In one answer to a question how to find where sewage gas coming from. Some body said need to do a smoke test. Could you please let me know what is a smoke test and how to do it. I need to find where sewage gas come from in my basement?
Thanks.

I haven't doine a smoke test since I worked at my dads shop back in the 40's.
As I recall we put a yellow smoke bomb in the house cleanout and checked around toilets and stacks for any sign of yellow smoke. I wasn't aware they still did smoke tests. Regards, tom

Check where your vent stack exits your home. It should go staright up through the roof and not into the eaves. Make sure the vent is unobstructed and working. Short of a broken pipe or dry trap there aren't many other sources of sewer gas. If you have a floor drain connected to the sewer be sure to put some bleach/water into that drain. Periodically add water to all sinks not tregularly used. The traps can evaporate over a long time.