Choosing a render finish for external wall insulation
The short answer
Most EWI is finished in through-coloured silicone render, which sheds water and stays clean. Mineral and silicate renders suit breathable systems, pebbledash keeps the look of a dashed street, and brick slips or cladding avoid a rendered look altogether.
The main options
- Silicone render: water-repellent, low-maintenance, huge colour range. The usual choice on EPS.
- Mineral and silicate render: very vapour-open, matt finish; mineral renders are painted.
- Pebbledash (dry dash): chippings thrown into wet render, ideal where the street is dashed.
- Brick slips: real clay slips for a brick appearance.
- Cladding: composite, fibre cement or timber on battens over insulation.
Colour and texture
Grain sizes of 1.0–2.0mm change how smooth the wall looks and how much it hides. Very dark colours absorb heat and stress the system, so most system holders set a minimum light reflectance value; dark plinths and bands are usually fine. Always see a sample on your wall in daylight.
Upkeep
Silicone render needs an occasional gentle wash, and a biocide treatment if algae appears on shaded walls. Mineral render is repainted every 8–12 years. Dash and brick slips need very little.
Related services
Questions people ask
What's the most popular colour?
Off-whites and light greys, often with a darker grey plinth.
Can I change colour later?
Yes, with a compatible paint system over the render.