Description
Sikalastic-1K (also labelled Sikalastic-1 Komponent) is a one-component, cement-based waterproofing membrane for wet areas, balconies, tanks and below-ground walls, supplied here in a 10kg pail that suits small to medium jobs. You only add water, then apply it by brush or trowel to form a flexible, crack-bridging, fibre-reinforced coating that protects concrete and prepares surfaces for tiling.
About the formula
A fibre-reinforced mortar based on cement modified with alkali-resistant polymers, plus selected aggregates, fine fillers and additives. The consistency can be adjusted with the amount of water, so it can be made thinner for brushing or stiffer for troweling. It has good sag resistance on vertical surfaces, bonds well to concrete, cement mortars, stone and masonry, and can be applied on damp substrates. Sika lists it as meeting AS/NZS 4020 for products in contact with drinking water.
Where to use it
Indoors: bathrooms, showers and laundries before tiling with a cement-based tile adhesive; flexible protection of concrete tanks, basins and pipes; waterproofing walls and floors in basements against negative water pressure.
Outdoors: terraces and balconies before tiling; swimming pools before tiling; external wall surfaces that will be backfilled in ground; protective coating for reinforced concrete exposed to freeze-thaw and carbon dioxide attack.
Suitable substrates include concrete, cement mortars, stone and masonry. Substrates must be structurally sound and clean, and all joints and gaps must be sealed before coating.
How to use it
Prepare the substrate so it is sound and free of dust, oil and loose material, and seal any joints or gaps. Add water to the powder and mix with a low-speed mixer until smooth. For a 10kg pail, Sika's current data sheet gives about 3.0 litres of water for brush application and about 2.2 litres for trowel application. Apply in at least two layers: no more than about 1mm per layer by brush or 2mm per layer by trowel. Sika specifies a total dry film thickness of about 2mm for standard applications and 3 to 4mm for negative-pressure or immersed applications. When brushing, work in two directions, crosswise. Mixed material has a pot life of about 30 minutes at 20°C. Clean tools with water before the material sets; hardened mortar can only be removed mechanically.
Important notes
Apply only when air and substrate temperatures are between 5°C and 35°C. The membrane must be completely hardened before tiling, overcoating or water contact. At 20°C, Sika's guide is about 2 days before tiling, painting with a water-based coating or immersion in water, and longer in cooler conditions (about 3 to 7 days at 10°C depending on the use). Allow about 15 days before contact with drinking water. Tile over it with a polymer-modified, cement-based tile adhesive from the Sika range. Times vary with temperature and humidity. Consumption depends on substrate roughness; as a guide, about 1.2kg per m² per mm of thickness. Store in the original sealed pail in cool, dry conditions and protect from water. Check the production date, as the current Sika data sheet gives a shelf life of 6 months. Always follow the current Sika product data sheet for your application.
Specifications
| Brand |
Sika |
| Product |
Sikalastic-1K (Sikalastic-1 Komponent) one-component cementitious waterproofing mortar |
| Pack |
10kg pail |
| Colour |
Light grey |
| Base |
Cement modified with alkali-resistant polymers, with fibres |
| Application |
Brush or trowel (mix with water) |
| Pot life |
About 30 minutes at 20°C |
| Application temperature |
5°C to 35°C (air and substrate) |
| Fresh mortar density |
About 1.5 kg/L |
| Consumption |
About 1.2 kg/m² per mm (guide) |
| Water contact |
About 2 days at 20°C before immersion; about 15 days before drinking water contact |
| Approvals |
AS/NZS 4020 (contact with drinking water) |
| Use |
Interior and exterior |
Safety
Wet and dry cement products can cause serious eye damage, so wear safety glasses or a face shield, protective gloves and long sleeves, and avoid breathing dust when handling and mixing. For skin contact, remove contaminated clothing and wash with soap and water. Keep out of reach of children, and do not eat, drink or smoke while using it. Refer to the Safety Data Sheet (SDS) for full details.
