Moisture rising through concrete floors is one of the most damaging and costly problems in construction. Without effective protection, it leads to damp, rot, mould, floor covering failure, and long-term structural deterioration. This 300MU BBA-certified Polythene Damp Proof Membrane provides a robust, reliable barrier that prevents moisture transmission from the ground up.
At 300 microns thick, this membrane exceeds the minimum specification of 1200g (equivalent to 300MU) required under Building Regulations for use as a damp proof membrane beneath concrete ground floor slabs. It holds British Board of Agrément (BBA) certification — independent assurance that it performs to the required standard for moisture control in building construction.
The 4m width makes it ideal for covering large floor areas efficiently with fewer joins, reducing both installation time and the risk of moisture ingress at overlaps. At 25m per roll, each roll provides 100m² of coverage, making it a cost-effective choice for new builds, extensions, and ground floor renovation projects.
The black pigmentation provides UV resistance during outdoor storage and on-site use, helping maintain membrane integrity before the slab is poured. Joins should be lapped by a minimum of 150mm and sealed with a suitable double-sided jointing tape to ensure a fully continuous, watertight barrier.
Widely used by groundworkers, builders, and civil contractors on residential and commercial projects, this DPM meets the requirements of BS 8102 for protection of structures against water from the ground.
Size: 4m x 25m
Coverage: 100m² per roll
Thickness: 300 Microns (300MU)
Weight: 1200g/roll equivalent
Material: Polythene
Colour: Black
Certification: BBA (British Board of Agrément)
Application: Damp Proof Membrane (DPM) under concrete floors
Minimum lap: 150mm at joins
Standard: Complies with BS 8102
1. What does BBA certified mean?
BBA (British Board of Agrément) certification is an independent UK approval that confirms the product has been tested and verified to meet the performance requirements for its intended use. For a DPM, this means it has been assessed and approved for preventing moisture transmission in building construction.
2. Does this meet Building Regulations?
Yes. A 300 micron (1200g) polythene DPM meets the requirements of Approved Document C of the Building Regulations for ground floor moisture protection in England and Wales. It also complies with BS 8102.
3. How do I join two sheets together?
Sheets should be overlapped by a minimum of 150mm (6 inches) at all joints and sealed with a double-sided butyl jointing tape or DPM jointing tape to create a continuous, watertight membrane.
4. Can it be used under a screed as well as a concrete slab?
Yes — this membrane can be used as a DPM under both concrete floor slabs and sand/cement screeds. Ensure it is fully lapped and taped at all joins and upstands to walls.
5. How much coverage do I get per roll?
Each roll is 4m wide x 25m long, providing 100m² of coverage. Account for laps and upstands at walls when calculating how many rolls you need.
All our products are dispatched from the United Kingdom, with most items arriving within 3-5 working days. For custom-made or made-to-order items, delivery times may vary, and any exceptions will be clearly indicated during the checkout process.
