First clean on new-build render
Modern estate housing is usually finished in thin-coat render over insulation, and it behaves differently to traditional sand and cement. It looks immaculate for a few years and then greens in a way that surprises owners.
Ask us about this
Monday to Saturday, 8am – 7pm
- Check the shaded elevation, not the show frontage
- Keep pressure off thin-coat systems
- Wait for a whole-panel cast rather than spotting
Why it greens sooner than expected
Thin-coat systems sit over insulation, so the surface stays cooler and holds surface moisture for longer after rain. That combination suits algae. It is a maintenance characteristic of the system rather than a fault with the house.
Why pressure is the wrong tool
The coating on a thin-coat system is a few millimetres thick. High pressure removes the aggregate finish, leaves banding and can expose the base coat. Manufacturers of these systems specify low-pressure cleaning for exactly that reason.
Getting the timing right
There is no benefit to cleaning render that is still clean. The first treatment usually makes sense when a shaded elevation starts to show a green cast across a whole panel rather than in patches.
Common questions
- Will cleaning void anything on a new build?
- Render manufacturers generally specify low-pressure cleaning as correct maintenance. Check your own documentation for the system used.
- Does the colour come back?
- On a sound coating, yes. The colour is in the finish, and removing the growth reveals it.
- How often on an estate house?
- Usually every few years, and sooner on the elevation that gets least sun.
Similar situations
Send a photo of the shaded elevation and we will say whether it needs treating yet.
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