Render & Stucco Calculator — Base Coat, Mesh & Finish
Calculate kg of base coat render, finish coat, reinforcing mesh and primer for rendered facades and ETICS systems. Covers traditional lime-cement render, monocouche and thin-coat silicone or mineral finish.
How the render calculator works
- 1Facade area = wall or ETICS board area (m²), minus window reveals if embedded
- 2Base coat (adhesive + leveling): area × kg/m² rate (typically 5–8 kg/m² at 6–8 mm)
- 3Reinforcing mesh: area + 15% for laps at corners (100 mm min. lap) and openings
- 4Primer: area ÷ coverage rate (typically 6–8 m²/kg)
- 5Finish coat: area × kg/m² (thin-coat silicone: 2–3 kg/m², monocouche: 10–12 kg/m²)
- 6All materials sold by the bag or kg — round up to nearest bag
Worked example
ETICS system on 80 m² facade. Base coat 6 kg/m², silicone finish coat 2.5 kg/m². Mesh 160 g/m².
Base coat: 80 × 6 = 480 kg (24 bags of 20 kg). Mesh: 80 × 1.15 = 92 m². Finish coat: 80 × 2.5 = 200 kg (10 bags). Primer: 80 ÷ 7 = 12 L.
Frequently asked questions
How much render do I need per m²?
Traditional 2-coat lime-cement render at 15 mm total: approximately 22–25 kg/m². Monocouche one-coat system: 10–12 kg/m² at 15 mm. Thin-coat silicone or acrylic finish: 2.5–4 kg/m² at 1.5–3 mm.
What is the difference between render and plaster?
Render is applied to external walls — it must be weather-resistant, vapour-permeable and frost-proof. Plaster is used internally — it is more refined, less weather-resistant and typically thinner (6–12 mm vs 10–20 mm for render).
Do I need mesh in render?
Reinforcing mesh is mandatory in all ETICS/EIFS systems to prevent cracking. It is also recommended in traditional render at re-entrant corners, over mixed substrates and where movement joints are required. Use alkali-resistant (AR) glass fibre mesh.
What is monocouche render?
Monocouche (single-coat) render is a factory-mixed pre-coloured render applied in one 12–15 mm coat directly over the substrate. It is faster than two-coat systems and eliminates a separate paint finish — available in a wide range of colours.
How long does render take to dry before painting?
Traditional cement render: 28 days minimum before applying masonry paint. Monocouche does not require painting. Thin-coat silicone finish is the final coat. In cold or damp weather, curing times can double — protect fresh render from rain, frost and direct sun.