Sewage smell in condo - any ideas?

[Globalist]

Looking for someone experienced with plumbing who can help shed some light on this:

New high rise condo, unit on high floor. Strong and very bad smell in toilet on work-days mornings and evenings ("peaks" around 8 AM and 8 PM). No smell at other times, and no such smell in any other rooms, including the adjoining shower/bathroom, nor in the kitchen. No bubbles coming up through the water in the toilet bowl. The toilet bowl, a new Cotto model, functions properly.

Given the times this occurs, I assume the smell is related to sewage.

There are three drains in the toilet area:

- Toilet bowl drain.

- Floor drain with standard simplified U trap under the lid.

- Hand basin (sink) drain with U trap.

To investigate the origin, I did the following:

1) Sealed off the floor drain by filling water in the simplified U trap + using several layers of quality cling film on the drain opening as well as on both sides of the lid + taped liberally with gaffa tape on the top of that + placed additional covering items on top of the lid.

In my mind, it would be hard for gas to get trough in any significant quantities.

2) Plugged the sink and filled it with water. No bubbles. This should be gas-tight.

I left it like that for many days. The smell still prevails.

This to me points to the toilet bowl drain, but I'm still not completely sure.

I noticed that in Thailand they use completely integrated toilet bowls, i.e. the connection between bowl and drain is invisible. It beats me how they can ensure a tight seal with that design, but they then seal all around the bottom against the toilet floor by putting cement/plaster to the floor. It seems like the idea is that in case the toilet bowl seal would not be tight, it doesn't matter since the outer cement/plaster seal will hold.

I added two layers of silicon on the cement/plaster seal of the toilet bowl to see if there'd be any difference.

No difference.

So my question is, can the toilet bowl seal be leaky and sewage gas come up "within/under" the toilet bowl and push out through the plaster/cement floor seal (and also through the additional silicone) ?

Or am I on the wrong track? Are the other drains still possible culprits, was my floor drain cover insufficient? Can it be something else, like the extractor fan vent (the smell is worse when the fan is off, but that seems quite natural to me)?

Any ideas would be very much appreciated..

[rayongchelsea]

We had that problem in our condo.

No seals ( they had been stolen by the subcontractor !) the toilets had just been cemented in and in some no u pipe or not fitted correctly.

The smell came and went.

No problems since.

[IMHO]

Do you notice the extraction fan slowing down or laboring when the bathroom door is closed vs open? if so, it could be sucking intake air from drains rather than under the door - in which case the fix is simple - cut the door shorter

[Globalist]

Do you notice the extraction fan slowing down or laboring when the bathroom door is closed vs open? if so, it could be sucking intake air from drains rather than under the door - in which case the fix is simple - cut the door shorter

Thanks, tried that already. Smell is worse with fan off, regardless of if door is open or closed.

[Globalist]

We had that problem in our condo.

No seals ( they had been stolen by the subcontractor !) the toilets had just been cemented in and in some no u pipe or not fitted correctly.

The smell came and went.

No problems since.

Thanks, you wrote "no problems since", but you didn't say since what...? :-P

(Also, "no u-pipe" can not be an issue for a toilet bowl since a toilet bowl is in itself an S- or U-trap by design. "Not fitted correctly" can be a problem though.)

[rayongchelsea]

We had that problem in our condo.

No seals ( they had been stolen by the subcontractor !) the toilets had just been cemented in and in some no u pipe or not fitted correctly.

The smell came and went.

No problems since.

Thanks, you wrote "no problems since", but you didn't say since what...? :-P

(Also, "no u-pipe" can not be an issue for a toilet bowl since a toilet bowl is in itself an S- or U-trap by design. "Not fitted correctly" can be a problem though.)

Once we fitted the correct toilet seal by cotto the problem of smells coming from the bathroom stopped completely.Since we put in the new seal.

Ok. I got a bit jumbled up there.

[Globalist]

We had that problem in our condo.

No seals ( they had been stolen by the subcontractor !) the toilets had just been cemented in and in some no u pipe or not fitted correctly.

The smell came and went.

No problems since.

Thanks, you wrote "no problems since", but you didn't say since what...? :-P

(Also, "no u-pipe" can not be an issue for a toilet bowl since a toilet bowl is in itself an S- or U-trap by design. "Not fitted correctly" can be a problem though.)

Once we fitted the correct toilet seal by cotto the problem of smells coming from the bathroom stopped completely.Since we put in the new seal.

