Screed Calculator, South Africa
Work out cement, sand and cost for a traditional sand:cement floor screed, or bags needed for a self-levelling compound.
Quick answer: Standard sand:cement floor screed uses roughly 11kg cement and 28 litres of sand per m² at 25mm thickness (Concrete Institute SA, SANS 10109-2), plus 10% wastage. Self-levelling compound coverage depends on the product, thin levelling compounds and structural self-levelling screeds have different maximum thicknesses per pour. Installed screed costs approximately R180–R500/m² in 2026 depending on type and finish.
⚠️ For planning purposes only. Confirm exact mix ratios and pricing with your supplier before ordering.
How to Use This Calculator
Select traditional sand:cement screed for a hand-floated floor, or self-levelling compound if you're using a bagged, pre-mixed pouring product.
Enter the area in square metres and your intended screed thickness in millimetres. For self-levelling compound, also choose thin levelling compound or structural self-levelling screed, since coverage and maximum thickness per pour differ between the two.
Screed vs concrete vs plaster: what's actually different
Screed is a thin, aggregate-free sand:cement layer laid over a structural concrete slab to create a smooth, level surface ready for tiling, flooring or carpet. It's easy to confuse with two other materials on this site. Concrete is the structural slab itself, poured thick with coarse aggregate to carry load, screed sits on top of that slab and does no structural work at all. Plaster uses a similar sand:cement family of mixes but is applied to walls and ceilings, not floors. If you're pricing a full build, you likely need all three calculators for different parts of the job, not one for all of them.
Sand:cement screed mix ratio and coverage
The Concrete Institute's own SANS 10109-2 reference gives a floor screed mix of 3.5 parts sand to 1 part cement by mass. On site, that translates to roughly 130 litres of moist, loose sand per 50kg bag of cement. This ratio holds regardless of whether the screed is bonded, monolithic or unbonded, only the thickness changes by type (see the table below). At 25mm thickness, that mix works out to approximately 11kg of cement and 28 litres of sand per square metre, before adding the recommended 10% wastage allowance. A single 50kg bag of cement covers roughly 4.5m² at 25mm before wastage.
Worth flagging honestly: not every source agrees on the sand quantity. AfriSam's own online calculator implies a noticeably leaner cement content relative to sand than the Concrete Institute figure used here. Treat the cement quantity above as reliable and the sand quantity as a reasonable estimate, your exact supplier's mix may vary, so confirm before a large order.
Screed thickness by application
| Application | Thickness | Notes |
|---|---|---|
| Monolithic | 15–40mm | Laid while the base slab is still wet |
| Bonded | 25–50mm | Onto a hardened concrete slab, most common residential case |
| Unbonded, on DPM | 50mm+ | Over a damp-proof membrane |
| Unbonded, over insulation | 70mm+ | Underfloor heating or other compressible layer |
Self-levelling compound: a different product, different maths
Self-levelling compound is a pre-mixed bagged product you pour and it settles flat under its own weight, rather than being hand-floated like traditional screed. Coverage depends heavily on the specific product. A thin levelling compound (used to smooth minor imperfections before flooring goes down) typically covers around 4m² per 20kg bag at 2.5mm, and shouldn't exceed 3 to 4mm per application. A thicker structural self-levelling screed covers a broadly similar rate per millimetre but can be poured up to 10mm in a single application. These are not interchangeable products, always check your specific brand's datasheet before ordering in bulk.
Screed cost per m² in South Africa (2026)
Screed pricing varies by region, screed type and whether you're pricing materials only or a full installed job. DIY materials-only sand:cement screed runs roughly R80–R120/m². A professionally installed standard residential screed typically costs R180–R250/m², while self-levelling or commercial-grade screed installed by a contractor can run R350–R500/m² or more. These are market rates from SA trade sources, not a fixed price list, always get a local quote to confirm before budgeting.
A worked example: 45m² bonded screed at 30mm
Take a 45m² room needing a bonded screed at 30mm thickness. At 0.44kg cement and 1.12 litres of sand per m² per mm, the base quantities are 45 × 30 × 0.44 = 594kg cement and 45 × 30 × 1.12 = 1,512 litres of sand. Adding the 10% wastage allowance brings that to roughly 654kg cement, which means 14 bags of 50kg cement (13.08 rounds up, since a supplier only sells whole bags), and 1,664 litres (1.66m³) of sand. At R180–R250/m² installed, budget roughly R8,100–R11,250 to have this room professionally screeded, or R3,600–R5,400 materials-only if doing it yourself.