Sewer Gas Mystery in 5 story shophouse - 2nd floor only

[jaf3]

I have a guest house near Sathorn Soi 1, a shophouse from 1982. I installed new plumbing when I renovated it in 2006.

The washing machine is on the 6th floor (rooftop). For some reason, when someone runs the washing machine, we get sewer gas bubbling up from the toilet and/or the shower drain on the 2nd or 3rd floor - the problem moves around between the two floors.

We have emptied the septic tank. We have put the 'good bacteria' in the septic tank. Does not change the situation.

The smell persists and seems to be tied to when the washing machine is draining a load of water from the machine.

Any insight into what causes this and how to solve this problem?

Is it simply a question of ripping up the floor an installing a U-Trap?

I dont see how the ping pong ball idea (no comments pls.....) solution mentioned in this thread would help if the problem is coming from a toilet?

http://www.thaivisa.com/forum/topic/431529-sewer-gas-remidies-in-condo/

Anyone out there - retired plumbers? - I could hire to help me fix this?!

thanks,

[Mrjlh]

A speculative guess would be the septic tank is not properly vented. Run off water is forcing sewer gas back up through the sewer pipes out through the toilets and sinks. Check to make sure the septic tank vent pipe goes all the way and above the roof line. Also check for a break in the pipe at around the second floor. That's would be my only guess.

[willyumiii]

A U trap as you call it is always a good idea.

I am surprised at how many places in Thailand do not use this simple method of preventing " that smell".

Mrjlh sounds like he is also on the money.A broken, nonexistent or malfunctioning vent pipe will provide a stink as well....if you have traps or not.

The work is pretty easy to do yourself.

Google has good information and drawings on how to make and install your own traps with PVC.

Choke dee!

[jaf3]

Thanks guys - the septic tank vent sounds like the culprit and the easiest to try to fix first - I will report back

On that note, does anyone know a plumber who knows their stuff here in Bangkok? I will pay (almost) anything to get this done right!