New Build Basement Waterproofing
Stronghold Preservation provides a basement waterproofing design
service in accordance with BS 8102:2009.
BS 8102 recommends that a specialist basement waterproofing
contractor be included in the design team at an early stage in the
design process. From our experience, early inclusion in the
design is the most successful and cost effective; and is the most
likely way for the client to achieve their goal without
compromise.
We at Stronghold Preservation provide a 10 year insurance backed
guarantee for all basement waterproofing where we have provided the
design detail, and installed the basement waterproofing system.
There are a number of basement waterproofing systems on the
market; we have chosen to be accredited to those systems which we
believe offer the best, problem free solution to providing a dry
basement for your new build home or building. All our
surveyors and operatives are fully trained in basement
waterproofing.
The optimum basement waterproofing system is dependent on the
quality of the basement required. Basements are classified
into 4 grades:
- Carparks & non-electrical plant rooms - some seepage and
damp
- Plant rooms, workshops & retail storage - no damp, but
moist environment
- Habitable rooms; residential, offices etc - dry environment
required
- Controlled environment; museums, etc - controlled, totally dry
environment
Cavity Drain Basement Waterproofing Systems
The retaining wall in the cavity drain basement
waterproofing system should be built as per the engineers
specifications, and should provide some resistance to water
seepage. Insitu concrete provides more resistance to water
penetration than masonry, and is therefore the preferred
construction method. A drain is installed at the base of the
retaining wall, and a dimpled basement waterproof membrane
mechanically fixed to the retaining wall. Any water which
does seep through the retaining wall is depressurised, and drips
into the cavity drain. The water is then removed from the
drain by a sump and a pump, or through an open elevation, into the
storm drainage. This waterproofing system is a water
management system, which deals with the water which may seep
through the retaining wall, giving an extra layer of
protection.
Basement Waterproof Barrier Systems
The structure relies on a waterproof internal or external
membrane to prevent water ingress into the internal basement
environment; eg bonded sheet membranes, cementitious tanking, bentonite
matting. This system relies on holding back the water, and requires
the workmanship to be 100% defect free. Any defects in the
barrier will allow water to seep into your basement or cellar.
Integral Basement Waterproofing
The basement waterproofing is designed into the retaining walls,
through the use of waterproof concrete, or similar, and is most
commonly used in underground car parks, swimming pools and lift
pits. The concrete will have additional mesh or reinforcing
within it to try and prevent cracking (which would allow water
ingress), as well as waterbars at joints, which will swell on
contact with water, preventing water seeping any further.
Combined Basement Waterproofing Systems
A combined basement waterproofing system is required where the
likelihood of water ingress is high, the consequences of leakages
is unacceptable, or where unacceptable water vapour could
occur. A combined system uses two or more of the above
waterproofing systems, combined; for example, a barrier system in
conjunction with the cavity drain system, and therefore gives the
best possible protection to your basement.
BS 8102:2009
BS8102 is a design document which informs the designer on
basement waterproofing and assists in the correct specification of
those systems. It states that for a basement waterproofing
system to be successful it must deal with groundwater, soil gases
and contaminants and that these should be considered from early
planning and design stage; a specialist waterproofing company is to
be included in the design team from an early stage, so that the
waterproofing design is an integral part of the design process.
The general principle of BS8102 is to select a basement
waterproofing system capable of providing the required internal
environment, by reducing the risk of water reaching the internal
environment. However, it notes that workmanship and materials
cannot be 100% defect free, and requests that a contingency plan is
put into place to manage any water that bridges the retaining wall,
as a secondary measure to prevent water entering the internal
environment.