What are common causes of sewage smells in the property?

Pro Heating & Plumbing Ltd & Pro-Drain Ltd answered the question "What are common causes of sewage smells in the property?"

In our experience of investigating this particular drain problem the most common causes of unpleasant drain smells within a property are incorrectly capped off disused sections of the drainage system for example manhole chambers and gullies beneath raised floors and property extensions, we have also identified on numerous occasions stub stack pipes to have no end caps or air admittance valves - just an open pipe venting the drainage system behind an internal stud wall. Suitable ventilation of a drainage system or lack of can also be an issue, the lack of ventilation can cause siphoning of shower, bath or sink traps when a toilet or other amenity is flushed or discharged this can be corrected with the installation of an air admittance valve which will open under negative pressure.