External ground damp proof membranes, fitted before water becomes a problem.
Installed to the perimeter of newly constructed basements, or where ground levels are lowered around an existing one, complete with suitable drainage — stopping water before it enters the wall structure.
Bensleys can install external damp proof membrane systems, complete with suitable drainage, to the perimeter of the building on newly constructed basements, or where ground levels are lowered to the perimeter of an existing basement. These membrane systems will stop water before it enters the wall structure at all.
Why Go External
Because the membrane sits outside the wall, water is intercepted before it can affect the structure or the internal finish — often meaning less internal disruption than a system installed from inside, and no compromise to internal floor-to-ceiling height.
New Build
Newly constructed basements
Applied to the perimeter during construction, before backfilling, giving the most straightforward access for a thorough installation.
Retrofit
Lowered ground levels
Where ground levels around an existing basement are lowered, the newly exposed wall face can be fitted with an external membrane.
Drainage
Perimeter drainage included
Suitable drainage is installed alongside the membrane, carrying intercepted water away from the structure entirely.
How we install it
From excavation to a protected perimeter.
Access & excavation
For new build, this happens before backfilling; for existing basements, ground levels are lowered to expose the wall face.
Membrane installation
The external membrane is applied to the exposed wall face, forming a continuous barrier against ground water.
Perimeter drainage
Suitable drainage is installed alongside the membrane to carry intercepted water away from the building.
Backfill & reinstatement
Ground is reinstated around the protected wall, completing the installation.
Related systems
Other basement waterproofing options
Each has its place, and the right choice depends on wall construction, water pressure, and whether the space needs a sump and pump. Each system below has its own dedicated page.
Cementitious Tanking Membranes
A modified cement slurry or multi-coat render applied directly to the internal face, stopping moisture at the point of entry…
Find out moreCavity Drain Membranes
A dimpled cavity membrane creates a drainage cavity behind the wall, collecting ingressing water and channelling it away — with…
Find out moreFrequently Asked Questions
Find clear answers for External Ground Damp Proof Membrane.
What is an external ground damp proof membrane?
When is an external membrane used rather than an internal system?
Does this system need internal finishing work afterwards?
Can this be combined with an internal system?
New build or lowering ground levels? Let's talk external membranes.
Get in touch early in the project so external waterproofing can be planned in from the start.