BS8102:2009 & Basement Waterproofing
BS8102:2009 is the Code of practice for protection of below ground structures against water from the ground. This document provides a set of guidelines that should be followed when designing a waterproofing system for any below ground structure, including basements, vaults, cellars and car parks.
Whether your project is a new build, renovation of an existing property or you simply want to ensure your basement is dry enough to use for additional storage, the design philosophy of BS8102 should be applied. One important point made in this document is in paragraph 4.2, where it states “A waterproofing specialist should be included as part of the design team so that an integrated waterproofing solution is created”. A waterproofing specialist will hold a CSSW qualification, (Certificated Surveyor in Structural Waterproofing) as proof of their expertise. It is important that any basement waterproofing project has a CSSW involved to ensure the system is designed and installed correctly.
Design Philosophy of BS8102:2009
This code of practice includes a design process that should be applied when it comes to designing a suitable basement waterproofing system. For new developments, information such as soil reports, method of construction, nearby watercourses and the water table classification should be taken into account.
The waterproofing designer should also consider what defects may occur with the selected system and how the system can be maintained or accessed for remedial treatment if necessary.
For new builds, often two forms of waterproofing will be required by the warranty provider and in some cases this will may apply to renovation projects too. It is important to check this at the design stage so these can be included with the design.
Different Types of Waterproofing
There are three common types of waterproofing system defined in BS8102:2009.
- Type A – Barrier system that can be applied internally or externally. The products used can include cementitious renders, bentonite clay membrane, bonded sheet membranes or liquid applied tanking membranes
- Type B – Structurally integral protection, typically the use of waterproof concrete to form the structure.
- Type C – Drained protection, this consists of a drained cavity typically installed with a sump pump system to discharge ground water.
Table 1 in BS8102:2009 gives us guidance as to what types of waterproofing system are suitable for different water table classifications: