Wrimco Waterproofing                              Home  | Specification | Product | Project | Technical data A-Z | Contact us

Adhesive Membrane

Anti-root Membrane

Approved Applicators

Backing Rod

Drainage Cell

Drainage Sheet

Epoxy Adhesive

Epoxy Flooring

Flat Roof Membrane  

Foundation Membrane

Liquid Membrane

Membrane Protection

Product Application

Product Category

Retaining Wall

SBS Sheet Membrane

Torch on Membrane

Under Slab Membrane

Vapour Barriers

Waterproofing Primer


Waterproof Balcony Liquid Membrane Waterproof Bathroom liquid membrane Waterproof Retaining Wall Liquid Rubber Membrane How to waterproof a bathroom Waterproof Internal Wet Area Membrane Waterproof Tiled Balcony Clear Penetrating Sealer Trafficable liquid membrane UV Protection liquid membrane Waterproof Water Feature liquid membrane Hydro Pressure Resistant liquid membrane Waterproof Shower Recess liquid membrane Repair Roof Gutters liquid Membrane Waterproof Planter Box liquid membrane Waterproof Under Tiles Liquid Membrane Waterproof Water Tanks liquid membrane waterproof Flat Roof liquid membrane Waterproof fish pond liquid membrane Waterproof Swimming Pool  How to stop tiled deck leaking waterproof bathroom liquid membrane Waterproof Leaking Shower Tradesman Waterproof Leaking Balcony Liquid Membrane Waterproof Damp Basement Wall Liquid Membrane Crystoflex Max Cementetious waterproofing membrane Waterproof Under Screed Liquid Membrane Waterproof above screed liquid membrane How to waterproof a Planter Box How to waterproof a shower How to waterproof tiled balcony Waterproof Roofs with UV liquid membrane How to waterproof a metal roof Sikalastic 560 - Repair Bitumen membrane Roof How to waterproof a planter box Waterproof Flat roof liquid membrane Below Grade Membrane UV Resistant Polyurethane Membrane Waterproof leaking balcony liquid membrane waterproof damp basement wall liquid membrane Solutions to common waterproofing problems Maxseal Foundation Mapelastic Smart Membrane Polyurethane Membrane MasterSeal M210TIX Latex Rubber Liquid Membrane Waterproof wet basement wall liquid membrane Waterproof leaking Basement Tradesman Waterproof Building Contractors Waterproof Lift Pit Contractors Waterproof leaking Internal Wall tradesman Waterproof leaking deck tradesman waterproof leaking roof, gutters, balcony, car park tradesman Waterproof leaking Box Gutter Tradesmen Waterproof leaking External Wall tradesmen Waterproof Swimming Pool Contractors Waterproof Garage Roof Liquid Membrane Injection Drill Pump Vulkem 350/345/346 Ardex WPM 300 Epoxy - Stop Rising Damp Ardex WPM300 Waterproof Metal Roof Liquid Membrane Waterproof Leaking Under Tiles Liquid Membrane Repair Leaking Balcony, Flat Roof, Planter Box, Bathroom Waterproofer, waterproof Leaking Balcony, Flat Roof, Planter Box, Bathroom tradesman, handyman Waterproof exposed balcony liquid membrane Hydrostatic Pressure resistant Liquid Membrane Waterproof Box gutter liquid membrane Prevent Rising Damp Waterproofing Epoxy Waterproof leaking metal roof tradesman Waterproof Retaining Wall liquid membrane Waterproof Underground Walls liquid membrane Waterproof Internal, External Wall Liquid Membrane Waterproof Concrete Slab Liquid Membrane Waterproof Balcony Liquid Membrane Stop Leaking Shower Liquid Membrane How to repair a leaking fish pond Waterproof Wet Retaining Wall Liquid Membrane Waterproof Aluminium Roof Liquid Membrane How to waterproof a retaining wall How to waterproof a Retaining Wall Waterproof cement screed epoxy Vulkem 360NF Waterproof Car Park Liquid Membrane Waterproof Retaining Wall liquid membrane Waterproof Besser Block Wall Liquid Membrane How to fix leaking fish pond Waterproof Garage Roof Liquid Rubber Membrane Trafficable UV resistant liquid membrane Stop Basement Wall Leaking UV Resistant Polyurethane Liquid Membrane Waterproof water tanks for drinkable water Waterproof Commercial Roof, Balcony Contractors
Commercial Building Sheet Membrane Concrete Roof Sheet Membrane Waterproof Deck Sheet Membrane Entertainment building Waterproofing Membrane Waterproof Government Building Sheet Membrane Waterproof Hospital Building Sheet Membrane Waterproof Landmark Building Bitumen Membrane Waterproofing Planter Box Sheet Membrane Waterproof Plywood Roof Sheet Membrane Waterproof Residential Building Sheet Membrane Waterproof Roof Bitumen Sheet Membrane Waterproof Flat Roof Sheet Membrane Waterproof Retaining Wall Sheet Membrane Terrace waterproofing Sheet Membrane Waterproof University Building Sheet Membrane Wrimco Reference Waterproof Lift Pit Sheet Membrane Waterproof Car Park Roof Sheet Membrane Waterproof Concrete Slab Sheet Membrane Waterproof Concrete Roof Sheet Membrane Tanking Sheet Membrane Systems Vaucluse Waterproofing Project  Mosman Waterproofing Project Waterproofing Palm Beach Waterproofing Dover Height Waterproofing Darling Point Waterproofing Bellevue Hill waterproofing tradesman Under Concrete Slab Waterproofing Knowledge Base FAQ Waterproofing Product Waterproof Leaking Swimming pool tradesman Waterproof Leaking Garage Roof tradesman Repair SBS, APP Sheet Membrane Waterproof Concrete Slab Sheet Membrane Waterproof Leaking Garage Roof Liquid Rubber Membrane Waterproof Leaking Metal Roof Liquid Rubber Membrane Polyurethane Modified Acrylic Liquid Rubber Membrane Waterproof Balustrade Sheet Membrane Waterproof Commercial Building Project Bitumen Sheet Membrane Waterproofing Membrane Protection Drainage Cell Closed Cell Backing Rod Repair Crack Joints Closed cell backer rod Expansion joint backing rod Backing Rod waterproof leaking laundry tradesman Repair Leaking underground basement wall Waterproofer Waterproof leaking planter box tradesman Waterproof Leaking Shower Tradesman Waterproof Planter Box Tradesman Waterproof Leaking Box Gutter Tradesman Waterproof Leaking Balcony Tradesman Waterproof Leaking Fish Pond Tradesman Repair Construction Building Contractors
Hydrostatic Pressure resistant Liquid Membrane :

