New Home, shower smells bad when dry.

[PeterA]

Had a house built 2 years ago by a Western builder. Within days of completion, I noticed one of the bathrooms, the one farthest from the tank  smelled terrible, starting late at night. The builder added a small 1/2 inch pipe off the storage tank for all waste to vent the fumes. Still happens. If not a lot of  water goes down the drain at night, it will smell terrible. The closer of the showers to the tank does not smell, and is rarely used. 

If I pour a bucket of water down the drain, the smell will hold off until the next day.

The two shower drains meet halfway to the tank, so why one and not the other is perplexing. How to solve the problem even more so.

The builder is the last person I want to contact. Any ideas? Digging up the pipes in not doable.

[Artisi]

There is many posts addressing this problem, suggest doing a search and review some of the comments, many comments are useless but in amongst it all is some worthwhile commentary.

 

Possibly a floor drain with water barrier could be the answer. 

 

[rvaviator]

One possibility 

 

Residue water in the pipe - i.e. the pipe does not have a 'fall' all the way from the drain to the tank.

 

I had a similar problem a long time ago - had to rip up the floor. I found that the pipe had a sag in the middle .. water would lay there and after a day or two .. smell would come up from the drain .. Flush with clean water .. would go away .. but always come back ...

[rvaviator]

5 minutes ago, Artisi said:

There is many posts addressing this problem, suggest doing a search and review some of the comments, many comments are useless but in amongst it all is some worthwhile commentary.

 

Possibly a floor drain with water barrier could be the answer. 

 

Yes a water trap on the drain would do the trick ... But my understanding is that they are not used that much in Thailand .....  

Edited January 19, 2020 by rvaviator
add extra info

[matthew777]

You just need to install a proper "P trap" and your smells will go away. 

[rvaviator]

may be worth installing one first .. before digging up everything ...

[Artisi]

4 minutes ago, matthew777 said:

You just need to install a proper "P trap" and your smells will go away. 

Not that easy in a Thai house with every pipe buried in the concrete below floor level. 

[sometimewoodworker]

11 minutes ago, rvaviator said:

Yes a water trap on the drain would do the trick ... But my understanding is that they are not used that much in Thailand .....  

Water traps on showers are standard in all the hotels I have used, bottle traps are the most common on washbasins. However the waste water plumbing is often not vented correctly. This could be one of the faults with the OPs problem 

Edited January 19, 2020 by sometimewoodworker

[Lacessit]

Probably a water trap inserted at the drain point would fix the problem. Cheapest way to do it, unless the OP wants to keep pouring water down twice a day. I'd suggest a cracked pipe or leaking connection in the section from that toilet is resulting in sewer gases coming back. It would explain why the gas return is not instantaneous.

 

"The builder is the last person I want to contact". That's a clue in itself.

 

[rvaviator]

10 minutes ago, sometimewoodworker said:

Water traps on showers are standard in all the hotels I have used, bottle traps are the most common on washbasins. However the waste water plumbing is often not vented correctly. This could be one of the faults with the OPs problem 

Maybe a house builder is a bit more 'relaxed' about things compared with a commercial hotel build.  If I understand the OP correctly .. two showers feed into the same drain .. but only one shower has a smell ..  Would not both smell if the if the venting was not correct ? Appreciate its hard to answer when not having seen the installation .. But something to consider.

[ireckonso]

Quit peeing in the shower.

[rvaviator]

If you are on the ground floor .. Hack up the shower floor and install this type

 

[impulse]

I always poured a little bit of laundry bleach into the drain, followed by a few liters of clean water.  It's a temporary fix, but pretty effective at reducing the smell.

[sometimewoodworker]

37 minutes ago, rvaviator said:

Maybe a house builder is a bit more 'relaxed' about things compared with a commercial hotel build.  If I understand the OP correctly .. two showers feed into the same drain .. but only one shower has a smell ..  Would not both smell if the if the venting was not correct ? Appreciate its hard to answer when not having seen the installation .. But something to consider.

While I didn’t say that it was the problem, there is a scenario in which it could be a cause. The showers that don’t smell could be siphoning the water out of the smelly shower due to inadequate venting.

 

Note I don’t say that this is a cause but it could be.

[Don Chance]

The problem is with the plumbing. It needs to be vented. There needs to a vent that connects to the sewage pipe that leads to day light, above the roof line. It's called a stack vent.

 

The septic tank also needs venting. There needs to be an intake vent and an out take. about 3" in diagmeter.

