Wet Basements / Cellars – Basement Waterproofing throughout London
Being below ground, basements and cellars are susceptible to ground water being forced into the structure under pressure. Factors such as type of structure, depth of structure, makeup of surrounding soil and location of the structure all play a part in how much dampness or water ingress is experienced by the basement or cellar during the course of its lifetime. The types and levels of basement waterproofing are just as numerous as the causes of dampness and it is essential that all factors are taken into consideration when designing the waterproofing system.
Commonly referred to as either basement tanking or structural waterproofing, a systematic and thorough approach is needed at design stage to ensure that all remedial works not only adhere to British Standards (BS8102:2009) but achieve the intended results.
Type A Waterproofing
Type A basement waterproofing also known as tanking, it is an externally or internally applied barrier system applied to the walls and floors of the structure that can withstand ground water from entering the building under pressure. There are numerous products and methods for applying Type A waterproofing systems including sheet membranes, multi-coat renders, crystalline slurries and bitumen based coatings. A thorough assessment of the structure must be carefully assessed at design stage to ensure its suitability. This system requires the structural elements of the building to be strong enough to withstand ground water pressure.
Type B Waterproofing
Type B waterproofing is an inbuilt characteristic of the actual structure by adding waterproofing additives to the concrete used to form the floors and walls of the structure. Although normally effective in its own right, the joints of the structure are it’s weak spot and as such are susceptible to water penetration. Type B waterproofing is normally backed up by combining type A, C or sometimes both to ensure a watertight system and minimise risk. Type B basement waterproofing is normally specified in newbuild below ground structures.
Type C Waterproofing
Type C waterproofing is essentially a set of dimpled membranes called Cavity Drain Membrane (CDM) installed externally or internally to the walls and floors of the basement structure. A type C basement waterproofing system does not aim to prevent the incoming water to the structure but instead manages it and diverts it into either a pumping chamber or external land drain. This system is suitable for all structure types and is quickly becoming the preferred system for existing cellars and basements that are subject to ground water ingress due to its relatively low risk of defect and ease of installation.
To book a site survey, consultation and no obligation quotation on our cellar/basement waterproofing services throughout London, please use our online contact form or call us on: 020 8959 6424.