Two waterproofing solutions for underground drainage

A proven waterproof solution is essential for safeguarding basements, car parks, tunnels and other belowground concrete structures against damp and water ingress. But which system is best suited to your building? A render-based product? A drainage system incorporating a membrane? Sika offers both solutions as part of its proven, wide-ranging concrete and waterproofing range, so let's examine the benefits of each.

Sika^®-1 Pre-Bagged waterproofing system comprises watertight renders and screeds produced using the Sika^®-1 Waterproofing Liquid and Sika^®-1 Pre-Batched Mortars. The mortars consist of a blend of special cement and kiln dried graded aggregates. Packaged in four grades, each is specifically designed for optimum application performance and durability.

Key considerations when specifying Sika^®-1 Pre-Bagged:

• Once applied, it requires absolutely no maintenance
• It is more cost-effective when applied to areas of 300m² or less
• The render system takes up minimal space
• Bonds directly to the substrate – follows the contours of any structure
• Withstands high water pressure
• Substrate preparation may be required

 In terms of a water management solution, Sika^® CD-Cavity Drain System uses a high density polyethylene internal drainage membrane to control water after it has penetrated a structure. The system is installed, loose-laid in flooring applications and attached to the wall with surface plugs in vertical installations. The system directs penetrating water into a drainage system and a collection sump before using a pump to discharge water from the building. A cavity drain provides protection from the ingress of water, vapour and gases.

Key considerations when specifying Sika^® CD-Cavity Drain System:

• System requires ongoing maintenance and running costs
• Requires more space to install
• Acts as a vapour barrier
• Limited surface preparation required
• Can be used where the substrate does not have the strength to resist stresses caused by water pressure
• Most cost-effective on areas larger than 300m²

 Although varying in application and comprising different materials, the systems share common properties. For instance, Sika^®-1 Pre-Bagged and Cavity Drain are suitable for new-build and refurbishment projects involving a range of belowground structures.

As well as being BBA-approved, both systems carry a Sika guarantee when installed by an approved contractor. Other common properties include the systems' suitability for use to grades 1-3 according to BS 8102-2009, and high water table according to BS 8102-2009.

What then, must we conclude from this comparison? Well, by eliminating the need for ongoing maintenance, the Sika^®-1 Pre-Bagged system is a more cost-effective solution over a lifespan of 60 years, particularly for structures 300m² and below.

Not as simple to apply as the pre-bagged system, on account of its additional components, Sika^® CD-Cavity Drain System is a more ideal waterproofing solution for areas larger than 300m². Ongoing running costs are incurred, as the system requires regular maintenance.

Sika^®-1 Pre-Bagged or Sika^® CD-Cavity Drain system…whichever system you choose as your belowground solution, you are guaranteed the same quality: superb, long-term waterproof performance.

• Sika operates a Registered Contractors scheme, designed to help facilitate the selection of suitable contractors to install Sika waterproofing systems including Sika^®-1 and Cavity Drain. Choosing a Sika Registered Contractor provides total quality control – from product to service and installation – giving clients added reassurance that they will receive the highest standards of professionalism at every stage.

Visit: https://www.sikawaterproofing.co.uk/products-systems/sika-cd-cavity-drainage-system/