Sewer smell in bathrooms

Does anyone know of a plumber who does smoke testing in Adelaide and suburbs? A camera snake has revealed nothing wrong, other than soap scum, which we've tried to clear with constantly pouring extra water down overflow drains, showers, basins, and using Actizyme. We've also tried those drain mate things in the overflow pipes, but, while the smell diminishes a bit, it is still there, and the smell continues to come up the showers and basins. Nothing so far has helped clear the smell. I came across a website that said the next thing to try is smoke testing but I haven't found where I can source a plumber who does that in Adelaide. All suggestions welcome.

No one? Any suggestions how to handle the smell? I'm pouring litres of water down each of the downpipes, the showers and basins each day but still the smell is obvious. Would really appreciate some advice.

Every so often we have a bit of a smell from our ensuite. I think ours is due to old terracotta pipe, and algal type growth that's now absorbed to the pipe. It is worse after periods of not being used, or hotter weather (we're not on a slab). I can keep it totally at bay by about a tablespoon of chlorine down the drain every week or so. We don't use any of the taps for a little while after so it has a chance to sit in the terracotta pipe.

Maybe worth a try.

Try some Biowish Plumbers Pre-Treat.

I currently sell it at a substantial discount but I am in Vic.

A smell shouldn't be coming up past the traps though.

Quite often, bad smells are a result of hair dye products adhering to the pipes.


Now...that has me stumped!

Does your grate/cover discolour too ?

I'll see if I can find anyone who can sell me some. Thanks for the suggestion. As you can probably imagine, the smell is certainly upsetting.


No hair dye has been used. Smell started within weeks of moving in. It's a new house.


Please excuse my ignorance. I mean the overflow drains--the pipes that go down into the ground. I really would prefer to continue to know nothing about plumbing.


The ones in the showers do, yes, and the showers are where the smell seems the worst, though it's often hard to tell. Does that tell a story?

I really do appreciate your answers. Thank you.

Reece Plumbing and similar stores should stock it, a box contains 3 sachets but a box usually costs nearly $40. I can post a box if needed, it weighs 350 grams which puts it in the $7.30 lowest parcel (< 500 gm) postage bracket and it would work out cheaper all up.

The source of the smell is a mystery, it shouldn't be the water in the traps as that should be constantly flushed or at least diluted. If there was some rancid organic oil floating on the surface, I could understand it but the camera would have picked that up.


It's a language in itself.

Downpipes actually flow to the stormwater pipe while the grey and black water goes to the sewer pipe.

Beneath each bathroom there should be a trap or s-bend as SaveH2O says with water in it. When you look down the floor wastes in the bathroom can you see water ?
This is how most bathrooms are laid out...
http://i1212.photobucket.com/albums/cc455/stewiesno1/interconnecting-systems_zps9bbec0a1.jpg

The toilets are usually connected downstream of the main floor waste.

http://i1212.photobucket.com/albums/cc455/stewiesno1/Toilet_zpsaa0ba8e6.png

If you have water in both the main trap and the toilet there is little chance of sewer smell coming back up the line ( unless of course the plumber has "forgotten" to install one ).

Stewie

Thanks for the explanations, Stewie D. Yes I can see water in the wastes (referred to incorrectly by me as downpipes and overflow pipes above); yes there is water in the toilet bowls. The plumber who used the snake camera said the trap was in place. So seems like we shouldn't have a smell, but we do. What does one do when "little chance" becomes reality?

We had a chap explain that you can get bacteria in the U pipe which can cause a smell and get to the metal cover and disfigure it.

He suggested these rubber thingos that went into those drains and touched the water. Apparently it creates some sort of balance. Almost like a thin long balloon - dare I say condom ... - which fits into the drain and goes down into the water.

Anyhow - the smell has done and the grates/covers don't discolour anymore. We used everything from gumption to jiff but couldn't get the stuff off.

He also suggested a few (very few) drops of pine-o-clean (or similar) every few weeks if necessary. We haven't done this - and still the smell and stain etc has not come back.