[BritManToo]

On 1/19/2020 at 8:29 PM, PeterA said:

If I pour a bucket of water down the drain, the smell will hold off until the next day.

The two shower drains meet halfway to the tank, so why one and not the other is perplexing. How to solve the problem even more so.

The little rubber cup under the shower grill is probably either damaged or missing.

When the cup makes a seal to the drain it stops the smell.

In the west we have a 'U bend', in Thailand they have a little rubber cup.

 

Edited January 25, 2020 by BritManToo

[Andrew Dwyer]

4 minutes ago, BritManToo said:

The little rubber cup under the shower grill is probably either damaged or missing.

When the cup makes a seal to the drain it stops the smell.

In the west we have a 'U bend', in Thailand they have a little rubber cup.

 

This would be the first place to look, if the shower is not being used regularly the water will evaporate and smells will appear. Top up with water every 2 or 3 days.

Same goes if you have another drain in the bathroom.

[AhFarangJa]

I appreciate this idea is not a fix, but gets rid of the problem while a permanent solution is found. I took a thin ziplock bag and half filled it with water. When laid over the drain it it supple enough to form a seal over the cover, which stopped smells ( and cockroaches ) coming from the drain. a 7/11 plastic bag will do the same job, but may leak after a while. Just a suggestion.

[rwill]

There are floor drain that block odor and bugs either by holding water or having a flap that closes when water stops running.  You can find them in construction stores, global, Homepro, lazada, etc.  If you get a water one try to find one that holds a decent amount of water so it doesn't evaporate away real quick.  Lots of them have a very small rim that doesn't hold much water.

 

Alternatively get a rigid flat piece of plastic and cover the drain with it when not in use.  You can put something to weight it down if you want.  Some put water bottles on top of the plastic.  

 

[lovelg10]

We use this type of shower drain - very effective. For those floor areas that do not get flooded, we add water every couple of months.
 

[sucit]

I would love to hear more about "the builder is the last person I want to call". He is a foreigner? 

 

Those traps above should stop the smell for 100 baht, although maybe not a long term solution?

[bkk6060]

Probably a dead animal.

Don't they have Roto Rooter here?

[Pdavies99]

On 1/19/2020 at 1:42 PM, Artisi said:

There is many posts addressing this problem, suggest doing a search and review some of the comments, many comments are useless but in amongst it all is some worthwhile commentary.

 

Possibly a floor drain with water barrier could be the answer. 

 

Stupid builders...In Thailand they don't bother having a U bend water trap built in, hence smell..You can buy a water drain part that fits on the outlet very easily.  Also you could fit a exhause vent on the sewer tank ie the type that spin around.

[Kurtf]

You are venting fumes from your sceptic system up through the shower drain. The easiest fix is to fill a ziplock bag with water .seal the bag and place it over the drain.

[GreasyFingers]

5 hours ago, lovelg10 said:

We use this type of shower drain - very effective. For those floor areas that do not get flooded, we add water every couple of months.
 

I have shown my builder that type of drain twice. The tiler was about to install what the builder had bought and I went off my head. The builder had bought a cheap Thai version that did not hold any water and relied on it being clean all of the time.

[Isaanbiker]

Op, tell your gf/wife to stop eating Plaa Raa and the smell is gone. 

[Artisi]

8 hours ago, AhFarangJa said:

I appreciate this idea is not a fix, but gets rid of the problem while a permanent solution is found. I took a thin ziplock bag and half filled it with water. When laid over the drain it it supple enough to form a seal over the cover, which stopped smells ( and cockroaches ) coming from the drain. a 7/11 plastic bag will do the same job, but may leak after a while. Just a suggestion.

Is that a good fix with 7/11 not supplying plastic bags anymore, ????

[brianthainess]

On 1/19/2020 at 8:47 PM, matthew777 said:

You just need to install a proper "P trap" and your smells will go away. 

A  U bend is not needed, the ones fitted in most thai buildings is a top hat drain just found out they are called a p trap sorry.

[Lee4Life]

I had the same problem in a new build two years ago. The odor was the septic venting back up through the drains because no "P" traps were installed.

   I tried the shower drain traps but then found that there was a drain near the toilet that also released the odor.

 

        I dug up the 2" grey water drain just outside the building and installed a P trap in that pipe, that fixed the problem.

[Road Warrior]

rubbish as retire construction director the problem is not venting THERE IS NO TRAP TO BASIN /SHOWER