I bought a second-hand house 8 years ago. it is a 3 bed detached bungalow. In the last year a foul smell can be got in the hall, utility room and the back bedroom. This smell appears when it rains after a spell of dry weather and can last 3-4 days. The smell is like a mixture of sewage/stagnant water/gas and it is quite unbearable. I know smells of this nature have been talked about in previous threads but none of the solutions raised are of benefit to me. has anyone any suggestions as to where this smell could be originating from. I would be most grateful for any ideas out there.