In construction projects, the importance of below-grade waterproofing is vital. It protects the building or structure from water damage and structural deterioration caused by moisture penetration. However, selecting, designing and installing the appropriate below-grade waterproofing system is critical, as small mistakes can lead to significant problems and costs down the line.

Careful consideration of site conditions, project design, and the specific waterproofing system and materials is necessary to ensure the longevity and reliability of the system.

With the right approach, below-grade waterproofing systems can provide long-term protection against water intrusion and safeguard the structural integrity of the building or structure.

Nowadays, new building owners generally request a service life of at least
50 years.
A waterproofing system usually costs less than
1%
of the total cost of building a structure.
However, choosing a good quality waterproofing solution can save this amount or more in future maintenance and repair costs over the structure's lifespan.
Sika’s expertise is combined with over
100 years
of experience from all around the world in providing successful waterproofing solutions.

Systems + Knowhow

Sika waterproofing solutions protect basements and underground structures from water infiltration and damage, making these spaces more comfortable to live in and giving more possibilities for use of the space. Using Sika solutions can lower the overall cost and increase the long-term durability and lifespan of the project.

Our fully integrated and compatible system solutions are sustainably produced and well proven in projects all over the world, where they have been lasting for decades. Sika waterproofing systems are fully tested and certified to national and international standards. This gives peace of mind to project owners, specifiers and contractors, knowing that the solutions will meet performance criteria for specific requirements.  

Sika Solutions Overview

Below-grade concrete structure basement illustration showing Sika fully-bonded waterproofing membrane in construction
Illustration of Sika bitumen and sheet membrane waterproofing on external below ground structure or water tank
Below-grade concrete structure basement illustration showing waterproofing mortars and bituminous coating
Below-grade concrete structure basement illustration showing watertight concrete application and Sika whitebox concept
Below-grade concrete structure basement illustration showing concrete repair and Sikadur Combiflex

1. Fully Bonded Sheet Membranes

Fully bonded and highly flexible TPO sheet waterproofing membrane systems can permanently prevent any lateral water migration between the waterproofing membrane and the structural concrete in the event of local damage, even when this has occurred below the base slab. Sika fully bonded sheet waterproofing membrane systems are simple and easy to use, making them fast and secure to install on site. The overlaps, butt joints and details are all connected and sealed very simply by bonding them together with sealing tapes or by welding. There are no complicated welding procedures, and no special equipment is required.

Fully Bonded, Pre-applied Polymeric Sheet Membrane

SikaProof® A+ pre-applied, fully bonded TPO membrane

Fully Bonded, Post-applied Polymeric Sheet Membrane

SikaProof® A+ adhered TPO membrane

Joint Sealing

Sika Waterbar® PVC waterstops for construction and expansion joints

SikaSwell® A hydrophilic swelling profile for construction joints

Sikadur-Combiflex® SG post-applied, bonded tapes for construction and expansion joints

 

Worker applying SikaProof® A+ basement waterproofing membrane at construction site in Qatar

2. Wet-bonded Sheet Membranes

Wet-bonded sheet waterproofing membranes consist of a cross-laminated HDPE carrier film laminated with a modified bitumen based adhesive on one or both sides. The system can be installed single or double-layered and does not require any accessories such as tapes and adhesives. The system is complemented with a fully bonded, synthetic membrane below the base slab.

Fully Bonded, Pre-applied Membrane

SikaProof®-808 pre-applied, fully bonded TPO membrane

Wet-bonded, Post-applied Membrane

SikaShield® W wet-bonded bitumen waterproofing membrane, self-protected by a cross-laminated HDPE film

Joint Sealing

Sika Waterbar® FB-125 fully bonded TPO waterstop for construction joints

Sika Waterbar® PVC waterstops for construction and expansion joints

SikaSwell® A hydrophilic swelling profile for construction joints

Sikadur-Combiflex® SG post-applied, bonded tapes for construction and expansion joints

 

Man applying wet applied bitumen membrane adhesive with trowel on below-grade wall

3. Waterproofing Mortars

Sika waterproof mortars are rigid or semi-flexible waterproofing products. They are supplied as ready to use solutions for basements to be sealed against damp soil, seepage and percolating water. They are generally post-applied externally on walls and must be used in combination with appropriate joint sealing solutions for connection, construction and movement joints. External drainage with a permanent dewatering system is also recommended, such as drainage boards.

Waterproofing Mortars

SikaTop®-107 Seal two-component, polymer-modified rigid waterproofing and protection mortar

Sikalastic®-1K single-component, polymer-modified waterproofing mortar with crack-bridging ability

Drainage Boards

SikaDrain-850 Geo

Joint Sealing

Sika Waterbar® FB-125 fully bonded TPO waterstop for construction joints

Sika Waterbar® PVC waterstops for construction and expansion joints

SikaSwell® A hydrophilic swelling profile for construction joints

Sikadur-Combiflex® SG post-applied, bonded tapes for construction and expansion joints

 

Application of cold-applied bitumen membrane with a hand trowel

4. Watertight Concrete System

The Sika Watertight Concrete System offers a comprehensive solution for watertight structures. The system consists of concrete that has been specially modified with Sika admixtures to produce waterproof concrete and carefully selected waterstops for construction and movement joints. Watertight concrete structures can be designed to keep water in or out, or both. External drainage with a permanent dewatering system is also recommended, such as drainage boards.  

Waterproofing Admixtures

SikaControl® WT-200 P crystalline powder

Joint Sealing

Sika Waterbar® FB-125 fully bonded TPO waterstop for construction joints

Sika Waterbar® PVC waterstops for construction and expansion joints

SikaSwell® A hydrophilic swelling profile for construction joints

Sikadur-Combiflex® SG post-applied, bonded tapes for construction and expansion joints

 

Drainage Boards

Sika® Drain-500 dimpled sheet

Sika waterbar water stop applied in poured concrete with rebar reinforcment construction site

5. Concrete Repair

When there is water ingress due to localized damage in the waterproofing system, the appropriate repair must be done. It shall be compatible with the waterproofing system, whether watertight concrete or lined with waterproofing mortar layer or sheet membranes.

Repair Injection

Sika® Injection-201 CE two-component PU injection resin with drinking water approval

Sika® Injection-306 three-component injection resin based on acrylate for waterproofing cracks and joints into structural concrete

Joint Sealing

Sikadur-Combiflex® SG post-applied, bonded tapes for construction and expansion joints

Waterproofing Mortars

SikaTop®-107 Seal two-component, polymer-modified rigid waterproofing and protection mortar

Sikalastic®-1K single-component, polymer-modified waterproofing mortar with crack-bridging ability

Injection for crack sealing

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