As outlined within British Standard BS 8102, there are four
grades of basement dryness:
Grade 4 is a completely dry environment suitable for the storage
of archives & antique storage.
Grades 3 and 2 are suitable for habitable areas such as office
and domestic uses.
Grade 1 is suitable for more industrial areas for example plant
rooms & garages where minor moisture ingress is acceptable.
Aquarend are qualified and certifed installers of the industry’s main
manufacturers of Cavity membrane systems, including:
Delta Membranes – Delta Membrane Product PDF Page
Sika Ltd – Sika Cavity Drainage System PDF
Triton – Triton Chemicals – Cavity Drainage System
Newton Membrane –
Oldroyd – Cavity Membranes
Water damage to underground structures is a often a debatable
issue with several differing views about which is the best method to treat the
problem. With over 25 years of expertise, Aquarend understands that the optimum
remedy will depend on a multitude of factors such as the age of the building
for existing buildings only, proximity to water courses, level of waterborne
contaminants, overall condition of the existing structure, future use of the
area and basic nature of the water ingress. 
An Aquarend diagnostic survey will identify the prevailing
factors and the recommended remedy will also depend on the intended use of the
basement, and a cavity drainage system using a studded membrane and a pump to
drain the water may be preferable to using a cementitious tanking approach.
Cavity drain membranes work on a very simple principal; they
allow water and moisture to carry on penetrating the structure but control it within
the air gap between the membrane and the building, diverting it to a suitable
drainage point or pump if required.
Correctly installed and maintained cavity membrane systems do
not allow water pressure to build up against the internal construction with the
air gap behind the membrane allows the structure to ‘breathe’. 
The membranes are impermeable to water, and gas and vapours
and therefore protect the internal space from dampness and gaseous exposure. Cavity
Membranes are loose laid on floors and fixed to walls using unique plugs and
sealing materials.
Cavity membranes can be fitted with little or no preparation
to the substrate and once installed, wall surfaces can be dry lined or
plastered directly, with floors screeded, or a dry boarded.
This method of basement waterproofing allows decoration and
floor finishes to be completed almost immediately, without the drying out
periods required for cementitious renders and tanking.
Please bear in mind that should a sump/pump system be installed it is recommended
that the system be inspected and maintained on a biannual basis to ensure any water
ingress collected by the system is being diverted away correctly.
