Kerakoll Keracem fast-drying screed binder

Large area, your own sand and mixer — but does the cement screed take weeks to dry? The parquet installer cannot start until then. Keracem replaces the cement in the mix, with 0–8 mm sand. On a 5 cm layer, moisture is ≤ 2% after 5 days. Ceramic tiles can be laid after 24 hours, parquet after 5 days. This is Kerakoll Keracem.

• Large areas, on-site mixing: binder for 0–8 mm sand — the sand can be sourced locally; only the binder needs to be transported
• The parquet installer won't have to wait: moisture ≤ 2% after 5 days on a 5 cm layer — parquet after ≈ 5 days, ceramic tiles after ≈ 24 hours
• Different load, different dosage: 200 kg/m³ for ceramic tiles (≥ 32 N/mm²), at least 250 kg/m³ for parquet (≥ 45 N/mm²) — the mix is tailored to the floor covering
• Weak surface beneath the floor covering: higher mechanical performance than Portland cement, with a reduced water/cement ratio — binder compressive strength ≥ 55 N/mm²
• Cracking, shrinkage: shrinkage-compensated screed with high volume stability — outstanding, long-lasting dimensional stability
• Manual and machine application: pot life ≥ 3 hours — sufficient time for spreading and compaction
• Underfloor heating, terraces, frost: for interior and exterior use, including high temperature fluctuations and underfloor heating — one binder for the whole house
• Any bonded floor covering: porcelain tiles in all sizes, stone, marble, parquet, PVC, rubber, linoleum, carpet — one substrate, many types of flooring
• Living areas, children's rooms: EC 1 plus and A+ indoor emissions classification — very low VOC emissions

What is it suitable for?

Screed: Bonded screed (bonded directly to concrete, ≥ 20 mm) and floating screed (laid on film or insulation, ≥ 40 mm), mixed with 0–8 mm sand; underfloor heating.

Floor coverings (with adhesive): Porcelain tiles and ceramic tiles in all sizes, clinker, terracotta, glass and ceramic mosaics; natural stone, engineered stone, marble; parquet; rubber, PVC, linoleum, carpet.

Substrates: Precast or cast-in-place concrete slabs and bases; lightweight cement screed; thermal and acoustic insulation panels.

Areas: Indoors and outdoors — homes, shops, industrial spaces; also surfaces exposed to frost and significant temperature fluctuations.

Not suitable for:

• On its own, without sand — this is a binder, not a ready-mixed screed
• On deformable substrates without bending calculations
• Without expansion joints
• On concrete that has not fully cured, as a bonded screed
• For substrates affected by rising damp

The Kerakoll screed range

The screeds belong to the self-levelling compounds and screeds category. All five are mineral, fast-drying screeds for bonded coverings. The differences are strength, tiling time, and application location.

*Keracem: 28-day compressive strength at dosages of 200 and 250 kg/m³, respectively. All times at +20 °C and 65% relative humidity.

What they all have in common: mineral, fast-drying screed for bonded coverings; also suitable for underfloor heating; EC 1 plus and A+ indoor emissions; moisture measurement only using the CM method.

Which screed do you need?

• Home renovation, ceramic tiles or parquet, normal load: Massetto Premix — easy-to-apply ready-mixed screed for normal loads
• Large area, own sand and mixer: Keracem — this product
• Underfloor heating, any bonded covering, indoors and outdoors: Keracem Pronto — good thermal conductivity, CT-C30-F6
• Cementoresina microcement, parquet after 3 days, heavy traffic: Keracem Prontoplus — fibre-reinforced, CT-C60-F7
• Tight schedule, indoors: Rekord Pronto — walkable after 3 hours, ceramic tiles after 6 hours

Layer build-up for Keracem screed:

Frequently asked questions

How long does the screed take to dry?
The moisture content of a 5 cm Keracem screed is ≤ 3% after 24 hours and ≤ 2% after 5 days. Ceramic tiles can be laid after ≈ 24 hours and parquet after ≈ 5 days. The times apply at +20 °C and 65% humidity.

In what ratio should I mix it with sand?
For ceramic tiles, 200 kg/m³: 1 bag, ≈ 200 kg of 0–8 mm sand, max. 16 l of water. For parquet, at least 250 kg/m³: 1 bag, ≈ 160 kg of sand, max. 14 l of water. The amount of water is for dry sand - less is needed for damp sand.

What kind of sand is needed for the screed?
0–8 mm graded aggregate, free of soil and dust, for thicknesses of 25–80 mm. For other thicknesses, the largest grain size should be ≈ 1/3 of the layer thickness.

How much binder is needed per 1 m²?
≈ 2–2.5 kg per centimetre. For a 5 cm screed, one 25 kg bag is enough for ≈ 2–2.5 m².

Is it suitable for underfloor heating?
Yes. The heating can be switched on at least 5 days after laying: for 3 days at a flow temperature of +20–25 °C, then for at least 4 days at the planned maximum. After that, return to room temperature and the covering can be laid (EN 1264-4).

How is it better than ordinary cement?
It requires less water and has higher mechanical performance than Portland cement. The screed has compensated shrinkage and dries quickly, so it can be covered sooner.

Keracem or ready-mixed screed?
For large areas, use Keracem with your own sand and mixer; the dosage can be adjusted to the load. Keracem Pronto is a ready-mixed product. It only requires water, reducing the risk of mixing errors.

How should I measure the screed's moisture before laying parquet?
Only with a calcium carbide (CM) meter. An electrical moisture meter gives fluctuating, unreliable readings with this screed.

When should I not use it?
Not without sand, on a deformable substrate or without expansion joints. Do not add water, binder or additives while it is setting. Too much water and unsuitable sand weaken the screed and slow its drying.

Can I apply it myself?
Product intended for professionals. The exact mixing ratio, compaction and expansion joints determine the floor's strength - it is best to entrust this to a professional. We also undertake installation.