March 2006

How can you eliminate the risk associated with waterproofing today’s structures?

High performance ‘Colour Coded’, seamless and fully bonded waterproofing systems provide many of the answers. Applying two coats of a contrasting colour provides the installer with an in-built quality control mechanism in the form of visual inspections. The first coat should not be visible through the second coat. If it is, the membrane remains incomplete. So, what else should influence the selection of a waterproofing system?

Attributes & Limitations
A specifier needs to understand the ‘attributes’ of the waterproofing system being considered to ensure that it is fit for purpose, and as with most manufacturers, RIW are more than happy to advise on what the product can do. However, RIW also appreciate it is more important to understand the proposed products’ ‘limitations’. The risk of waterproofing failure will increase without a good understanding of (i) what the product can’t do, (ii) the simplicity of detailing at critical areas (iii) the impact of prevailing site conditions on the product & (iv) the impact of workmanship.

Simplicity of Detailing
With a good understanding of how waterproofing systems will perform you should now consider its suitability for your specific project. Generally, most waterproofing systems are simple to install on uncomplicated substrates. However, the detailing of the same system can become overly complicated at the most critical high risk or vulnerable areas – such as complicated/irregular profiles, around service penetrations, construction and movement joints. For instance, using a liquid applied system around penetrations and irregular profiles will allow the membrane to follow the contours it is applied too. A preformed sheet or single ply membrane applied to the same detail could become over complicated to install in these critical areas, thus increasing the risk of water ingress.

Product Compatibility
A waterproofing strategy will generally include more than one product. Therefore, it is important to ensure the compatibility of a product where it interfaces with another. Whilst generic products may appear to be the same, the chemistry of modern & traditional membranes will differ between manufacturers. This incompatibility can be overcome by using waterproofing systems from one manufacturer, however, this is not always possible and all leading manufacturers will be able to confirm the compatibility or advise accordingly. Occasionally, other products are proposed as alternatives to the original specification – these systems may not be suitable (Attributes & Limitations) or compatible with the other specified products. In essence, once a specification has been written, no alternations should be made or allowed to the specification, the design or installation sequence without the involvement of the designer, specification writer or relevant manufacturer.

Seek Professional Advice
Leading manufacturers of high performance waterproofing systems offer professional and reliable waterproofing design advisory services with field and office based Technical Advisors who are willing to provide advice and guidance including preparation of section details, method statements, NBS clauses, site inspections and ongoing site support. It makes sense to eliminate risk by discussing your requirements with a company such as RIW which specialises in waterproofing and has over 80 years experience of developing waterproofing strategies.

Therefore, the golden rules when designing your waterproofing strategy are:

1. Understand the Limitations as well as the Attributes of the waterproofing systems
2. Keep the waterproof as simple as possible in vulnerable or critical areas
3. Ensure that all elements of the waterproofing strategy are compatible with each other
4. Seek advice from the Technical Department of a leading manufacturer at an early stage of the design process.

Further information about RIW Flexiseal is available by contacting technical@riw.co.uk