About EWI-269 Lightweight Basecoat
EWI-269 Lightweight basecoat is a breathable, heritage friendly basecoat. Once dry, the adhesive provides a strong, flexible (when used for basecoat) and waterproof layer. The Lightweight Basecoat can be applied internally or externally on the following substrates:
- Ziegel Blockwork e.g. Porotherm, Thermoplan, Juwo blocks & Poroton Block;
- Autoclaved aerated concrete blocks e.g. Ytong;
- Calcium Silicate blocks;
- Stone e.g. Sandstone, limestone and natural stone;
- Solid brick walls
Preparing EWI-269 Lightweight Basecoat
The Lightweight Basecoat comes as a dry mix in 25kg bags. The bag needs to be mixed with 5 litres of clean potable water using an electric paddle mix. It is recommended the basecoat is mixed for 2-3 minutes to achieve the required consistency. The Lightweight Basecoat is then ready for use. When hardened, the Lightweight Basecoat should not be remixed with fresh material.
Applying the Lightweight Basecoat
The basecoat should be applied to the substrate using a plastering trowel or spray machine. The basecoat can be applied in either a single pass or multiple layers depending on the finish required. The maximum recommended depth of a single pass of the Lightweight Basecoat is 25mm.
Application conditions for Lightweight Basecoat
- Substrate primer: EWI- 301 or EWI-310 if a key is required.
- Application temperature (air, substrate, materials): from +5°C to +25°C
- Water mix proportions: approx. 5 litres of water per 25 kg of dry mix
- Time of usability after mixing with water: approx. 2 hours (temp. +20°C)
- Quantity to be used: approx. 4-5 kg/m2
Coverage Rates for Lightweight Basecoat
At 5mm thick, 5.5kg of dry mix basecoat will cover approximately 1m²
Technical Specifications of Lightweight Basecoat
- Composition: Portland cement, hydrated lime, mineral fillers (including perlite), admixtures
- Density once set: Approx 1.2 g/m3 class LW1
- Density of fresh mortar: Approx 1.5 g/m3
- Air content: Approx 29%
- Compressive Strength after 28 days: CSII
- Thermal conductivity coefficient (λ) (tabular value):
• 0.47 W/m*K
- Water vapour diffusion factor: 7.8
- Reaction to fire: A1
- Grain size distribution: up to 1.25mm
- Adhesion to substrate and symbol of cracking model:
≥ 0.4 MPa; FP: B
- Capillary water absorption: category W0
Safety Measures of Lightweight Basecoat
- Wear protective clothing during use.
- Avoid contact with eyes.
- Avoid contact with skin for extended periods of time.
- Always ensure that water and/or washing facilities are available on site.
Storage conditions of Lightweight Basecoat
Comes in powder form in a 25kg paper bag.
Store in a cool, dry place. Avoid ingress of water. Shelf life: up to 12 months from the date of manufacture.