SL-300 Levelling Compound – Ideal for Electric Underfloor Heating (2–30 mm)

SL-300 is a high-performance self-levelling compound that combines exceptional strength with outstanding flow characteristics. It is specifically suited for levelling electric underfloor heating systems in both residential and commercial environments.

Whether you are renovating a home or completing a large-scale project in offices, retail spaces, workshops, or warehouses, SL-300 delivers a smooth, durable, and structurally strong subfloor.

Why SL-300 is Perfect for Electric Underfloor Heating

✔ Excellent heat conductivity around heating cables
✔ Applicable in layers from 2 to 30 mm
✔ High compressive strength (C40)
✔ Smooth self-levelling finish
✔ Suitable for heavily loaded floors
✔ Walkable after 3–4 hours

Thanks to its high strength classification and ability to be applied in thicker layers, SL-300 fully encapsulates electric heating mats and cables. This ensures optimal heat distribution and creates a stable base for tiles, PVC, laminate, or other floor finishes.

Technical Specifications

• Layer thickness: 2 – 30 mm

• Drying time (3 mm): approx. 24 hours

• Walkable: after 3 – 4 hours

• Strength class: C40

• Consumption: approx. 1.6 kg per m² per mm thickness

• Mixing ratio: 6 – 6.5 liters of water per 25 kg bag

The Right Primer for Perfect Adhesion

Proper surface preparation is essential when levelling over electric underfloor heating. The correct primer depends on the type of substrate.

ASTAR F – For Smooth and Non-Absorbent Substrates

ASTAR F is a powerful, fast-drying primer specifically developed for smooth and non-absorbent surfaces. Its advanced formulation ensures extremely strong adhesion, even on dense or glossy substrates.

Suitable for:

• Existing tile floors

• Smooth concrete

• Anhydrite floors

• Other non-porous surfaces

ASTAR F creates the ideal bonding layer for levelling compounds and tile adhesives, ensuring long-term performance and reliability.

ASTAR-V – For Absorbent Substrates

ASTAR-V is a high-quality, ready-to-use acrylic primer designed for absorbent substrates. It dries quickly and stabilizes the surface, significantly improving adhesion and durability of levelling compounds.

Suitable for:

• Sand-cement screeds

• Concrete floors

• Cement-based subfloors

• Other porous substrates

ASTAR-V prevents air bubbles and bonding issues when applying levelling compound over electric underfloor heating systems.

Complete System for a Strong and Level Floor

The combination of ASTAR primer + SL-300 levelling compound provides a perfectly smooth, strong, and durable base for any floor finish. Suitable for DIY homeowners as well as professional contractors.

If you would like assistance calculating material consumption or required thickness for your project, I’m happy to help.