Ok. I got a bit jumbled up there.

OK thanks! So the gas did push through the cement, that's what I suspect is happening in my case too.

[WorkingTourist]

OK thanks! So the gas did push through the cement, that's what I suspect is happening in my case too.

Were you able to confirm this?

I have experienced sewage smells most of the places that I have stayed in Thailand, and as I am looking into doing an en suite bathroom layout (without a door), I would like to get a little wiser about what the problem is with thai plumbing that seem to exacerbate this problem (so I can hopefully avoid it).

Previously I thought the issue was with the floor drain’s U-lock drying out, which I would expect is also an issue. Do people regularly fill water into their floor drain to avoid this? Or do I overestimate how short it takes for the water to evaporate (I am btw in CM where the humidity isn’t high)?

[IMHO]

OK thanks! So the gas did push through the cement, that's what I suspect is happening in my case too.

Were you able to confirm this?

I have experienced sewage smells most of the places that I have stayed in Thailand, and as I am looking into doing an en suite bathroom layout (without a door), I would like to get a little wiser about what the problem is with thai plumbing that seem to exacerbate this problem (so I can hopefully avoid it).

Previously I thought the issue was with the floor drain’s U-lock drying out, which I would expect is also an issue. Do people regularly fill water into their floor drain to avoid this? Or do I overestimate how short it takes for the water to evaporate (I am btw in CM where the humidity isn’t high)?

There are a few things you can do to avoid these types of smells. This page by SCG sums it up well: http://www.scgexperience.co.th/th/blog/detail.aspx?id=22&post=366

The two main things that are commonly overlooked are:

1) Always use P traps on every single floor, bath or shower drain - don't rely on those u-trap drain lids (in addition, close your sink/bath plugs when not in use).

2) Always install an additional ventilation pipe on the sewer pipe, so the gases have somewhere to go (other than trying to force their way out of the toilet/pipe junction).

Edited December 20, 2014 by IMHO

[Globalist]

OK thanks! So the gas did push through the cement, that's what I suspect is happening in my case too.

Were you able to confirm this?

I have experienced sewage smells most of the places that I have stayed in Thailand, and as I am looking into doing an en suite bathroom layout (without a door), I would like to get a little wiser about what the problem is with thai plumbing that seem to exacerbate this problem (so I can hopefully avoid it).

Previously I thought the issue was with the floor drain’s U-lock drying out, which I would expect is also an issue. Do people regularly fill water into their floor drain to avoid this? Or do I overestimate how short it takes for the water to evaporate (I am btw in CM where the humidity isn’t high)?

I haven't confirmed it yet. My suspicion is now on one of the bolts, since it looks as if sewage gas is leaking through the bolt hole. That is of course also more likely than leakage through cement.... :-P

I intend to re-install the toilet within one week to try to fix the root-case, using a proper pan collar seal. Hope to report the result soon.

In my case, I don't suspect the floor drain. Note that this can mean either that the in-lid-U-drain actually works or that the floor drains are connected to a separate main drain from the toilet drain. I don't regularly fill water in it, although the regular weekly cleaning obviously results in water in the lock.

[WorkingTourist]

There are a few things you can do to avoid these types of smells. This page by SCG sums it up well: http://www.scgexperience.co.th/th/blog/detail.aspx?id=22&post=366

The two main things that are commonly overlooked are:

1) Always use P traps on every single floor, bath or shower drain - don't rely on those u-trap drain lids (in addition, close your sink/bath plugs when not in use).

Thanks a lot for the information, I was unaware of the important role of proper venting of the pipes (not being a plumber).

Can you elaborate on what exactly a “U-trap drain lid” is?

To me a U-trap seems equivalent to a P-trap, just with intake coming horizontally instead of vertically.

[IMHO]

There are a few things you can do to avoid these types of smells. This page by SCG sums it up well: http://www.scgexperience.co.th/th/blog/detail.aspx?id=22&post=366

The two main things that are commonly overlooked are:

1) Always use P traps on every single floor, bath or shower drain - don't rely on those u-trap drain lids (in addition, close your sink/bath plugs when not in use).

Thanks a lot for the information, I was unaware of the important role of proper venting of the pipes (not being a plumber).

Can you elaborate on what exactly a “U-trap drain lid” is?

To me a U-trap seems equivalent to a P-trap, just with intake coming horizontally instead of vertically.

