Sikalastic 1K Flexible Mortar

Approx read time: 3 minutes

Sika is a global market and technology leader in the development and production of specialist products and systems for construction. The “Repair and Protection” of concrete structures is one of Sika’s core competencies, with the Sika range including concrete admixtures, resin flooring and coating systems, all types of waterproofing solutions, sealing, bonding and strengthening solutions, as well as the complete range of products developed specifically for the repair and protection of concrete structures. These Sika products have all relevant international approvals and are available worldwide through the local Sika companies and our specialist contracting and distribution partners.

During the past 100 years, Sika has gained extensive experience and expertise in all aspects of concrete repair and protection, with documented project references dating back to the 1920’s. Sika provides ALL of the necessary products for the technically correct repair and protection of concrete, ALL of which are fully in accordance with the Principles and Methods now defined in European Standards EN 1504. These include systems to repair damage and defects in the concrete and also to repair damage caused by steel reinforcement corrosion. Special Sika products and systems are also available for use on many different specific types of structures and for carrying out concrete repair works in all different application, climatic and exposure conditions.

Sikalastic®1K is a one component, flexible, fibre-reinforced mortar, based on cement modified with special alkali-resistant polymers. It also contains fine fillers, selected graded aggregates, plus special waterproofing additives to produce a flexible mortar that is ideal for waterproofing surfaces subject to flexural strain. Sikalastic®1K is suitable for application by brush, roller, trowel or spray equipment.


  • Waterproofing of drinking water tanks.
  • Waterproofing and protection of hydraulic structures such as swimming pools, basins, bridges, canals and pipes.
  • Outside waterproofing and protection of basement walls.
  • Inside waterproofing against negative water pressure of basement walls and floors.
  • Waterproofing of balconies and terraces on concrete substrate or old tiles.
  • General waterproofing of surfaces.


  • One component. Just add water.
  • Versatile application with trowel, roller or brush.
  • Good crack-bridging property; maintains its flexible properties over a long time.
  • Potable water approved (AS4020:2005).
  • High mechanical resistance and optimum adhesion on various substrates like: concrete, mortar, ceramic tiles, clay bricks, wood, masonry.
  • Suitable for negative pressure to 25m.
  • Easy to mix: adjustable consistency according to the required application.

Application of Sikalastic®1K

General Application

  • Using a Spatula – Exert good and even pressure onto the substrate
  • Using a Short to medium hair roller – Maintain a homogeneous distribution on the substrate.
  • Using a Brush – Apply in 2 directions (diagonally opposite / cross-wise).
  • Using a Mechanical Sprayer Applicator – Refer to local Sika Technical Department for details.

Applications Over Joints

  • At joints or other critical movement areas (for example junctions with vertical surfaces), the waterproofing should be reinforced by Sika® Seal Tape-S.
  • It must be applied directly on the fresh first layer and then covered by the second layer of Sikalastic®1K.

Applications Under Tiles

  • Ceramic tiles and vitreous mosaics can be applied on Sikalastic®1K using a specific adhesive (e.g. cement based adhesive with maximum flexibility according to Class C2 EN 12004).
  • Joint gaps must be sealed with Sika Ceram range.

Buy online at NHS now!