Since my new renovation 9 months ago, and particularly over the last 2 weeks of incessant rain, one of my bathrooms has a damp and sometimes odorous smell. It appears to be coming from the outflow pipe from my wash hand basin.

 

This is an image of the pipe:

 

I have considered putting in a pee trap, like this:

 

 

And Lazada sells this:

 

 

I cannot seem to get a definitive answer from 2 contractors I have spoken to about it.

 

Would be grateful for any thoughts or comments from those who may have tackled this problem themselves.

 

I live in a condo in Bangkok on a high floor. It is possible the contractor who did the renovation made the outflow into a sewage pipe instead of a sanitary pipe. There is no floor drain pipe, except in the shower, and that does not have any odor.

 

5 minutes ago, samtam said:

I have considered putting in a pee trap, like this:

You already have a p trap   but maybe they cut the downpipe (top arrow) too short  so it doesn't sit in the water that accumulates below the  pipe that goes out towards the wall   which allows the smells to pass buy un-hindered   unscrew the bottom piece (bottom arrow ) and clean out any crud  and see if the downpipe extends far enough.

Well, thank you! I will have a go.

i bought something like the Lazada plastic thingy from a building supply for around 100 baht if i remember correctly ( but maybe a bit more).   Kinda works but I was always sceptical that is was as

good as a solid P trap.

what johng points out is correct.... give it a try .

 

what i really choose to use when there is space is a PVC  homemade option ....  they do sell the "parts" which you can assemble yourself,  with the U shaped section have a screw plug for cleaning out when needed (hardly ever, but in a kitchen good to have) .    I like that set up as i am sure there is always

water in it to keep the smell from rising up.   also stronger,  and safer for pouring baking soda/vinegar down occasionally.  

yours is just a bathroom sink,  usually the trap shown works well enough

 

Edited October 19, 20205 yr by rumak

1 hour ago, johng said:

You already have a p trap

It isn’t a “P” trap but it is a bottle trap.

2 hours ago, samtam said:

one of my bathrooms has a damp and sometimes odorous smell. It appears to be coming from the outflow pipe from my wash hand basin.

While the Crome down pipe could be set too short, it’s also quite possible that the internal plastic parts could be missing or broken.

Have always been a big fan of the P trap, you could get the parts to change it, won't cost much and shouldn't take long to change.

Just now, 4MyEgo said:

Have always been a big fan of the P trap, you could get the parts to change it, won't cost much and shouldn't take long to change.

be careful with your P's and Q's ................. or you will be put right by the guy with the long avatar.

or is it user name?   hmmmmm   better google that 

Do have a vent pipe fitted....and if so is it clear.

 

https://theplumbinginfo.com/plumbing-vent-diagram/

13 minutes ago, rumak said:

be careful with your P's and Q's ................. or you will be put right by the guy with the long avatar.

or is it user name?   hmmmmm   better google that 

2 hours ago, Surelynot said:

Do have a vent pipe fitted....and if so is it clear.

 

https://theplumbinginfo.com/plumbing-vent-diagram/

surely ....not.   555   i was wondering if anyone was going to point this out.   I would say that they never do this (have a vent)  in Thailand,  but i am sure someone will tell me they have seen it done.

 

As the diagram shows, this would send the odors up and out the vent opening top of house. 

Anyone here have that in their home?  

 

Drains in almost all the hotels i used to stay would have smelly shower drains... yuck 

 

Also need to show the extension of the diagonal PVC pipe the bottle trap is connected to.

 

There's a pretty good chance it goes low enough to trap a bubble that would completely defeat the bottle trap.

 

About once a month it is baking soda, vinegar and hot water in the drain pipes for me.....and a fan running in the general direction in the morning after my rinse off.....seems to do the trick? ????????????????????????????????

13 minutes ago, chicowoodduck said:

About once a month it is baking soda, vinegar and hot water in the drain pipes for me.....and a fan running in the general direction in the morning after my rinse off.....seems to do the trick? ????????????????????????????????

They sell an enzyme/bacteria powder in MR. DIY that works wonders in keeping drains and pipes clear...I toss some in all the drains every 3 months or so.

I've been experiencing bad odor in my bathroom as well. I'm unsure what to do and have had contractors here to check it out. They were useless. When I use the exhaust fan in that room, with the door closed, I'm convinced it draws air in thru the pipes from outside. Since there is no P trap anywhere in my system it's the only conclusion I can come to. I hate it and am considering moving to be done with it all.

13 hours ago, rumak said:

surely ....not.   555   i was wondering if anyone was going to point this out.   I would say that they never do this (have a vent)  in Thailand,  but i am sure someone will tell me they have seen it done.

 

As the diagram shows, this would send the odors up and out the vent opening top of house. 

Anyone here have that in their home?  

 

Drains in almost all the hotels i used to stay would have smelly shower drains... yuck 

 

Imagine all those poor guys going in quarantine in these hotels...... 55555555

Here is a photo of my "homemade" system....... this one small sink in utility room

 

If in kitchen or bathroom a cabinet will hide the not so glamorous drain...... but it works great,

has a drain plug, and is strong.  

i use larger size for kitchen sink

 

14 hours ago, rumak said:

surely ....not.   555   i was wondering if anyone was going to point this out.   I would say that they never do this (have a vent)  in Thailand,  but i am sure someone will tell me they have seen it done.

 

As the diagram shows, this would send the odors up and out the vent opening top of house. 

Anyone here have that in their home?  

 

Drains in almost all the hotels i used to stay would have smelly shower drains... yuck 

 

I had a vent pipe in my last house - projecting above the roof, but it's the only one I've ever seen here.

 

The main reason for the vent is to prevent the water going down the drain creating suction and pulling out the water from the seal.

 

As the OP mentions he's on a high floor, this may be the issue.  If toilets are connected to the same downpipe, when they are flushed the descending water may suck out the waterseal.  But you can normally here an intermittant gurgling sound from your basin if this is the issue?  Solution is to close the plug when it's not in use, as adding a vent to a condo can be difficult.

 

I was going to make a comment about the OP's P-trap being sucked off, but decided to stay classy.

5 hours ago, ehs818 said:

I've been experiencing bad odor in my bathroom as well. I'm unsure what to do and have had contractors here to check it out. They were useless. When I use the exhaust fan in that room, with the door closed, I'm convinced it draws air in thru the pipes from outside. Since there is no P trap anywhere in my system it's the only conclusion I can come to. I hate it and am considering moving to be done with it all.

Do you have a floor drain? One of mine causes a smell if I don’t top the water up every few days.

The water in your bottle trap can be sucked out by a vacuum in the soil and vent pipe it's connected to. If the smell is worst after a downpour it could be that you are connected to a combined soil vent and rainwater pipe or there is no vent on your soil pipe

On 10/19/2020 at 4:10 PM, johng said:

You already have a p trap   but maybe they cut the downpipe (top arrow) too short  so it doesn't sit in the water that accumulates below the  pipe that goes out towards the wall   which allows the smells to pass buy un-hindered   unscrew the bottom piece (bottom arrow ) and clean out any crud  and see if the downpipe extends far enough.

Thanks again. Had it checked out, and it is working well. My building technician said this bottle trap is better than the p trap. Whilst we were in the bathroom I noticed the odor was more prominent from the new wc, and as there are no visible pipes/holes, he had a look with his camera, and there were 4 unsealed parts. He had now sealed these with silicone, and so far, (5 hours later), the smell has ceased.

3 hours ago, samtam said:

Thanks again. Had it checked out, and it is working well. My building technician said this bottle trap is better than the p trap. Whilst we were in the bathroom I noticed the odor was more prominent from the new wc, and as there are no visible pipes/holes, he had a look with his camera, and there were 4 unsealed parts. He had now sealed these with silicone, and so far, (5 hours later), the smell has ceased.

I found those 4 round holes in our COTTO toilet and thought that was the cause of a smell I got sometimes. I eventually sorted that smell by completely removing the toilet and then refitting using the correct COTTO Kit. Thai plumbers always seem to throw away the important very sticky seal (gasket Big in pic) as it is difficult to use and they don't think it is necessary.. 

 

The only place that I have managed to find that kit is at the COTTO shop which is not that far from Don Muang Airport. The Kit is No2 in the pic and sealing around the bowl/floor join is also very important.

 

Edited October 20, 20205 yr by PFMills
added pic

22 minutes ago, PFMills said:

I found those 4 round holes in our COTTO toilet and thought that was the cause of a smell I got sometimes. I eventually sorted that smell by completely removing the toilet and then refitting using the correct COTTO Kit. Thai plumbers always seem to throw away the important very sticky seal (gasket Big in pic) as it is difficult to use and they don't think it is necessary.. 

 

The only place that I have managed to find that kit is at the COTTO shop which is not that far from Don Muang Airport. The Kit is No2 in the pic and sealing around the bowl/floor join is also very important.

 

HomePro do have toilet seal rings.

 

https://www.homepro.co.th/m/p/1106597?lang=th

My bathroom odour problem (Condo) was from the floor drain that appears to be fitted in most Thai installations. I have cured it with an inline stainless steel trap from Lazada (370 baht):

https://www.lazada.co.th/products/i616484093-s1170740099.html?urlFlag=true&mp=1

 

10 hours ago, Kinnock said:

Solution is to close the plug when it's not in use, as adding a vent to a condo can be difficult.

I had trouble with one of the toilets sucking the water from the bowl after flushing, due to a missing vent valve. Solved it by adding a small check valve for air at the top of the trap. No odor comes out as it's normally closed, air only flows in when there's a small vacuum. That could solve it, but the pipe seems to be metal so a drill+some epoxy is needed to install one.

4 hours ago, samtam said:

 Whilst we were in the bathroom I noticed the odor was more prominent from the new wc, and as there are no visible pipes/holes, he had a look with his camera, and there were 4 unsealed parts. He had now sealed these with silicone, and so far, (5 hours later), the smell has ceased.

Ah. Missing wax seal. Available from lazada among others. Somchais rarely bother to put them ( or even use bolts to tie it down ), instead they silicone or use caulk to glue the seat down.

https://www.lazada.co.th/products/wax-ring-toilet-gasket-i1638008900-s4526190369.html?spm=a2o4m.searchlist.list.6.33382cbcTqy1oF&search=1

 

All that to save 60 baht.

 

I chose American Standard as the throne because it had an installation kit that includes a rubber seal that fits tight inside the PVC downpipe. 

Edited October 20, 20205 yr by DrTuner

Mine is American Standard too, and I know they used the seal between the sewage pipe and the WC, because there was a size difference.

 

But on either side of that there are 4 square-ish recesses (arrowed 2 of them), and these were filled with  silicone, which seems to have sorted the problem.

 

Of all the trades doing the renovation the plumber was the most scattered, and would open the packages with all the pieces and leave them lying around, so I tried to watch him like a hawk, when the site manager wasn't there. His compensating factor was that he was very good at laying tiles and cutting the patterns exactly. 

I replaced the compact Thai (asian) drain in under one of my sinks when we first moved in 15 yrs ago. It's not really hard. I preferred it because of the full opened pipe and the obvious 'P' shaped trap. Scraps and mold don't cake up and block the drain. We still have smells, but it's from the poorly installed shower and toilet drains in the bathroom just below. We installed a extraction fan down there and I try to get my wife to stick a stopper over the shower drain when not in use.