Plumbing / drain / sewer issues

[WhiteLotusLane]

Ok, problem:

I have a nice newly instralled bathtub on the second floor bathroom, but when I fill it up and then drain it, a little water comes back through the floor-drain of a bathroom downstairs. It also makes all kinds of interesting noises.

What needs to happen? Can the drain pipes need unclogging? How would that happen and who would typically do that? Or would the cess pit need emptying? Or both?

I also noticed the toilets don't drain very fast when flushing, though that could have something to do with the type; not sure.

HELP!

[sledge]

I think you need a back vent put in; that is another pipe cut in between the two connections going to the atmosphere about 600mm above the top bath plug hole.

[dirtydog]

Both probably need a vent pipe, also maybe your cesspits and soakaway may not be vented.

[WhiteLotusLane]

that is another pipe cut in between the two connections going to the atmosphere about 600mm above the top bath plug hole.

Sorry, which two connections you mean? You mean from in between where the bathtub drain pipe connects to the drain for the second floor? And then up for 60 cms? Where would that pipe end then, just into the air on the outside wall of the house?

I'm not very experienced with this sort of thing..

[sledge]

There should be a vent that tees off just after the trap of the new bath. This can then be teed back into the main vent pipe above the overflow level of bath overwise you can also terminate it outside at same level. If the waste pipe is to small when you let the water go from bath it will fill up the pipe and act as a plug travelling down the waste and will cause siphonage of other traps, gurguling noises and water coming out of other plugs therefore the vent allows air into the system.

[WhiteLotusLane]

Thanks!! It's much clearer now.

What I'm wondering about now if my house has a vent-pipe / vent system at all? Would it be possible for a typical 3 million baht, 2 floor house in a typical gated community NOT to have a main vent pipe or is that out of the question?

I have to say even before the bathrub installation there was an issue sometimes with some smells coming out of drains in some of the bathrooms. This was/is an intermittend problem.

What would be the best course of action to check if a venting system / vent pipe is in place and in proper working condition (could be blocked, etc.)? If no venting system is in place at all, should I get one, or just figure a way to just vent near where the bathtub is?

[ThisOldHouse]

Thanks!! It's much clearer now.

Even clearer is the Drain Waste Vent (DWV) system drawing and a good explanation of how it all works at

hometips.com/hyhw/plumbing/74drain.html

I would've posted the drawing here, but I'm not 10+ yet

Chok Dee
TOH

[WhiteLotusLane]

So anyway, is venting so ubiquitous in Thai construction then I can expect it to be there, or is this an area that I need to get a professional to look at. It may be beyond the capabilities of the people who did the bathroom tub & furniture?

[Whiteshiva]

I have to say even before the bathrub installation there was an issue sometimes with some smells coming out of drains in some of the bathrooms. This was/is an intermittend problem.

This could happen if the water seal in the U-tube in the drain has dried out. A few dl of water normally sorts that problem out.

The backflow from your d/s floor drain could be due to a partial restriction or blockage in the d/s piping. In other words, the water drained from u/s cannot pass through the downstream piping fast enough, and the hydrostatic head makes the excess water flow out of the downstairs drain.

This may also happen if the plumbing has been incorrectly installed. If so, it may be more trouble fixing than it is worth.

Try flushing the drains with a special unblocking fluid (several brands available on the market) - they sell it at most supermarkets and HomePro shops. This may clear the drains.

[WhiteLotusLane]

I think I've made progress. An air vent was installed somewhere, and it also turned out that the drain toward the village sewer was clogged. (Water from drains goes there, toilet drains into cess pit).

Apparently getting state of the art pipe cleaning equipment is expensive, so instead they used a long steel bar and replaced a section of pipe, which was a lot cheaper. Also copious amounts of draino were used.

Result: Everthing drains a lot faster now, with less gurgling noises and no water coming back up anywhere.