The Damp Proof Membrane 300mu Black 4m x 25m is a high-quality, heavy-duty polyethylene sheet used to prevent moisture intrusion into structures. With a thickness of 300 micrometres, it serves as an effective barrier against dampness from the ground, providing protection for building foundations, retaining walls, and other structures. Its robust design ensures its durability, offering long-term damp proofing solutions for various construction and DIY projects.