Not really a DYI question, but I don't see any other place to post this.  Visiting Thailand, some condo and hotel room I stayed at had sewer smell coming from the bathroom.  It only happened in some rooms, and not the others.  Sometimes the smell would come and go, and in a few rooms it was there all the time and so bad that I had to change the room.  I've never noticed this problem in the US or Europe, only in Thailand.  A quick Google search tells me how P-trap drains replaced S-traps decades ago in the West to eliminate the smell problem that was common with S-traps.  Is Thailand still using S-traps, or is there another reason for this?  I've noticed this problem in recently built hotels and condos, so it's not about old construction.

 

 

Edited April 11, 20224 yr by wn78

The smell is how you can tell if it's windy outside.

 

The main reason for the smell is that a great many Thai shower wastes have no trap at all.  For some inexplicable reason that doesn't always mean that they smell.  I have 2 bathrooms back to back, each with the shower waste in the floor.  One does not smell at all, the other does slightly - they both flow into the same waste pipe within 500mm of each other.  Fortunately, although the wastes are in the floor, I can get to them underneath and install a trap - when I get around to it.  For some, it means digging up the floor.

1 hour ago, KhaoYai said:

The main reason for the smell is that a great many Thai shower wastes have no trap at all.  For some inexplicable reason that doesn't always mean that they smell.  I have 2 bathrooms back to back, each with the shower waste in the floor.  One does not smell at all, the other does slightly - they both flow into the same waste pipe within 500mm of each other.  Fortunately, although the wastes are in the floor, I can get to them underneath and install a trap - when I get around to it.  For some, it means digging up the floor.

That's about the size of it, and like not installing an earth in the wiring of a house, not having a water trap to the shower waste water to prevent 'blowback' is all about saving money - that, or indolence.

Edited April 11, 20224 yr by SheikYabodyline

23 minutes ago, SheikYabodyline said:

That's about the size of it, and like not installing an earth in the wiring of a house, not having a water trap to the shower waste water to prevent 'blowback' is all about saving money - that, or indolence.

Perhaps it's because the smell doesn't affect Thais.

 

When they built a new accommodation block near where I lived in Lamphun, the outfalls for all the grey water went into a big open drain that flowed past our house, and eventually into the river.

Big problem in Malaysia and Indonesia.  I've been to newly-constructed shopping malls in the final phases of construction (wallboarding, shop windows being installed) and the place already smells of backed up toilets.  Those two countries seem to be in competition for the worst plumbers in the world.  Or maybe Indonesia gets the trophy, and Malaysia hires Indonesian plumbers.

 

 

20 minutes ago, bendejo said:

Big problem in Malaysia and Indonesia.  I've been to newly-constructed shopping malls in the final phases of construction (wallboarding, shop windows being installed) and the place already smells of backed up toilets.  Those two countries seem to be in competition for the worst plumbers in the world.  Or maybe Indonesia gets the trophy, and Malaysia hires Indonesian plumbers.

 

 

I noticed that, i vote for Malaysia, a friend of mine used to gag it was so bad

You can buy these drains for sinks, baths, showers, with a cup in them. Filled with water they act like a P-trap. They work not letting the smell out. Also the toilet pipes are sometimes just pushed into the riser pipes and the big rubber flange discarded. Many tricks you learn when you are not there for all the build and come back to a box of P-traps and rubber flanged still in the cupboard.

 

 

 

43 minutes ago, scubascuba3 said:

I noticed that, i vote for Malaysia, a friend of mine used to gag it was so bad

Also wet floors.  I used to think it was bad plumbing (the drain in the washbasin not connected to the drain pipe, for example -- pretty common there) but I harbor the impression that there is some kind of "good luck" in keeping the floors wet.  May sound crazy to an occidental, but if you've lived in this part of the world . . .

 

Wearing anything other deck shoes when out and and about betrays having a death wish, IMO.

 

 

Forgot to mention, whenever I had that problem in a hotel, I took a small towel, soaked it with water and covered the drain with it.

