One Coat Renders for Exterior Finishes

St Astier Natural Hydraulic Lime Mortars (NHL)

These rendering mortars have been specifically designed to maximise speed of application to shorten completion. Normally sprayed (manual application is also possible but in 2 passes), they can be supplied in a range of colours. See our Colour chart. This eliminates the need for painting. The St. Astier One Coat renders are waterproofed but retain high breathability, good elasticity, low capillarity, water absorption and shrinkage.

When sprayed, they can be immediately straightened with a straight edge or a large spatula. The desired finish can be performed within few hours

Finishes: A 15mm coat is sufficient for weather protection (10mm in low exposure areas). Sponge finishes or scratched finishes can be done 2 to 3 hours from straightening.
Smooth finishes (plastic floats): apply a first pass at the thickness required less 4-5mm. A second and final pass will be applied about 2 - 3 hours later (4-5mm) and floated after 1 hour or so.

If a very coarse finish is required (harled or scratched) up to 20mm thickness would be required. It can be sprayed in one pass. Coarse/rustic finishes of 20-25mm are usually achieved in 2 passes when the second pass will be about 8-10mm.

On concrete blocks (Medium-Low suction) the recommended mortar is: MONO ST. ASTIER One Coat Render.
It is also possible to use site mixed pure NHL mortars.
On concrete blocks or other hard backgrounds, 2 coat work is also possible by using INTERCROMEX ready mixed base coat mortar and finishing with Color Chausable.

On lightweight blocks with high suction and clay blocks use only Thermocromex One Coat Render.

For further Guidance, contact your St Astier Distributor.