National housing shortages and high land costs are pushing developers towards building houses that demand the highest levels of expertise in waterproofing design, ensuring proper protection from water ingress. However, there are concerns that these high demands are not being met in some of these new developments. Nik Ullfors, National Technical Manager from Visqueen discusses why housebuilders need to take waterproofing design seriously and how they can avoid the severe consequences of incorrectly implemented waterproofing.
184,000 homes were built in England in 2017 – the highest number since 2008 as part of efforts to tackle the acute housing shortage the UK faces. The high costs and shortage of land is driving developers to build on difficult areas such as flood plain, or locations which require retaining walls or embankments, with around 10,000 new homes constructed on land with a significant chance of flooding each year.
All of these environments require properties to be properly protected against water ingress from rainwater or groundwater. Combine this with the UK’s famously wet weather and changes in climate and the importance of correct waterproofing becomes evident.
What is at stake is not just the potentially life-changing impact ineffective protection can have on houses and the families that live in them but also the liability and potentially overwhelming remedial and legal costs that housebuilders could incur should waterproofing measures be installed incorrectly.
The Costs of Water Damage
Anyone who has been unfortunate enough to suffer from water ingress into their home will know how devastating it can be. Families can be forced out of their homes for months or even years whilst work is carried out to repair structural damage and personal effects can be lost forever.
Costs, without proper insurance, can fall on the occupants or businesses themselves which can be unaffordable for many.
Developers Under Pressure
Housebuilders and architects face constant pressure to keep costs within budget. Exacerbating this is the push for more affordable houses to be built which naturally puts a squeeze on the development’s margins. Waterproofing can sometimes therefore be a low priority in a new build and be vulnerable to any cost-cutting drive, leaving some to do it ‘on-the-cheap’.
Cutting corners in waterproofing however is a false economy – whatever the cost pressures. This is because the designer of a building is ultimately legally liable should a fault in the design result in damage to the building, opening the potential of costly legal action and the possibility of having to fund remedial works.
Waterproofing is a specialist sector as it requires in depth knowledge of relevant building regulations, how sources of water move through soil, geotechnical experience and understanding of soil reports. This expertise is especially important when it comes to underground structures such as full basements or partial basements and the sector sees dedicated contractors, architects and manufacturers all specialising in waterproofing. It is these specialists who can ensure that waterproofing design, implementation and legal liability are carried out correctly.
How Ensure Correct Practise
The source of many waterproofing problems can often stem from improper design. Traditionally it has been the role of the architects to draw up and recommend the waterproofing design for a project, however the vast majority of architects will readily acknowledge that they do not have the training or expertise to undertake this specialist function. In fact, the only reason some have been doing it is because there are so few people in the industry who are willing to undertake this role!
The right knowledge, practical experience and expertise is therefore crucial to the success of a waterproofing design. However, identifying suitable specialist and specialist companies that have the appropriate design capability and resources from those who don’t can be challenging. Even the most experienced design teams and building developers can struggle to single out appropriate waterproofing design guidance.
Under waterproofing guidance BS8102:2009 it is recommended that, once the design team has given the system initial thought, an appropriate specialist should be contacted immediately for early advice and help on the waterproofing design. This is set out in section 4.2 of BS8102:2009 which states: “A waterproofing specialist should be included as part of the design team so that an integrated waterproofing solution is created”.
Sealing Success
The best way to secure this required level of expertise is to use the services of a Certificated Structural Surveyor in Waterproofing (CSSW). These professionals are part of a technical team and specialists in waterproofing matters, providing technical support on geology, topography, engineering and geographical rainfall issues these are all required by the designer in accordance with BS8102:2009. Importantly, they are also protected by Professional Indemnity Insurance which provides the necessary backing to housebuilders from any costly liability proceedings.
CSSW designs, which can be provided as part of a waterproofing manufacturer’s services, will help ensure that initial outline proposals are compliant and can also advise on how other structural elements interact with waterproofing measures, and if extra protection methods are required to prevent damage by further construction. They are also covered by professional indemnity insurance which provides architects or designers with protection from waterproofing claims as the design ownership lies with the CSSW trained specialist designer.
As housebuilders and developers continue adapting to modern pressures it is vital to not chase short-term cost benefits by ignoring proper waterproofing design. Getting the experts in gives each project the waterproofing solution it demands and provides the necessary ownership and insurance cover.