4 hours ago, KhaoYai said:

The main reason for the smell is that a great many Thai shower wastes have no trap at all.  For some inexplicable reason that doesn't always mean that they smell.  I have 2 bathrooms back to back, each with the shower waste in the floor.  One does not smell at all, the other does slightly - they both flow into the same waste pipe within 500mm of each other.  Fortunately, although the wastes are in the floor, I can get to them underneath and install a trap - when I get around to it.  For some, it means digging up the floor.

I agree what you point out about Thai floor wastes . 

Any p trap or s trap can dry out if not used . 

I am sure not a problem with hotels, but when building a house many don't believe in gluing the drain pipes.

9 minutes ago, itsari said:

I agree what you point out about Thai floor wastes . 

Any p trap or s trap can dry out if not used . 

Not quite any trap - I used waterless traps in my bathroom sinks.  They may encounter some form of failure in the future but it won't be drying out.

 

I can't remember the brand (it was 4 years ago) but I think these were the ones I used:

 

https://www.screwfix.com/p/osma-waste-valve-white-32-x-32mm/1819k

 

They're pricey for what they are but I didn't pay that much - I found some on Ebay.  Can't be sure on the size either but I think I used the 32mm ones - whichever it was, they will seal on the blue Thai pipe.

 

They can also be used horizontally.

Edited April 11, 20224 yr by KhaoYai

6 minutes ago, KhaoYai said:

Not quite any trap - I used waterless traps in my bathroom sinks.  They may encounter some form of failure in the future but they still work when they are dry.

 

I can't remember the brand (it was 4 years ago) but I think these were the ones I used:

 

https://www.screwfix.com/p/osma-waste-valve-white-32-x-32mm/1819k

 

They're pricey for what they are but I didn't pay that much - I found some on Ebay.  Can't be sure on the size either byt I think I used the 32mm ones - whichever it was, they will seal on the blue Thai pipe.

I have never heard of a waterless p trap before you mentioned them . However I can never imagine a p trap under the ground in a bathroom being replaced by a waterless p trap. I also wonder if the waterless p trap is allowed according to the regulations around the world . 

6 minutes ago, itsari said:

I have never heard of a waterless p trap before you mentioned them . However I can never imagine a p trap under the ground in a bathroom being replaced by a waterless p trap. I also wonder if the waterless p trap is allowed according to the regulations around the world . 

Correct, they are not designed for underground use.  I only mentioned them in response to your comment about traps drying out. I installed mine in the sink pedestals.

 

They certainly comply with UK regulations which are pretty stringent - I would think they comply with Thai regulations - if there are any ????.

Edited April 12, 20224 yr by KhaoYai

5 hours ago, KhaoYai said:

The main reason for the smell is that a great many Thai shower wastes have no trap at all.  For some inexplicable reason that doesn't always mean that they smell.  I have 2 bathrooms back to back, each with the shower waste in the floor.  One does not smell at all, the other does slightly - they both flow into the same waste pipe within 500mm of each other.  Fortunately, although the wastes are in the floor, I can get to them underneath and install a trap - when I get around to it.  For some, it means digging up the floor.

No trap because they dont know, or it isnt a real professional doing it.  Its all shoddy workmanship    but you nailed it exactly.   People buy condos never knowing in advance if this will be the case.  Then they get stuck for life or until they can unload on another sucker.

54 minutes ago, bunnydrops said:

I am sure not a problem with hotels, but when building a house many don't believe in gluing the drain pipes.

Dont believe or just dont know?

3 hours ago, bendejo said:

Big problem in Malaysia and Indonesia.  I've been to newly-constructed shopping malls in the final phases of construction (wallboarding, shop windows being installed) and the place already smells of backed up toilets.  Those two countries seem to be in competition for the worst plumbers in the world.  Or maybe Indonesia gets the trophy, and Malaysia hires Indonesian plumbers.

 

 

They built a new Central in Phuket near Laguna  a couple of years back, fancy restaurants, Tops food hall with Wagyu etc etc : "Porto de Phuket",

drains/toilets stank on day one. They fixed them 3 months ago. Stink just as bad today !

 

A lot of traps in Thailand are bell traps, there is no S/P trap under the floor.

Bell traps can dry out, and often people remove the bell when cleaning etc.

 

2 hours ago, WEBBYB808 said:

Dont believe or just dont know?

