When waterproofing a below ground structure with a Type C cavity membrane system, a suitable
basement drainage system is also required to safely remove ground water ingress which percolates
This drainage system is made up of four key components - a submersible pump, often referred to
as a sump pump, basement drainage channels/modular drainage system, high level water alarm(s)
and battery backup(s), larger projects may also require a control panel.
A sump pump (submersible pump) solution will require mains power to operate. No matter which
types of sump pump system you have installed, it may at some point fail because of a power outage.
Our extensive range of battery back-ups offer unrivalled technology and will keep sump pumps
working in the event of power failure. The number of pump systems required for each project will (in
part) depend on the overall basement size, perimeter, and the method of drainage – Delta Channel,
Modular or a combination of both. External surface water from light-wells, courtyards and terraces
may be drained into the ground water sump, providing the area of external surface water collection
does not exceed 12m² to each sump – if the external area is greater, advice should be sought from
the Delta Technical Team.
Both perimeter drainage channels and modular drainage will efficiently disperse any water ingress
which percolates the structure to a sump chamber. The sump chamber will collect and manage
any water ingress which is collected in the cavity drainage system and then safely evacuate this to a
suitable discharge point. This is referred to as a sump pump system. A sump pump system protects
a property against flooding.
For each sump system, the recommendation is for two pumps in case of failure of the duty pump. In
the event of failure of the duty pump, the secondary back up pump will take over, therefore significantly
reducing the risk of potential flooding.
In addition, a minimum industry standard would be to include a high-water level alarm such as the
Delta AlertMaxx2 EC or HLA and power back up system such as Delta PowerMaxx2, Hi-PowerMaxx2
or Hi-PowerMaxx2 XL in case of mains power failure. Reducing the risk of potential flooding to a
Battery Backup systems are an integral part of the whole Type C, Cavity Drain Waterproofing System
and a second line of defence for the basement drainage system.