitable for tile-on-tile fixing — check the individual product page for confirmation.

Coverage varies depending on the adhesive, the size of your notched trowel, and how uneven your floor is — so there's no single answer that works for every job.

The easiest way to work it out is to use the adhesive calculator on each product page — just enter your floor area and it will tell you how many bags you need. You'll find the calculator on the individual product listing.

As a rough guide, a 20kg bag of floor adhesive will cover somewhere between 3 and 6 square metres depending on the product and trowel size. It's always worth buying a little more than you think you need — running out mid-job and having to wait for more to arrive is frustrating, and most unopened bags can be returned.

The technical performance is identical — grey and white versions of the same adhesive will bond just as strongly and last just as long. The difference is purely visual.

Grey adhesive is the standard choice for most floor tiling jobs and is usually slightly less expensive. It works perfectly well under opaque tiles where the adhesive colour won't be visible.

White adhesive is worth choosing when fixing pale or light-coloured tiles, natural stone, glass mosaics, or any tile where grey might show through the material or the grout joints. It's also the right choice for moisture-sensitive natural stone, as white adhesives typically contain less water.

If your tiles are dark or fully opaque, grey is fine. If you're not sure, white is always the safer option.

Yes — all the products in this range are suitable for bathroom floors. For wet rooms and shower areas, all are suitable too, but there's one important additional step: the floor must be waterproofed before tiling.

Tile adhesive alone is not a waterproof barrier — water will eventually work its way through grout joints and reach the floor beneath. In a wet room or shower area, this can cause serious damage over time. A waterproofing membrane (also called tanking) applied before tiling prevents this.

Most adhesive brands have a compatible waterproofing product — for example BAL Tank-It, Mapei Mapegum WPS, or ARDEX WPC. Apply the membrane, allow it to cure, and then tile over it as normal.

For swimming pools, check the individual product page — most products in this range are suitable, but a few are not, and some require specific additional products such as a specialist admix for the adhesive.