Exterior Waterproofing - Cavity Drain Membrane
PermaSEAL 8 Geodrain is a twin sheet 8mm stud cavity drain membrane with Geotex, a filter fabric, thermally welded to the studded face. It is used externally below ground in conjunction with a land drain or French drain and a bitumen waterproofing material.
The filter fabric allows water to pass into the cavity created by the 8mm studs but will not allow fines or sediments to pass into the cavity. Any water entering the cavity immediately de-pressurises and falls down to the perforated pipe (land drain or French drain) which is situated below floor level which in turn drains the water away to a suitable drainage point. The filter fabric should continue around the perforated pipe to also protect it from fines and sediments.
PermaSEAL 8 Geodrain Installation Diagram:
PermaSEAL 8 Geodrain Installation Advice:
- A fillet should be formed where the basement wall meets the footing.
- External walls should be damp-proofed with a paint on bitumen based product (Sulfiton Profi-Tight) prior to installation of the Geodrain.
- PermaSEAL 8 Geodrain should be fixed in the top row of studs at 250mm centres.
- Place footing drain 200mm below basement floor level.
- For a neat finish PermaSEAL Geodrain Capping Strip should be used to cap the top of the membrane at ground level.
- Use perforated pipe for the land drain or french drain.
- Protect the PermaSEAL Geodrain with backfill protection board.
- Use a well drained backfill, and protect the backfill with Geotex filter fabric.
- Slope ground away from retaining wall where possible or drain well.
- PermaSEAL Geodrain should always be used in conjunction with a land drain or french drain connected to efficient outlets to remove drained water
- Resistant to all chemicals normally found in the ground
- Withstands stresses and movement acting as a slip membrane as the backfill settles
- Prevents water pressure from bearing against the structure
- Extremely strong material, minimising the risk of damage when backfilling even when no protection board is used
- High compressive strength (250kN/m²)
- Suspended soil particles are filtered out by the geotextile layer
- Quick and easy to install with a range of ancillary fixing and installation products
Model: PS8GD40 SKU PS8GD40 Manufacturer: Permagard Packaging: individually Size: 2m x 20m x 8mm (studs) Coverage: 40m² Country of Manufacture: United Kingdom
PermaSEAL Geodrain Data Sheet (650.1 KB)