Inputs
Results
Enter your floor size then click Calculate.
UKUK Building Regulations
References & Sources
Standards Cited
- BS 8204-1 — Screeds, bases and in situ floorings — Concrete bases and cement sand levelling screeds — Code of practice
Defines screed types, thickness requirements, and drying time guidance used in the calculator - BS EN 13813 — Screed material and floor screeds — Screed material — Properties and requirements
Specification for screed materials including density and performance classification
Formulas Used
- Screed volume:
volumeM3 = length x width x (thickness / 1000)
Source: Basic geometry - Weight and bags:
bagsRequired = ceil((volumeM3 x (1 + wastage/100) x density) / 25)
Source: BS 8204-1 — Densities: traditional 2200, liquid 2100, fast-drying 2200, fibre-reinforced 2200 kg/m3 - Ready-mix tonnes:
readyMixTonnes = wetVolumeM3 x 2.2
Source: BS EN 13813 — Average screed density of 2200 kg/m3 for ready-mix estimation - Bag coverage:
coverage = bags x 0.4 / thicknessMm
Source: BS 8204-1 — ~0.4 m2 per mm thickness per 25kg bag
Key Assumptions
- Screed densities: traditional 2200 kg/m3, liquid 2100 kg/m3, fast-drying 2200 kg/m3, fibre-reinforced 2200 kg/m3 — BS EN 13813
- Drying time: traditional 1 day per mm, liquid 24-48 hours walkable, fast-drying 3-7 days, extended 1.5-2 days per mm for >50mm — BS 8204-1
- Typical wastage allowance of 10% for screed — Industry standard practice