How much anhydrite screed do I need?

Multiply your floor area by the screed depth. For 50m² at 40mm depth: 50 × 0.04 = 2.0m³ of screed. Anhydrite screed weighs approximately 2.1 tonnes per m³.

How long does anhydrite screed take to dry?

Allow approximately 1 day per mm of depth for the first 40mm, then 2 days per mm above 40mm. A 40mm screed takes about 40 days to dry. Mechanical drying can reduce this significantly.

What depth of anhydrite screed over underfloor heating?

Minimum 25mm above the top of UFH pipes (typically 35–40mm total depth for 16mm pipes). Deeper screed stores more heat but takes longer to warm up. 40mm is the most common domestic specification.

How is anhydrite screed delivered?

Anhydrite screed is delivered by mixer truck and pumped through a hose. Typical pump rates are 20–40 m³ per hour. A 50m² room at 40mm can be poured in about 4 minutes.

Does anhydrite screed need priming before tiling?

Yes. Anhydrite screed must be primed before applying tile adhesive. The laitance layer (surface film) must also be sanded off at 7–10 days. Use a specialist anhydrite primer at 0.15 L/m².

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Anhydrite Screed Calculator — Volume, Pump Time & Drying

Calculate anhydrite flow screed volume from area and depth, pump delivery rate and drying time allowances.

Floor Area

Total area to screed

Screed Depth

40mm standard over UFH

Price Per m\u00b2 (optional)

How We Calculate This

This calculator determines anhydrite screed volume and delivery logistics from your floor area and depth specification.

The formula

Volume (m\u00b3) = Floor area (m\u00b2) × Depth (m)

Weight (tonnes) = Volume × 2.1 t/m\u00b3

Drying (days) \u2248 Depth (mm) × 1 day/mm (first 40mm)

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Verify with your supplier.