PermaSEAL 7 Terrain Drain Membrane 40m²

Diagonal Stud External Waterproofing Membrane

PermaSEAL 7 Terrain Drain is an external cavity drain membrane for waterproofing new basements and below-ground structures. It features a unique 7mm diagonal stud formation and an integrated filter fabric layer to prevent fines and sediments entering the cavity.

It should be installed along with a French drain or Land Drain to alleviate hydrostatic water pressure on the structure.

Important note: Terrain Drain Membranes need to be used in conjunction with a fully bonded primary waterproofing system.

Terrain Drain Membrane Installation

The PermaSEAL 7 Terrain Drain Membrane is an essential part of an external waterproofing system. For help with specifying a suitable system, speak to our technical team on 0117 982 3282.

Installing the Terrain Drain membrane is straightforward as part of new basement construction. Read our guide to external waterproofing for more details.

• External walls should be waterproofed with a fully bonded waterproofing system. We recommend PermaSEAL PRO MP 2C Waterproofing prior to the installation of the optional insulation layer, then the PermaSEAL 7 Terrain Drain membrane.
• A fillet should be formed where the basement wall meets the footing with PermaSEAL Fillet Seal.
• PermaSEAL 7 Terrain Drain should only be fixed at ground level in the top row of studs at 250mm centres.
• Place the land drain a minimum of 200mm below basement floor level.
• PermaSEAL Geodrain Capping Strip should be used to achieve a neat finish.
• Use perforated pipe for the land drain or French drain surrounded in 20mm clean-graded aggregates.
• Protect the Terrain Drain membrane with a backfill protection board when mechanically backfilling.
• Use a well-drained backfill, and protect the backfill with Geotextile filter fabric.
• Where possible you should slope the ground away from the retaining wall or ensure efficient drainage.

PermaSEAL - Complete solutions. Made possible.

If you want technical advice on structural waterproofing and how to use external waterproofing membranes, then contact our experts today. Our technical advisers are available on 0117 982 3282.

Return to the external waterproofing category to browse more products.