Sewer gas Sewer gas Sewer gas is a complex mixture of toxic and nontoxic gases produced and collected in sewage systems by the decomposition of organic household or industrial wastes, typical components of sewage. Sewer gases may include hydrogen sulfide, ammonia, methane, esters, carbon monoxide, sulfur dioxide and nitrogen oxides. Improper disposal of petroleum products such as gasoline and mineral spirits contribute to sewer gas hazards. Sewer gases are of concern due to their odor, health effects, and potential for creating fire or explosions. Sewer gas is typically restricted from entering buildings through plumbing traps that create a water seal at potential
Vertical damp proof barrier Vertical damp proof barrier The purpose of a Vertical Damp Proof Barrier is to prevent the ingress of damp and water into subterranean structures such as basements, cellars, tunnels and earth shielded buildings. (Also known as Earth sheltered buildings). Traditionally, this took the form of several coats of bitumous paint or tar. This, though cheap, has the disadvantage that any movement in the structure or joints is likely to rupture the paint so allowing water to enter. Modern solutions take the form of a plastic membrane, often pre-coated with adhesive and a "peel off" paper that is applied to the