U trap drain lids are the standard in TH, and work like this:

The are several deficiencies with these though:

1. so little water is held in the "u" that it can easily evaporate.

2. Because floors are sloped, they hold even less water than their design suggests.

3. If the lid is all fitting, it doesn't work.

4. They get blocked up by things like hair & soap pretty quickly

Edited December 22, 2014 by IMHO

[Beardog]

The most common problems in Thailand are the 4"pipe outside diameter isn't a true 4" or 3" what ever they used to put the toilet together. I do my own toilets for that reason making sure that the pipe fitting the toilet flange has oil based silicone around the pipe to make damn sure it is sealed tight as a welded joint. The second part that you may have noticed is the holes that bolt down the toilet are not sealed afterwords & methane odors will come up through the open holes. & third that Thai's are infamous for is not paying attention to the gasket & installing the toilet with the gasket cockeyed & crushed 1/2 of the gasket & the other half seats in properly. I like overkill so I always put extra gasket sealer(black auto silicone-oil based on the gasket if it is rubber. Out of 11 toilets no odors to date. Except the learning curve when the contractor did the job & his help was drinking all night & playing cards. Crushed gasket no pipes had good seals glued the toilet in with grout & no bolts holding the 2 toilets down. So the school of hard knocks. Re did everything to western standards & problem went away. U traps are essential to your shower drain & in condos they hardly ever put them in so you are force to use aftermarket ways to keep the odors out.

[Globalist]

The most common problems in Thailand are the 4"pipe outside diameter isn't a true 4" or 3" what ever they used to put the toilet together. I do my own toilets for that reason making sure that the pipe fitting the toilet flange has oil based silicone around the pipe to make damn sure it is sealed tight as a welded joint. The second part that you may have noticed is the holes that bolt down the toilet are not sealed afterwords & methane odors will come up through the open holes. & third that Thai's are infamous for is not paying attention to the gasket & installing the toilet with the gasket cockeyed & crushed 1/2 of the gasket & the other half seats in properly. I like overkill so I always put extra gasket sealer(black auto silicone-oil based on the gasket if it is rubber. Out of 11 toilets no odors to date. Except the learning curve when the contractor did the job & his help was drinking all night & playing cards. Crushed gasket no pipes had good seals glued the toilet in with grout & no bolts holding the 2 toilets down. So the school of hard knocks. Re did everything to western standards & problem went away. U traps are essential to your shower drain & in condos they hardly ever put them in so you are force to use aftermarket ways to keep the odors out.

Thanks for this input!

I had a guy re-install my toilet, to no avail..

Because the toilet (Cotto) is intergrated (you can't see the horn unless from underneath), very heavy, and that particular bathroom space very narrow, it became very difficult to guarantee a good seal between the horn and the pipe.

A non-wax gasket was tried but the height became to great due to toilet bowl design. Ended up using only wax gasket, which I suspected might only have a limited effect.

So I put my hopes to the Thai "remedy" of "white cement" around the toilet base and this time sealed & covered the bolts with wax.

Still the periodic odour is there. Most likely coming through wax and/or "cement"...

Clearly I need to re-do, and get the drain connection completely sealed, since it's the root-cause.

Considering buying a 2-piece toilet, where you have some control over the drain connection. If something goes wrong, no need to re-installt the entire toilet bowl.

Any ideas/thoughts?

[KittenKong]

U trap drain lids are the standard in TH, and work like this:

The are several deficiencies with these though:

1. so little water is held in the "u" that it can easily evaporate.

2. Because floors are sloped, they hold even less water than their design suggests.

3. If the lid is all fitting, it doesn't work.

4. They get blocked up by things like hair & soap pretty quickly

I find that the other problem with these drain lids in my building is that the main downpipe often doesn't have sufficient (any?) ventilation at the top, so there can be a significant syphon effect from downwards flowing water that can suck the water out of the trap in the lid and allow gases to pass back up into the bathroom.

Two of these solved that problem for me:

[Globalist]

For those interested in toilet bowl installation in condos, here's the conclusion:

On the second attempt, the root cause was found. The wall-to-drain pipe distance was 27 cm rather than the 30 cm that almost all toilet bowls are designed for.

That made it virtually impossible to get a good seal at the floor drain.

After buying and installing a toilet bowl with an adjustable rough-in distance, problem was solved, smell gone!

