Waste Pipe Smell

[injac]

We started renting a terraced house back in February. The last week or so we noticed a methane/sewage smell in the guest room. This seems to be stronger if the toilet is flushed.

This guest room is next door to the bathroom and the soil pipe from the toilet actually goes through the wall to the guest room and in turn outside. The pipe is boxed up and if you put your nose to it the smell is stronger.

Any ideas what causes this? Incidentally we have currently got an issue with a mysterious pool of water that keeps appearing in the cellar which doesnt appear linked to rain water etc. It comes from below ground and doesnt appear to be sewage water but could be sink water...

Any ideas folks?
Andy

 

[Hugh Jaleak]

Does the soil pipe from the toilet go up and through the roof? If not then it's likely to be fitted with an Air Admittance Valve, these are designed to allow air in to the system when required but keep smells out. If it's stuck open then could account for the smell inside the property.

Leak in cellar could be anything, but without testing the drains it would be difficult to rule a broken/leaking drain out. Depending on age of property, earlier buildings often have rainwater draining into the sewer rather than a seperate rainwater system. What leads you to suspect 'sink water' ?