Skip to content
British Standard Recommendations
One of the primary recommendations of BS 8102:2022 is that with any basement, at some point in its life you should expect that water pressure will come to bear against it. Although the timing of such an event cannot be predicted, this is a practical and sensible recommendation that takes into account the unpredictability of future rainfall, changes in watercourses, or even possible burst water mains in the surrounding area. In our view, it is a very brave person that bets that water will never come to bear against a basement at some point in its existence.
Not only is it not possible to predict the timing of such an event, it is also impossible to determine the amount of water pressure that will come to bear against the basement. The British Standard helps us out once again here by recommending that, in almost all cases, the designer should expect and cater for a full head of hydrostatic water pressure. In other words, that at some point the ground surrounding the basement will be saturated so that water will come to bear against the full height of the basement.
‘Type C’ Cavity Drain Waterproofing Explained
Amongst the three different types of waterproofing available to the designer, BS 8102:2022 defines ‘Type C’ waterproofing as “drained protection” that works by receiving leaking water into voids and spaces created by strategically positioned drainage channels and cavity drain membranes installed to the internal walls and floor of the basement. The clever design of a cavity drain system means that ingressing water is depressurised as it enters these voids before being safely removed from the property.
Because Type C waterproofing is maintainable and considered to be the safest and most reliable form of basement waterproofing, it is very often the choice of the professional waterproofing contractor and is nearly always one of the systems chosen where combination waterproofing is used to both existing and new basement structures.
A maintainable Type C solution, based on decades of basement waterproofing experience, comprises a range of high-quality, BBA certified cavity drain membranes and bespoke pumping systems which include battery backup systems and telemetry options. Over the years, such systems have been used to safely turn hundreds of wet and damp basements into dry, habitable environments.
Understanding BS 8102:2022 Recommendations for Basement Waterproofing
The Challenge of Water Pressure in Basements
One of the primary recommendations of BS 8102:2022 is the expectation that, at some point in its life, a basement will experience water pressure. Although the timing of such an event cannot be predicted, this is a practical and sensible recommendation considering the unpredictability of future rainfall, changes in watercourses, or potential burst water mains in the surrounding area. Betting that water will never come to bear against a basement is a very brave, and perhaps risky, assumption.
Not only is it impossible to predict when water pressure might impact a basement, but it is also impossible to determine the amount of water pressure that will arise. The British Standard advises that, in almost all cases, the designer should expect and plan for a full head of hydrostatic water pressure. This means that, at some point, the ground surrounding the basement will be saturated, resulting in water pressing against the full height of the basement.
Protecting Against Water Pressure
So, how do you protect against such a scenario? Among the three different types of waterproofing available, BS 8102:2022 defines ‘Type C’ waterproofing as “drained protection.” This method works by receiving leaking water into voids and spaces created by strategically positioned drainage channels and cavity drain membranes installed on the internal walls and floor of the basement. The clever design of a cavity drain system means that ingressing water is depressurised as it enters these voids before being safely removed from the property.
Type C Cavity Drain Waterproofing Explained
Type C waterproofing is maintainable and considered to be the safest and most reliable form of basement waterproofing. It is often the choice of professional waterproofing contractors and is almost always one of the systems chosen where combination waterproofing is used for both existing and new basement structures.
A high-quality Type C solution typically comprises a range of BBA-certified cavity drain membranes coupled with bespoke pumping systems, including battery backup systems and telemetry options. These systems have been used to safely turn hundreds of wet and damp basements into dry, habitable environments.
Conclusion
Expecting and preparing for water pressure in basements is a practical approach recommended by BS 8102:2022. By adopting Type C cavity drain waterproofing, designers and contractors can ensure the long-term protection and reliability of basement structures, transforming them into safe, dry, and habitable spaces.