• 30 November 2018

Basement Waterproofing: An Art in Protection

While many people in the construction industry associate us with just tunnelling, it isn’t the only sector that we are experienced in. At first glance, basements aren’t similar to tunnels in shape, scope, dimension or even use, but when water is involved, the consequences are very similar indeed.

As civil engineers, we have seen the issues caused by poorly constructed basements in residential settings first-hand and believe that it is a problem that needs to be dealt with sooner rather than later.

Traditionally, basements haven’t been built far below the water table which means there hasn’t been a great need for serious waterproofing over the past century. However, as Singapore’s population grew, the industry has definitely shifted.

Basements are now built deeper and deeper and are constructed closer to harbours, bays and rivers. As such, waterproofing has never been more important to homeowners, builders and engineers during the design and building phases.

Lack of experience linked to issues

While builders and civil engineers operate in similar industries, their roles couldn’t be further apart. A builder does everything from the ground up, highly experienced in many trades, while civil engineers will probably be found working on bridges, airports, highways and most underground applications.

Most builders are well versed in waterproofing roofs, balconies, bathrooms and buildings, but when it comes to waterproofing underground, the same level of knowledge and experience isn’t always there to attempt such a job.

Waterproofing underground is a vastly different environment to anything found above ground and many underestimate how difficult it is. The techniques used to waterproof roofs generally are not robust enough to resist high levels of water pressure. Most people would agree that a waterproof roof is unlikely to remain sealed under 5m of water pressure.

Basements sometimes need to resist 10-20m of water pressure which obviously requires an entirely different approach. Since there are no standards for underground waterproofing, commercial builders can look for support from anywhere. Many, in fact, talk to their local material suppliers who commonly don’t have the expertise to guide builders to the right techniques or materials to undertake these operations safely.

More industry collaboration required

As basement waterproofing jobs increase and the consequences are highlighted in the media, I believe that there needs to be greater collaboration between civil engineers and the building community. From my perspective, we have strong specific experience in ground water management, waterproofing, drainage and filtration, but aren’t generally called on in a residential setting because builders don’t know about how we can help.

Companies like us have been sealing against water pressures of up to 80 metres below the water table. As such, our industry can seal concrete structures in some of the toughest underwater environments, yet many builders struggle against as little as three metres of water head.

This disconnect between builders and civil engineering providers needs to be bridged. Businesses like us don’t want to compete with the small businesses working on residential buildings, instead we can act as a source of quality materials, provide industry-standard experience and ensure that the asset owner receives a basement that is able to prevent leakage or future water damage. This is beneficial for not only the durability of the structure but also their overall health and wellbeing.

How can this be achieved?

Basement waterproofing will be a challenge that will probably last beyond my generation without civil engineering companies and builders working more in tandem. We, for example, has significant experience working with Singapore civil engineering companies that are experts in underground operations. Our International experience and industry network allows us to keep abreast of latest development in Standards and Specifications for this type of work.

These connections have improved tunnelling infrastructure dramatically in the recent past, but now it is time for the residential basement waterproofing standards to rise as well.