Also - viewtopic.php?f=21&t=72348&p=1254825#p1254825

I'm wondering also that the plumber may have connected one of the bathroom fittings - shower maybe directly to the sewer line rather that through a trap to save time and money. On one of our renos we pulled the plumber up at the rough-in stage for doing exactly that.

Stewie

Thank you.

I'm learning far more about this than I want to. Builder's plumber had installed two of these and I think I can now see why they are not as effective as might have been hoped--the stem is not long enough to reach the water, so there is still a sizeable hole through which the gases can come back up. Grate Seal looks like it might be better because the end of the stem seems to turn once there is no water flowing through it so there would be no hole through which the gases can come back up--will try to see if we can get some of them to try. I like the look of Drain Mate and Drain Fresh but I think our pipes are 80mm, not 100mm.

Also, looking down the waste pipe in the bathroom just now, there seems to be some sort of builder-type stuff in there--interesting that no one has mentioned that to us when they've been checking the problem. And looking down one of the shower pipes, well, it looks pretty much like sewer sludge to me--is it possible they could do that, connect the shower directly to the sewer, and if so, wouldn't that be obvious with the snake camera?

Will let you know what we are able to try and whether we have any success.

In the meantime, if anyone has any more ideas, please do let me know. I am so grateful for all your suggestions, and exceedingly weary with the smell.

Yes, certainly not unheard of...the old 'branch short cut trick' as Max would say.

The annual "Reece Plumbing Disasters" web page is always worth a look (and a laugh), they naturally enough focus on the DIYer but some registered plumbers also do some incredibly stupid things. Let's hope that the plumber with the camera was competent with his inspection.


A modern shower head is deemed a low flow fixture. Unfortunately, the trap is not fully flushed by the low flow as it requires a flow rate in excess of what the shower delivers to achieve this. The best analogy I can give is when somebody tries to flush a toilet by pouring a bucket of water into the bowl and they find that it doesn't flush properly. Pressing the cistern button on the other hand gives an immediate short burst of water that has a sufficient flow rate to instigate a syphonic action...something the shower drain pipe & trap cannot achieve. To make it even simpler, just consider the fact that a shower head flowing at 9 lpm is only 0.15 lps, nowhere near enough to generate syphonics through the trap.

Drainage design for low flow fixtures is archaic.

The "sewer sludge" that you have visualled is probably a percolating collection of skin cells, soap scum and other organic matter that has remained on the surface because it is lighter than water. Remember, most soap is predominately comprised of tallow.

To me from what you described it looks like a broken water seal that allows sewer gasses to come in or alternatively sewer vent in the wall is unfinished or leaking gas and or does not discharge through roof.

If "Smart" wastes are not installed properly they could leak gas

You should get your builder to get "Expert plumber" that specialises in sewer defects to inspect.

Every week I see some incredibly stupid things done by tradies so it pay to check everything

That sounds sensible, SaveH2O. The shower that smells the worst at the moment is the shower that has little use, apart from me pouring water down it every day in an attempt to make sure the pipes don't dry out, so where would the skin and soap sludge be coming from? it's coming up from somewhere, not washing down from someone having an actual shower.

Thanks so much building-expert--two possibilities that we would like investigated. Don't suppose you have a branch over here. What is the best way to check for broken water seal and/or blocked wall vent? Would smoke testing be of any use? And if so, anyone know who does that in Adelaide suburbs?

Unfortunately there is only one of me, they haven't cloned me yet but it's OK, if you ask around you will find a plumber that specialises in this kind of thing and a specialist will know what to look for.
good luck

It might be best if I explain how a toilet trap flushes.

When the cistern (toilet reservoir) releases water, the fast release into the pan causes the other side of the trap to overflow with a sudden velocity that fills (primes) the initially empty pipe (shown as the trapway on Stewie's diagram) and this section of pipe is designed to promote priming. Priming the (vertical) trapway creates a syphon and this draws the water in the pipe downwards as a molecularly bonded mass. This is how the toilet pan is cleared of waste.

The waste pipe's trap would flush the same way if it also had a fast inflow that facilitated priming. As is, any gunk will either stay on the immediate surface or else settle at the bottom of the trap. This matter will eventually flush from the trap as it breaks down and is carried over the weir.

