Our basement smells like sewage on occasion. We do have a living area and guest bedroom in the basement but are unable to use it at times due the smell.
The bathroom in the basement that utilizes a pump to pipe the effluents to the septic system. This does not appear to have any leaks, all the pipes seem to be sealed and the vent is not clogged on the roof. . Despite our best efforts to locate the problem we / plumber have been unable to locate it.
The smell occurs most often in the winter of when we have extreme weather changes from cold to warm.
Any assistance would be greatly appreciated.