Render / Stucco Calculator
Render / Stucco Calculator
Rendering a wall or applying stucco? This calculator estimates how much material you'll need, including sand, cement, lime, and plasticiser. Suitable for UK render systems and USA stucco techniques.
Standard Thickness Guidelines
- 🇬🇧 UK Render: 2-coat system (scratch + top coat), typically 10–15mm total thickness
- 🇺🇸 USA Stucco: 3-coat system (scratch + brown + finish), usually 15–22mm total thickness
- Finish textures: Smooth, dashed, roughcast, or trowelled — may slightly affect volume needed
- Always apply in thin coats and allow proper curing between layers
Material Requirements (Based on 10–20mm Thickness)
| Render Depth | Wall Area | Total Volume | Cement Bags | Sand (kg) |
|---|---|---|---|---|
| 10mm | 10 m² | 0.10 m³ | 6 | ~700 kg |
| 15mm | 10 m² | 0.15 m³ | 9 | ~1050 kg |
| 20mm (USA 3-coat) | 10 m² | 0.20 m³ | 12 | ~1400 kg |
Pro Tips
- Pre-wet the wall before applying the scratch coat
- Use corner beads and mesh for strength and edge straightness
- Always overestimate slightly to allow for waste and rough surfaces
Common Mistakes
- Applying too thick in one pass — leads to cracking and poor adhesion
- Ignoring regional differences in base coat requirements
- Not using lime or plasticiser — can result in stiff, unworkable render
FAQs
- Can I use this for one-coat render systems? → Yes — just enter total wall area and 10–15mm thickness
- Does USA stucco need lath? → Yes, metal lath or mesh is required over timber/OSB substrates
- Do I need a curing period? → Yes — minimum 24–48h between coats; longer in cold or humid weather