[Sophon]

For those interested in toilet bowl installation in condos, here's the conclusion:

On the second attempt, the root cause was found. The wall-to-drain pipe distance was 27 cm rather than the 30 cm that almost all toilet bowls are designed for.

That made it virtually impossible to get a good seal at the floor drain.

After buying and installing a toilet bowl with an adjustable rough-in distance, problem was solved, smell gone!

In a situation like this, and if not wanting to change the toilet, you can buy off-set flanges that will correct the problem.

Sophon

[Globalist]

For those interested in toilet bowl installation in condos, here's the conclusion:

On the second attempt, the root cause was found. The wall-to-drain pipe distance was 27 cm rather than the 30 cm that almost all toilet bowls are designed for.

That made it virtually impossible to get a good seal at the floor drain.

After buying and installing a toilet bowl with an adjustable rough-in distance, problem was solved, smell gone!

In a situation like this, and if not wanting to change the toilet, you can buy off-set flanges that will correct the problem.

off-set flange.jpg

Sophon

Yes, that's definitely an alternative solution I also considered.

But I got the impression that it would lead to a higher risk of blockage and more difficulty in clearing blockage, so I chose the flexible rough-in toilet solution instead.

[kannot]

fer fawkes sake ........HERE the correct fitted part.s..............NOTE Thais couldnt plumb in a plug in a sink without a problem

BOG SEAL plate for the floor screwed and silconed down followed by wax seal and P TRAPS for grey water readily available.

Your condo was built by cretinous morons who have ZERO skills as most Thai construction workers I have seen .

Ive done everything myself due to this inate Thai "skill" of bodge it

Other photo shows P traps and breather pipes use 2 inch pipe for all floor drains

The "Thai way" = pump as much silicone into any orifice as you can as this is a known "cure all" for any water problem.

Edited February 8, 2015 by kannot

[Prapaexpert]

Many time the problem can be in the Construction.

If the drain ventilation when the neighbor flush ther toilet. There is vaccum pressure to the P-trap. that get Heavy smell in the morning and the night when neigbour use their toilet as most. If the problem get solved everytime if you flush water in your drain. Then it is probarly this problem?

Can be solved by Contact manager of the house to get a plumber to look about this.

Here is a sample wideo what happend with this.

https://www.youtube.com/watch?v=vjmrl6K1w-o

Janne PrapaExpert 021054545

[OliverKlozerof]

Just moved into a new apartment on 9th floor of 16 floor building. OP's problem is same as mine, I think.

[OliverKlozerof]

FYI, I found the answer to the smell in my apartment's bathroom: In the back side of the toilet there is a space...I got down on hands and knees and managed to look back there. There were 2 small holes down into the floor, on either side of the toilet, about the size of a 1 baht coin. I just cleaned and dried around them, then put duct tape (gaffer tape in UK?), over them. Voila--no more smell. Finally!

[Artisi]

FYI, I found the answer to the smell in my apartment's bathroom: In the back side of the toilet there is a space...I got down on hands and knees and managed to look back there. There were 2 small holes down into the floor, on either side of the toilet, about the size of a 1 baht coin. I just cleaned and dried around them, then put duct tape (gaffer tape in UK?), over them. Voila--no more smell. Finally!

You beat me to it, I had a problem with one of the toilets installed in our home, exactely the same - the holes in the base of the toilet are for hold-down bolts which aren't used when the toilet bowl is put onto silicone rubber for attachment to the floor. One had been blocked off using silicone but the other must have missed out - I simply got some cement based tile adhesive left over from the build and plugged the hole - problem solved in 2 minutes work.

[HardyHarhar]

Faulty U-trap or no U-trap is a real health safety issues. During the SARS crisis, some 300 people got infected via faulty bathroom U-trap drains at the Amoy Garden complex in Hong Kong.

If you can't redo the plumbing, I would recommend airing out the bathroom or the whole house as much you can during the day.

The trap implement is a good idea as well.

[Artisi]

On Monday, December 14, 2015 at 3:55 PM, HardyHarhar said:

Faulty U-trap or no U-trap is a real health safety issues. During the SARS crisis, some 300 people got infected via faulty bathroom U-trap drains at the Amoy Garden complex in Hong Kong.

If you can't redo the plumbing, I would recommend airing out the bathroom or the whole house as much you can during the day.

The trap implement is a good idea as well.

Something amiss with your comment, toilet bowls have an inbuilt "S" bend built in however, the comment in post 20 regarding a faulty sewage system installation can lead to problems.