Sika 4a Waterstop
  • Sika 4a Waterstop

Sika 4a Water Stop


Sika 4a Water Stop is a ready to use quick setting leak stopping liquid which is mixed with water and ordinary Portland cement to produce a paste for leak stopping against high water pressure infiltration.

VAT excluded

£70.76 Tax incl.


Sika 4a Water Stop is a ready to use quick setting leak stopping liquid which is mixed with water and ordinary Portland cement to produce a paste for leak stopping against high water pressure infiltration.


  • To seal against high and moderate water pressure infiltrations in concrete, rock or masonry
  • Allows Sika 1 Waterproofing Renders, SikaCem 133 Gunite or Shotcrete to be applied on structures exposed to running surface water
  • Basements, pits and pools
  • Concrete, rock and masonry
  • Subways and tunnels

Features and Benefits:

  • Ready to use
  • Rapid setting time
  • Just add water and ordinary portland cement
  • Well proven
  • Does not contain chlorides
  • Suitable for use with potable water

For more details please download the product data sheet from the 'DATASHEETS' tab above.

It is your responsibility to read the Product Data Sheets (available below) before you place an order and prior to application of the product. The content of this website is our best recommendation and is not advice. Coverage rates quoted are approximate, you agree that coverage depends on the condition of the substrate, surface absorption, texture and application method. We ALWAYS recommend a trial area is coated to ensure the product meets your requirements before use.

Product Details

Data sheet

350ml/kg cement (1-1 dilution), 180ml/kg cement (1-4 dilution)

Customer agrees that before placing an Order, Customer has read and understood the most up to date Product Data Sheet for the Product. Where we have access to the Product Data Sheet from the manufacturer, we will either provide a copy on request, or include a link to the Product Data Sheet available on the manufacturer’s website. Customer further agrees that we have no liability for any errors or omissions contained within the Product Data Sheets. For more information, please see our Terms & Conditions of Sale.

questions Basil Whalley on 04/01/2016

I have a crack about 1cm wide down one side of my concrete swimming pool, can you tell me what product I would need to repair it please.


Ensure the area to repair is clean and dry. Prime the bare concrete crack with 405 Tack Primer, and then use 202 Vertical Surface Repair Mortar to make good. Once cured, this can be overcoated with most single or two-pack swimming pool paints.

questions peter howard on 18/06/2015

My swimming pool is leaking - I think the wall behind the mosaic tiling is porous. What Sika product would you recommend?


All tiles and existing render should be removed and then the Sika 1 Waterproofing System should be applied. This is a 3 coat system using Sika 1 Spritz and Bonding Coat Mortar, Sika 1 Render Mortar and Sika 1 Finishing Mortar. Once applied this system can then be over tiled to bring the pool back to the desired appearance. Alternatively, if you wish to try a less disruptive solution first to see if the problem can be dealt with by using a waterproof coating you could prepare the existing tiles by thoroughly cleaning them and abrading to provide an adequate ‘key’ for the coating to adhere to and apply 2 coats of Rust-Oleum 5500 Solvent Free Epoxy @ 6m² per litre/per coat.

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