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
Damp (structural) timber surveyor with a CSRT qualification. Processes for diagnosing rising damp in buildings are set out in BRE Digest 245. Most forms of dampness can be prevented by thoughtful building design and careful construction. In the UK, well built modern houses include damp proofing in the form of a synthetic damp-proof course (DPC), about 15 cm above ground level, to act as a barrier through which water cannot pass. Slate or "engineering bricks" with a low porosity were often used for the first few courses above ground level, and these can help minimise the problem. There are many approaches to