Duro Lime Plaster Base Coat

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A general purpose lime undercoat plaster. Suitable for most masonry backgrounds.

Great for renovation, conservation or eco-friendly new builds, it 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.

Duro is applied as a standard base coat plaster and finished with a finishing plaster such as Lime Green Solo or Fine stuff lime putty plaster. 

For situations where extra a lightweith thermally insulating mix is required see our Ultra undercoat, which contains insulating beads.

 

 

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General Information

Duro: Natural is a breathable, elastic and salt resistant undercoat.Duro Natural does not contain PVA or acrylic, cement or PFA or any other materials containing toxins or which reduce breathability. Duro Natural is ideal for most old buildings or newer eco-friendly construction where a pure lime render or plaster is desired.

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. Mix for up to 10 min in 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, but is still "green‟.

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) Base coat 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 maybe 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 lath, please refer to Lime Green.

c) Topoat 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.