Four adhesives, one system — here is the Kerakoll H40 tile adhesive line

The hollow large tile. The detaching facade tile. The loosened pool grout. Three different problems, one common cause: the adhesive wasn’t right for the task. The four members of the H40 gel adhesive line respond to four types of loads — let’s see which one is yours.

Most tiling failures don’t appear during installation. They show up weeks or months later.

Large tiles hollow because the adhesive didn’t fully wet the back — voids remained underneath. Facade tiles detach because the rigid bond couldn’t handle thermal movement. Pool grout loosens because chlorinated water gradually dissolves the adhesive.

The good news: these loads are known in advance. If the adhesive is made for the specific task, failure doesn’t start. Kerakoll built the H40 line on this principle — not promising a universal product for everything, but four adhesives, each for a specific situation. All four are in stock and available to order.

What is gel adhesive?

Traditional tile adhesive is either thixotropic (thick, non-slipping on walls) or fluid (spreads, provides full bedding on floors) — combining both is difficult.

Kerakoll’s gel formula is both thixotropic and fluid. On walls, the tile does not slip; on floors, the mix spreads and fills voids under the tile. That’s why the same bag works for walls and floors: mixed with less water for walls, more for floors.

Complete back wetting is key. Where there are no voids under the tile, there is no hollow sound, and the load is evenly distributed. This keeps the tiling intact for years.

The GT method in one sentence

Modern tiling faces more demands than the standard measures: large format tiles, underfloor heating, and facades apply torsional and bending forces to the adhesive. Kerakoll developed its own test — the GT method — which measures exactly this real load and classifies it into three levels. The more problematic the substrate, the higher the GT level required. The level is indicated next to each product in the table.

Which H40 adhesive is yours?

Tested with all four GT methods, suitable for porcelain tiles, ceramics, and natural stone. All are suitable for indoor and outdoor use, underfloor heating, and terraces. The difference lies in the task.

Below is a bit more detail on all four — after that, you only need to read about your own.

H40 Gel — the general choice

Smooth, stable substrate, general tiling, underfloor heating, large tile. H40 Gel is flexible, with 60 minutes open time — you have time for double application and adjusting large tiles. Walkable in 24 hours.

This is the default adhesive for most home renovation tasks. Porcelain tile from 30×30 cm to large slabs up to 160×320 cm, bathroom, kitchen, terrace. Successor to the former Biogel No Limits — same category, updated formula.

→ Kerakoll H40 Gel — 25 kg bag, grey or white

H40 Advanced — when time is tight

Want to grout the next day but the standard adhesive hasn’t set yet? H40 Advanced is walkable and groutable in 3 hours — you move forward the same day, the project doesn’t pause for a day.

Designed for two situations. One is tight deadlines: handing over a home, opening a store. The other is cold: it sets even at +5 °C, so work doesn’t stop in autumn, winter, or unheated spaces. Bonus: better for water-sensitive natural stone because less moisture reaches under the stone thanks to fast setting — no staining or bulging.

→ Kerakoll H40 Advanced — 25 kg bag, grey or white

H40 Tech — for moving substrates, facades

If the substrate moves or heat causes strong expansion, rigid adhesive cracks and the tile detaches. H40 Tech is the ultra-flexible member of the line, with the highest flexibility rating.

This adhesive is needed when the task goes beyond a simple cement substrate: facade, cracked substrate, wood or metal carrier, large tile reinforced on the back with fabric or resin. Where Gel is no longer enough, Tech provides the extra. Successor to the former Biogel Revolution.

→ Kerakoll H40 Tech — 20 kg bag, grey

H40 Extreme — water, chemicals, metal

Where water, chemicals, and thermal movement combine, cement bonding is insufficient. In pools, chlorinated water eventually dissolves it. On metal, aluminum, cement adhesive barely sticks.

H40 Extreme is the only hybrid, two-component reactive adhesive in the line. The setting is not triggered by water but by the reaction of components A and B — so it holds underwater, on metal, and under industrial chemical exposure. The 10 kg monopack pre-measures the two parts, so the ratio cannot be messed up.

This is the most expensive of the four, and not needed for everything. But repairing a delaminated pool tile or industrial floor often costs many times more than the adhesive.

→ Kerakoll H40 Extreme — 10 kg monopack, white

One system, not four separate products

H40 is not four adhesives randomly placed side by side. One line, with a common gel formula, common GT testing. It fits seamlessly with the rest of the Kerakoll system:

• Wet areas, pools: H40 and Kerakoll waterproofing together form a monolithic, waterproof layer — in bathrooms, showers, pools.
• Grout: the Color Fill decorative grouts complete the tiling.

Kerakoll is an Italian manufacturer from Sassuolo — developing building materials since 1968. The H40 name has been a tiling reference for over 50 years. The H40 Gel, Advanced, and Tech contain fillers recovered from mining waste and have EC1 Plus certification — very low emissions, safe indoors for both the tiler and those living there afterwards.

Not sure which one you need?

Describe the task — what kind of tile, what substrate, indoor or outdoor, is there underfloor heating or water — and we'll tell you which H40 adhesive is right for you. We also offer tiling services; contact us for this.

Old walls absorbing moisture, mold, wet basement? That's a different task — and we have a system for that too. We also demonstrate this in our showroom: feel free to contact us.

The full range can be found in the tile adhesives category.