Floors · 7 min read
Microcement over underfloor heating — the technical deep-dive
How microcement performs over wet and electric UFH, ramp-up profiles, what your heating engineer needs to know, and why it outperforms tile thermally.
By Jonathan Heywood · 6 July 2025
If you have UFH and you're choosing a floor finish, microcement is probably the best technical answer available. Here's why, and what your heating engineer needs to know.
Thermal performance
Heat transfer through a floor follows the inverse of thermal mass. Tile at 10–12 mm plus 6 mm of adhesive presents 16–18 mm of mass above the screed. Microcement at 2–3 mm directly bonded to the screed presents 2–3 mm. The UFH responds faster, achieves setpoint sooner, and cycles less.
Commissioning protocol
Before microcement is applied, the heating engineer must complete a full commissioning cycle: 1 °C per day from ambient to 25 °C, hold for 72 hours, return at 1 °C per day. This drives residual moisture from the screed and verifies the system. We will not install over an uncommissioned screed.
Movement joints
Screeds have control joints. These reflect through microcement unless we detail them as expansion joints in the finish. We design these into the layout at the survey stage — typically running along grain lines of the room.
Electric UFH
Works equally well. Slightly less commissioning fuss. Best paired with a tile-backer board or self-levelling compound over the mat before microcement.
The result
A floor that's warm underfoot, fast to respond, cheaper to run than tile, and seamless across the room. See our overview article or book a free site visit.