Sikalastic -1K (au) One component cementitious mortar fibre reinforced for flexible waterproofing  

Product Description  

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.  


  • Protection of concrete surfaces according to EN 1504-9, principles 1: protection against penetration (coating); 2: control of moisture (coatings); and 8 increasing resistivity (coating)
  • Waterproof protection of concrete structures including tanks, basins, pipes, etc.
  • Waterproofing external wall surfaces to be backfilled in ground
  • Internal waterproofing of walls and floors, in basements
  • Waterproofing of terraces and balconies over concrete or prepared existing tiles
  • Flexible protection coating for reinforced concrete structures against the effects of de-icing salts, freeze-thaw and carbon dioxide swell consolidation.   

Characteristics / Advantages   

  • Suitable for negative pressure to 25m
  • Can be applied on damp substrates
  • Easy to apply by brush, roller, trowel or spray equipment
  • Good sag resistance and easy to apply, even on vertical surfaces
  • Good crack-bridging properties
  • Very good adhesion on many substrates including concrete, cement mortars, stone, ceramics, bricks and timber
  • Mixing ratio can be adjusted in order to obtain the consistency and workability desired for the intended application   

Approvals / Standards: AS4020:2005 - potable water  

Product Data  

Colours: light grey

Packaging: 20kg bags & 10kg pails  


Storage Conditions / Shelf-Life: 12 months from the date of production, if stored properly in the original packaging, in cool and dry conditions. Protect from water.  

Technical Data   

Chemical Base: Cement modified with polymers, selected aggregates, admixtures, additives and fibres.

Mixed Density: ~1.5 kg/l

Grading: : 0.125 mm  

Mechanical Properties   

Resistance against water pressure:

positive: 3.0 bar, EN 12390-8, with exposition time modified to 5 days

negative: 2.5 bar,  Internal test according to EN 14891:2007 and DIN 1048-5:1991 with time modified to 6 days  

Behaviour after immersion in salt water:

Adhesion to concrete after curing for 1 week at 20 C and R.H. 60% and then immersion in solution of 35g of sodium chloride for each litre of water (similar to sea water) 

  • immersion for 1 month 1.90 MPa (EN 1542)
  • immersion for 3 months 1.52 MPa (EN 1542)
  • immersion for 6 months 1.22 MPa (EN 1542)
  • immersion for 1 year 1.15 MPa (EN 1542)   

Application Details   

Consumption: ~1.2 kg/m2/mm thickness

Substrate Quality: Substrates must be structurally sound, clean, dry and free of all contaminants such as dirt, oil, grease, coatings and other surface treatments, etc.

