Leaking cracks & active water seepage

The work, step by step

General guidance based on the manufacturer data sheets. Site conditions differ: confirm the system with MCT before you start. Where we do not name a product, ask us and we will confirm the right one.

1. 1

   Step 1: Find the source and check the structure

   Note whether water runs or only seeps, and whether the crack is in a load-bearing member; structural cracks also need an engineer (see structural-cracks). Before curtain injection near buildings, survey the site and foundations and check there are no drains or open pipes near the injection areas (Injection-306 p.2).

2. 2

   Step 2: Stop running water

   For holes and static cracks with running water, cut a square or undercut slot at least 19 mm wide and deep (no V-cut), mix SikaSet Waterplug for no more than 30 seconds, place within 3 minutes and hold it until set (Waterplug p.2, p.3). Or mix Sika-4a with cement into a plug by gloved hand; under heavy flow, divert water through plastic tubes first (Sika-4a p.2).

   SikaSet Waterplug Sika Request a quotation

   Non-moving (static) cracks and holes with running water or moisture seepage For immersion service For anchoring vertical bolts Basements Foundations Retaining walls Sewers Locations Vertical, overhead, or horizontal Interior or exterior Above or below grade… (TDS p.1)

   Sika-4a Sika

   Sika®-4a is used as preliminary waterproofing work on wet surfaces or where there is general infiltration of water, prior to the application of subsequent cementitious render or gunite. (TDS p.1)

   Temperature stated in TDS

   +5 °C min. / +35 °C max (TDS p.2)

3. 3

   Step 3: Inject the crack

   Sika Injection-306 is a very low-viscosity, elastic polyacrylic resin for water-bearing cracks, voids and joints, and tolerates minor movement (Injection-306 p.1). Its reaction time is adjustable from 10 to 60 minutes and must be checked on site before injecting (p.1, p.3). Experienced professionals only (p.1).

   Sika Injection-306 Sika Professionals only Request a quotation

   Crack and joint injection Injection of SikaFuko® injection hoses to seal construction joints Sealing water-bearing cracks and voids Sealing all types of leaking building components in damp or water saturated ground conditions Sealing leaks where there is so… (TDS p.1)

   Temperature stated in TDS

   +5 °C min. / +40 °C max (TDS p.2)

4. 4

   Step 4: Structural epoxy only once dry

   Sikadur-52 LP is not for wet injection (Sikadur-52 LP p.2). Once the crack is permanently dry and an engineer needs a structural bond, follow the Structural cracks guide.

5. 5

   Step 5: Waterproof the surface

   Coat the treated area with a cementitious waterproofing that resists water pressure: Sika Thoroseal Plus resists positive and negative pressure; patch holes and cracks with Waterplug first (Thoroseal Plus p.1, p.2). Or SikaTop-107 Seal PK, two coats, no more than 2 kg/m² per coat (SikaTop-107 p.2).

   Sika Thoroseal Plus Sika Request a quotation

   Diverse building substrates Walls Foundations Tunnels Basements Blocks, bricks, stone and concrete Concrete High tanks Interior and exterior (TDS p.1)

   Pack

   35 lb (15.9 kg) pail

   Other options for this stepAsk us

   The right product here depends on your site. We confirm it before naming it.

6. 6

   Step 6: Seal moving cracks and joints

   Where a crack or joint keeps moving, bridge it with Sikadur-Combiflex SG-20 P tape, made for joints and cracks in basements and water-retaining structures, bonded with Sikadur-31 DW (Combiflex SG-20 P p.1, p.3). Professionals only (Sikadur-31 DW p.1).

   Sikadur-Combiflex SG-20 P Sika Request a quotation

   Sikadur-Combiflex® SG-20 P is used for sealing: Movement joints, Construction joints, Pipe penetrations, Cracks, Building components where differential settlement is expected Sikadur-Combiflex® SG-20 P is used for the following areas:, Tunnels. (TDS p.1)

   Temperature stated in TDS

   +40 °C -30 °C (TDS p.2)

   Sikadur-31 DW Sika Professionals only Request a quotation

   Structural adhesive for bonding: Concrete elements, Hard natural stone, Ceramics, fibre cement, Mortar, Bricks, Masonry, Steel, Iron, Aluminium, Wood. (TDS p.1)

   Temperature stated in TDS

   +10 °C to +30 °C (TDS p.1)

7. 7

   Step 7: Drinking-water tanks

   If the leak is in a drinking-water tank, finish with a lining whose TDS states potable suitability: SikaTop-550 Seal or Sikagard PW (06 F2); Sikagard PW is for experienced professionals only (Sikagard PW p.1). Follow local cleaning and disinfection rules (Sikagard PW p.3). See the water-tank guides.

   SikaTop-550 Seal Sika

   As a waterproof lining for water retaining structures. (TDS p.1)

   Temperature stated in TDS

   +5°C min. / 40°C max (TDS p.2)

   Sikagard PW Sika Professionals only

   Chemical resistant protective layer on concrete, structural cementitious mortars, epoxy cement, epoxy resin based products and steel Protection of concrete surfaces / foundations below ground level Lining in storage tanks, manholes, intakes and silos etc. (TDS p.1)

   Temperature stated in TDS

   +5 °C min. / +40 °C max (TDS p.2)

Steps and product facts are taken from the manufacturer data sheets (page cited). Products are named only where the data sheet confirms the use; quantities follow a site visit or photos. General guidance: check the data sheet or ask us before you start.