The importance of using a CSSW qualified professional in structural waterproofing projects

It is not only the required criteria for many specialist buildings insurance companies such as Premier Guarantee, LABC, BLP and the NHBC to mention a few nowadays that a CSSW qualified person is involved in the design process for structural waterproofing, which in turn reduces risk of catastrophic failure, but it is also now more generally accepted to be just common sense by any astute construction companies and building professionals.

This includes the design and build type of companies who usually value good sound advice for what is often the most critical aspect of a construction project, most notably with their design P.I., reputations and responsibilities firmly in mind, and perhaps more importantly as well as below ground level applications, for tunnels, podiums and decks over basements, green roofs or Buried roofs, or anywhere within a structure where water ingress would have a negative impact on the structures performance specifications, as it is widely recognised that poor waterproofing design will almost always result in failure, and expensive ones at that, especially in the higher ends of the construction markets too.

It is also a strong recommendation within BS8102:2009 guidelines that suitably qualified persons are involved from inception stages to the likes of the above mentioned projects, and ideally the candidate will have relevant experience of all three of the main types of waterproofing systems, known as:

• Type-A (barrier protection)
• Type-B (Structurally Integral watertight construction)
• Type-C (Cavity drained protection)

They should also be able to offer guidance to the design teams they work with in relation to differing ground conditions, water table levels, soil hydrology, ground types, ground drainage characteristics and potential contaminants such as ground gasses and soil contaminate, hydrocarbons, Methane and Radon gas to mention a few.

In addition identifying differing types and forms of construction from steel sheet piles, contiguous and secant piles, reinforced concrete structures, insulated concrete formwork and masonry or combinations of these.

They should also be aware of the relevant grades of waterproofing for a given project, or particular areas therein also recognised under BS8102:2009.

Table 2 from BS8102:2009

• Grade-1, can be underground car parks / plant rooms, (excluding plant rooms with moisture sensitive equipment within them),
• Grade-2, workshops / storage and plant rooms requiring drier environments than a grade-1,
• Grade-3, which is for commercial, domestic, archives / museums / libraries etc, which will often also require mechanical aids and controls, such as ventilation / extraction / air conditioning etc, usually due to a lack of natural ventilation so as to be better able to achieve their relevant ambient temperatures and humidification levels.

Although the environmental control elements will mostly be outside of the CSSW qualified persons remit, without actually being informed of what the underground area is to be used for, they could not realistically provide the performance or BS8102:2009 specification guidelines and relevant guidance without proper training and knowing the former and other important points mentioned here.

The CSSW qualified person could be an independent consultant, an employee of a relevant materials supplier or manufacturer, or work for a specialist waterproofing contractor, but the main thing being to ensure that they are involved with the design team from inception stages, which will dramatically reduce risk for all parties.

It’s not good news when a qualified individual has to break the bad news that a waterproofing failure was down to poor design, especially when the systems were also installed by un-specialised or inadequately trained contractors too. A CSSW professional can usually recommend appropriate specialist installers for you too.

Delta membrane Systems Ltd are also now offering the CSSW syllabus and training modules, but spaces are limited, so if this is something which you believe will add to your skills and make you stand out from the crowd, or enhance your opportunities within such a specialist field then please do not hesitate to contact us.