Just to go a bit further for some stark reality (bear with me), your 80 mm waste pipe will have an internal diameter of about 76 mm, giving it a volume of about 4.54 litres per metre (pi x r x r x h). For simplicity, let's say 4.5 litres per metre. If your shower flows at 9 litres per minute (and some of the latest water saver shower heads can be as low as 6 lpm), it would fill a 2 metre length of 80 mm pipe in 1 minute. This means that the velocity of water flowing to the top of the weir overflow as measured in mm per second is 2,000 mm (2 metres) ÷ 60 = 33.33 mm per second. This low velocity is why scum and other matter resists being flushed down the trap and then up the other side.

If you look at the 'grate seals' you linked, you will notice that the vertical pipes are much smaller. This is because a smaller pipe can become 'charged' with the available low flow and this is facilitated by the large initial opening under the grate. Having the bottom of the smaller pipe below the water surface also means that the higher flow velocity will cause turbulence in the bottom of the trap and this helps flush the bottom of the trap. What it doesn't do is flush the water surface albeit there is a minor venturi effect present but the seals are also designed to prevent any odours escaping and this overcomes this deficiency.

I have always shaken my head at these 'bandaids' because the regulations mandate larger pipe sizes yet these products are approved for use even though they present a substantial restriction in the regulation sized pipe! What this means is that although there is an industry recognition of a problem with the poor flushing performance of larger pipes when used with low flow fixtures and a recognition that smaller pipes improve a trap's performance, there is no attempt to just simply design a better performing system and change the regulations. The minimum size of DWV pipe is also 40 mm, another fly in the ointment.

Ok, where does this leave you? First, if your seal does not enter the water, it simply acts as an odour conduit. If you want to use a grate seal, you need one that is the correct length. Did a plumber fit the one you have? Ho hum!

As explained, a grate seal will not flush the top surface but out of sight - out of mind.

Have you looked at the personal products that you are using. Changing to a different soap for example could make the difference.

You need a good product to deodorise the pipes but to give the trap and pipes a really good flush, you need to charge the pipes. You can do this with the basins by filling the basins and then pulling the plug. It is harder to do this with the shower as you need a charged column of water to release but filling the shower base and then releasing a seal over the grate at the same time as the basin plugs are released would be an option.

You could also try attacking the surface crud in the waste pipe by pouring in some Bi-Carb Soda followed by some vinegar. This is what I do at my place every month or two even though my drains don't present a problem.

Hopefully, by understanding just what is happening will make your decisions easier.

Just as an aside SaveH2O and I don't want to hijack the thread but what do you think of the American style toilets? When we were in Hawaii a few years ago I was impressed with them. A smaller bowl at the bottom - maybe 75mm - and when you flush them it is a circular motion of water that creates the syphon effect. They flushed extremely quietly due to the direction of the water entering in comparison to the thunderboxes that we seem to have ( and yes I'm talking about all the brands available here in Australia from cheapies with plastic cisterns up to the fancy pants imported models worth a few grand ).

Stewie

Hi SaveH20 How much are you selling this for. Also is there any benefit to putting this in a water tank to keep clean?

I haven't studied them but they sound interesting. I looked at the older Aussie ones and the early water saver pans a while back now when people (and plumbers) were retrofitting smaller cisterns to older pans...a recipe for failure but I have never done design work in this industry segment.


They are normally about $38-$40 elsewhere for a 3 satchet box, I can post them for $32 all up. It is a run out stock.

The Plumber's Pre-Treat is 100% 0rganic and biodegradable, you mix it in a bucket and wait 5 minutes for activation. It does not mask odours, it removes them.

It is used in traps and drains, not water tanks.

Keeping a water tank clean either refers to removing the sediment layer and/or improving the water quality. Both issues can be addressed by improving the harvesting method currently used and there are threads in the Eco Living sub forum that address these issues. The Davey Acquasafe is a good product for improving water quality but it shouldn't be necessary to use it if all else is ok. http://www.davey.com.au/at-home/whole-h ... ction.html