Dry mineral
screed
Dry mineral screed system (natural stone) installed dry, with no drying time. Two ranges: LW86 (without heating) and Formplatt Lava Basalt (integrated underfloor heating). 100% recyclable, fire class A1, low installation height (45 mm).
What is dry mineral screed?
Dry mineral screed is an engineered floor system made of panels of crushed natural stone bonded dry, laid with interlocking joints and no drying time. The stone acts as both the loadbearing material and the thermal mass, while the tongue-and-groove geometry provides mechanical continuity between panels. The screed is laid floating on an underlay.
The system comes in two ranges. The first, without heating, provides either acoustic mass or, in a lighter version, thermal performance, depending on the variant. The second integrates heating pipes in direct contact with the floor finish, which gives very low thermal inertia and a fast temperature response.
The screed is intended for interior floors in new build and renovation, in housing, offices or public buildings, where the available depth is limited or where the floor must be brought into use quickly. It is laid on a loadbearing timber or concrete substrate.
It is manufactured in Germany by Lithotherm, from local stone. The panels remain separable at end of life and return to a mineral recycling route, with no hydraulic binder to separate out.
Installation & uses
Installation is dry, on a wood fibre underlay and a granular levelling bed that evens out the substrate and takes up local irregularities. The panels join by tongue and groove, with no mortar or adhesive.
On the heated version, the pipes slide directly into the preformed grooves in the panels, which ensures direct contact with the floor finish. Connection to the heating circuit follows a panel layout plan supplied by the producer.
The floor finish is then laid according to its own method: bonded tiles, natural stone, floating parquet, or parquet bonded to a dedicated timber profile. No drying time holds up the following trades.
At end of life, the panels can be lifted without breakage and reinstalled elsewhere, or crushed and returned to a mineral recycling route.
About the producer
Lithotherm is a German producer of dry mineral screeds, specialising for more than twenty years in natural stone panels laid dry. The company develops two complementary ranges, LW86 without heating and Formplatt with integrated low-temperature underfloor heating, as well as a related wall system.
Production follows a short supply chain, with local stone and a process that uses no hydraulic binder. The producer supports specifiers with a panel layout plan and technical support for installation.
Technical performance
Not covered by a harmonised standard. EN 13813 covers screed materials laid in situ, not prefabricated dry panels. The producer itself declares its F3/C12 classes “gemäß DIN EN 13813 in Analogie zu” DIN 18560-2 · an analogy is not coverage, and it rules out any DoP under this standard. No Declaration of Performance (Leistungserklärung) is published on the producer's website.
FAQ
What installation height should be allowed for?
45 mm total installation height, which places it among the lowest dry screeds. It is used on interior floors, as a screed.
How long before the floor can be brought into use?
None. The screed is laid dry, as tongue-and-groove panels, with no drying time: the floor can be walked on straight away. This is what makes it the choice for occupied renovations and tight programmes.
How does it perform in fire?
Classed A1, non-combustible: the panels are made of natural stone and mineral materials.
What happens to it at end of life?
Fully recyclable, as the panels are mineral and natural.
Alongside
Same layer, same use · three materials to compare.
Paper mill sludge and recycled paper, resin-free. Honext · Barcelona.
Reconditioned raised access floor (wood core + sheet steel). Mobius · Brussels.
Recycled Tetra Pak cartons, melted down (Recoma · Sweden).