Substrate Preparation: Clean surfaces by blast cleaning, high-pressure water-jetting (400 bar), wire-brushing, grinding and abrading of ceramic tiles etc., in order to remove all previous coatings, any traces of grease, rust, release agents, cement laitance and any other material which could reduce adhesion. All dust deposits from this preparation must also be removed i.e. by vacuum.

Repair concrete substrates, if necessary, with an appropriate cementitious mortar from Sika MonoTop range of repair materials.

The substrate must be adequately dampened before application  

Special Requirements   

All connections between the substrate and pipe entries, plant and equipment, light switches etc., must be sealed and watertight. Joints in concrete, pipes, anywhere else in the structure must also be sealed and made watertight.

Use coved details at the floor/wall junctions

Avoid any stagnant water presence or condensation / ponding on the surfaces before application.  

Application Conditions / Limitations    

  • Substrate Temperature: min. + 5 C; max. + 35 C
  • Ambient Temperature: min. + 5 C; max. + 35 C   

Application Instructions /  Water Dosage: 

  • application by roller: ~ 7 litres water per 20 kg bag
  • application by brush: ~ 6 litres water per 20 kg bag
  • application by trowel: ~ 4.4 litres water per 20 kg bag
  • Note: Product should be gradually added to water while mixing until homogenous. 

Application Method / Tools   

Apply Sikalastic -1K by:

1) spatula, exerting good and even pressure onto the substrate;

2)short-medium hair roller, maintaining a homogeneous distribution on the substrate;

3) brush, in 2 directions (diagonally opposite / cross-wise);

4) mechanical spray: refer to local Sika Technical Department for details

Maximum recommended thickness is 2 mm per coat. The final thickness when applied by trowel will depend on the method of application and level or grade of exposure / waterproofing required.

For demanding applications including negative pressure. The optimum waterproofing performance is obtained by applying Sikalastic -1K by trowel in at least 2 layers, to a total thickness of 3-4mm. For general applications 2 coats of minimum 1mm is recommended.

Application by brush or roller must be undertaken with the maximum attention to uniformly covering the whole surface. The maximum recommended thickness for these methods of application is 1 mm per layer. In these situations, the application of min. 2-3 layers is required. Wait until the first layer is dry before applying subsequent layers.

Do not blast clean or abrade before complete hardening of the material damaged. Wait for complete hardening, and then remove any roughness by light sanding.


At joints or other critical movement areas (for example junctions with vertical surfaces), the waterproofing can 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.


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). Joints gaps must be sealed with specific cement based products such as found in the Sika Ceram range.  

Cleaning of Tools: Tools should be thoroughly cleaned with water before the material has set. Hardened mortar can be only be removed mechanically.  

Pot Life: ~ 30 min.@ +20 C

Sikalastic -1K must be completely hardened before over-coating or water contact.

Guide for waiting times at the following temperatures:

                                                 +20oC        +10oC

  • 1) Horizontal covering by tiles        ~2 days     ~7 days
  • 2) Vertical covering by tiles           ~2 days     ~3 days
  • 3) Water emulsion coating             ~2 days     ~3 days
  • 4) Immersion in water                  ~2 days     ~7 days
  • 5) Contact with drinkable water      ~15 days   ~15 days

Times will vary due to ambient and substrate humidity  

Notes on Application/ Limitations:

1) Sikalastic -1K cannot be smoothed using a float or trowel

2) protect from rain for at least 24-48 h after application;

3) avoid direct contact with chlorinated water i.e. in swimming pools, by using suitable protection e.g. ceramic covering;

4) avoid application in direct sun light, when rain is imminent or in strong winds;

5) Setting time can be influenced by high relative humidity, particularly in closed rooms or basements. The use of adequate ventilation is recommended;

6) Before contact with drinking water, ensure the Sikalastic -1K is completely hardened and wash carefully to remove dust, loose material or stagnant water in accordance with Italian regulation.

7) Sikalastic -1K is permeable to water vapour and does not form a vapour barrier for resin based systems not permeable to gas

8) If a solvent based paint is to be applied on Sikalastic -1K, carry out preliminary testing in order to ensure the solvents do not attack and damage the waterproofing layer.  

Health and Safety Information:

For information and advice on the safe handling, storage and disposal of chemical products, users shall refer to the most recent Safety Data Sheet containing physical, ecological, toxicological and other safety-related data  .


Waterproofing FAQ

Membrane Protection Board

Waterproofing Coating

Waterproof Drainage Sheet

Waterproofing Primer

Repair and Maintenance