A general purpose lime undercoat plaster. Suitable for most masonry backgrounds.
Great for renovation, conservation or eco-friendly new builds, Duro lime undercoat offers superior levels of breathability – perfect for walls with damp or salt problems since water can evaporate easily and does not remain trapped where it can damage stone, brickwork and wood.
Duro lime plaster base coat is also flexible and long-lasting, so it’s more resilient to cracking or crazing compared with a site mixed lime render.
Availability
25kg bags, 40 per pallet shrink-wrapped.
Coverage
Approximately 1.7kg per mm of thickness over 1m². One 25kg bag will cover approx. 1.5m² at 10mm thick. This does not include any allowance for wastage.
Surface Preparation Remove dust, surface contaminants and loose or friable existing render/plaster. Where necessary consolidate. Using PVA is not normally appropriate. Ensure Masonry is not waterproofed or painted. Ensure downspouts are not leaking on to the substrate.
Mixing
Add the whole bag of pre-mix into drum mixer carefully avoiding creating excessive dust. Add only 4-5 litres of clean water to each 25 kg sack of Duro base coat. Mix for up to 10 min in the mixer, or use a mechanical whisk for 2-3mins, stand for 10 minutes, then mix once more before application. Do not anything other than clean water.
Application Guidelines
The number of coats is dependent on the surface to which the render is applied, the exposure of the building and the finish required. Please consult lime green for more information. Temperatures: above 5°C and below 30°C. Reworking: up to 8 hours Further coats: after 2 to 7 days, once the coat has stiffened/hardened.
Curing: cure each coat (see below) before further work
a) Stipple and dubbing coats (optional): Apply Lime Green Natural Stipple coat on dense impervious backgrounds (see separate datasheet). Dub out deep holes with Duro Natural and key.
b) Basecoat and floating coats: Apply an undercoat of Duro Natural between 9 to 12 mm thick directly to a prepared substrate. Each coat must be scratched to give a good mechanical key before further coats are applied. If the substrate is too dry, dampen down the surface prior to coating. A second undercoat may be applied after the previous has adequately cured. Ensure it is thinner than the first. Key the final coat of Duro Natural, whilst still green, with a “nail” or “devil” float before applying the topcoat.
N.B. For application to the lath, please refer to Lime Green.
c) Topcoat: Apply Lime green Solo, once the backing coats have had sufficient time to cure. See separate datasheet for more details.
Curing
Prevent all coats from drying out too rapidly. Lightly spray each coat with water if it is hot or the product is drying too quickly.