They glue the incoming. They figure not enough pressure on the drain side, will be held together by the dirt or concrete.

2 hours ago, Peterw42 said:

A lot of traps in Thailand are bell traps, there is no S/P trap under the floor.

Bell traps can dry out, and often people remove the bell when cleaning etc.

 

As said above almost all drains, if they have a trap at all, will be of the type above so work well if water does not dry out or too much hair makes cup go above water line.  If cleaned properly and have water they work well to prevent smells.  And it is an easy install for pipes that do not have any trap.

7 hours ago, Peterw42 said:

A lot of traps in Thailand are bell traps, there is no S/P trap under the floor.

Bell traps can dry out, and often people remove the bell when cleaning etc.

They are and indeed can be retrofitted without too much disturbance but they must be kept clean or the fail to stop smell.  As has already been mentioned, hair is their biggest problems and Thai girls shed plenty of that.

Not read all the comments......but even with traps, if there is no venting you risk sewer gases making their way back out passed the trap.....and as I understand it Thais simply don't go in for venting....???

Could be no seal between the toilet pan and the waste pipe in the floor, or misaligned. Happened to me.

8 hours ago, WEBBYB808 said:

Dont believe or just dont know?

CBA

Many buildings are old, the designers didn’t know better.

Now with newer builds the designers and construction don’t care. 

 

This is why many new builds still don’t have a decent elections (grounding & reversed polarity etc). 

And of course, as you mentioned, P-Trap vs S-Trap....   and then of course, venting to outside. 

 

We moved into a new house a couple of years ago... the toilet in Ground floor guest bathroom wasn’t even plumbed in properly - it was just put there (the holes didn’t even align !)...

 

 

Its the details....  There’s a laughable saying in Thailand... “Farang think too much”... in reality, it is these issues that occur when the cultural norm is not to. 

 

 

1 minute ago, richard_smith237 said:

Many buildings are old, the designers didn’t know better.

Now with newer builds the designers and construction don’t care. 

 

This is why many new builds still don’t have a decent elections (grounding & reversed polarity etc). 

And of course, as you mentioned, P-Trap vs S-Trap....   and then of course, venting to outside. 

 

We moved into a new house a couple of years ago... the toilet in Ground floor guest bathroom wasn’t even plumbed in properly - it was just put there (the holes didn’t even align !)...

 

 

Its the details....  There’s a laughable saying in Thailand... “Farang think too much”... in reality, it is these issues that occur when the cultural norm is not to. 

 

 

100%......We are due to move in in a couple of weeks.....I 'think' the major items......foundations, roof, walls etc are all okay......but the attention to detail beyond that is just non-existent......I have had to stop the wife going in as there was a risk she was going to turn violent.......I have told her to hold the final payment and then we will go to town on the 'snag list'......basically the builders don't give a flying **** about the quality of their work

Talking of Thai plumbers I remember a farang writing about his house build in Isaan a few years back.  One day he discovered a damp area in a bathroom wall and realised a water pipe concealed under the render must be leaking.  When confronted the builder admitted there was a join in that area and promised its repair.  Later in the day the owner was shocked to notice huge palls of smoke pouring out from behind the house.  He soon discovered the builder had piled a large heap of empty cement bags etc up against the wall and set fire to them.  The builders explanation was that the heat in the wall would soften the glue and reseal the join ending the leak.......no more ploblem!  True story!

Edited April 12, 20224 yr by ThaiFelix

13 hours ago, SheikYabodyline said:

That's about the size of it, and like not installing an earth in the wiring of a house, not having a water trap to the shower waste water to prevent 'blowback' is all about saving money - that, or indolence.

Did you forget that in Thailand electricity and water flow are different to the normal world. 

18 hours ago, wn78 said:

some condo and hotel room I stayed at had sewer smell coming from the bathroom.  It only happened in some rooms,

 Over the years I came up with a temporary solution.

As soon as I notice the problem in hotels or while renting an apartment 

I use the drain plugs (if provided) to block the sink and tub.

If no plugs are available I mold wet  paper to block the air flow until I can find a local hardware supply store. . . If the sink or tub has an upper vent hole I drape something over the openings . There may also be a floor drain that needs to be covered as well.