Coarse Stuff: Traditional Base Coat Lime Plaster & Mortar

Description

The Advantages of Pure Fat Lime

Solid wall buildings constructed before 1919 require materials that work in harmony with their original design. Because this Coarse Stuff is entirely non-hydraulic (fat lime), it cures slowly through carbonation rather than a chemical water set. This provides three critical benefits:

• Vapour Permeability: It allows the building fabric to ‘breathe’, passively managing moisture and preventing the damp issues often caused by modern, impermeable cement renders.
• Flexibility: The natural elasticity of the cured lime easily accommodates the thermal expansion and minor seasonal movements typical of older structures without cracking.
• Self-Healing: Over time, the continuing carbonation process allows the lime to autogenously heal minor micro-fissures.

Best Practices for Application

Working with non-hydraulic lime requires a controlled environment. The material must not be allowed to dry out rapidly.

• Substrate Preparation: All surfaces must be clean. Highly absorbent backgrounds (such as soft historic brickwork or porous stone) must be thoroughly dampened before application to stop the wall from drawing moisture out of the fresh plaster too quickly. If applying over timber laths, wet the laths the day before, and lightly dampen them again two hours prior to starting work.
• Mixing: As a wet-mix product, it simply needs to be “knocked up” (mixed vigorously) in a mechanical mixer for 3 to 5 minutes to restore its workability. Drain off any standing water from the top of the container before mixing.
• Coat Thickness: Apply base coats at a depth of 10mm to 12mm. Never exceed a maximum depth of 15mm in a single application.
• Curing: A general rule of thumb is to allow one day of curing for every 1mm of plaster depth.
• Environmental Protection: You must shield fresh applications from driving rain, frost, strong winds, and direct sunlight. We highly recommend draping the work area with damp hessian sheeting to regulate the curing process.

Estimated Coverage

Coverage will vary depending on the condition of the substrate and the exact thickness applied.

• 25kg Bag: Yields approximately 1.2m² at a 10mm depth.
• 1000kg (1 Tonne) IBC: Yields approximately 48m² to 50m² at a 10mm depth.

Delivery Information: Please note that 25kg bags are dispatched via pallet network, requiring a minimum order of 3 bags.

(For complete health, safety, and technical data, please refer to the downloadable Product Data Sheet).