nasty smell

[Marie]

Help - we appear to have a nasty smell (so my latest renters have texted to tell me), in one of our bedrooms. The room is the one nearest to the septic tank, so I had the tank emptied last week.  The smell went for 36 hours, but then came back again.  The vent pipe from the tank does go up through this room, but we've put so much mastic & expanding foam around the joints, I don't see how anything can escape from there. There are no boggy areas around the tank, and when we were there last weekend, there was no smell outside the house.  According to the builders plans, there shouldn't be any pipes running underneath this room, so what can be causing the smell??

Any ideas or suggestions as to what I should do next? I'm dreading the phone ringing, as the new renters arrive today, and I thought we'd solved the problem when the tank was emptied.

 

Marie

[Nick Trollope]

Is the top of the vent blocked?

If you have mastic'd and foamed the joints, why? Did you have a problem before & has it recurred?

Why does the vent pipe for the FS go through this room, when none of the soil pipes do? Are you sure? What is the floor made of?

 

[Marie]

The top of the vent goes out through the roof, but I haven't been up there to look for a blockage, as we're in the Uk for another week.  The house is only 1 year old, and we did have problems with the vent pipe when the house was new, as the pipe hadn't been sealed properly. We haven't had any problems since then, until this last week.  

I don't know the rationale for putting the pipe in that room, other than it passes through the nearest corner of the house to the septic tank. I just put it down to the mysteries of French plumbing and design!

Neither my husband nor I can think of anything which might be causing the problem - we thought it was just a full tank and the problem would go once it was emptied.

Any other suggestions gratefully received!

 

Marie

[Marie]

p.s forgot to say that the floors are solid concrete, and all the pipes were laid before the slab was poured, in typical new build style.  I can't catagorically state that there aren't any pipes underneath, but the architect's plan for the build shows the pipes going out on the other side of the building, which is where all the plumbing is located.  The idea of a new build was that all the services could be logically placed, with all the plumbing collected together!

 

Marie

[Nick Trollope]

If the house is a year old and the vent stack has leaked before, the can't you get the builder in - it will still be under warranty! (In theory).

I would worry about a design that brought a vent pipe back into the house and didn't "Tee" into the soil pipe run - I can't see the design "logic" in it. Hence my question.

If you have had problems with the vent stack before, then that, I suggest, is where the problem lies now.

 

[Eslier]

Really this is heading into the unknown without any of us having the opportunity to look at the problem. It could easily be nothing to do with the fosse and there could just be some sort of dead animal rotting away somewhere.

I do have a few observations however. Firstly, if your house (and presumably the fosse) is only a year old then there certainly shouldn't have been any need to pump it out providing it has been looked after. Secondly, you talk of putting mastic and expanding foam around the "joints" but I am surprised that there should be a joint where the pipe passes up through the interior. The pipe comes in pretty long lengths and it should have been possible to avoid joints. Thirdly, when your fosse was pumped out, was it filled with a reasonable quantity of water afterwards to provide some coverage for what was soon to pass into it, and did you re-start it with a good dose of Eparcyl or similar. Fourthly, (as has already been raised) have you been treating your fosse with a weekly sachet of Eparcyl - this is especially important in the warmer summer months. With gites it is better to use the weekly treatments rather than the longer lasting stuff as you have no idea what your guests will be putting down the sink or toilets.

[Gyn_Paul]

Is there an air intake pipe anywhere near the room? sometimes the rubber gaskets go (but not usually in so short a time) and let air/gas out as well as air in..... Other possibility... is there a bathroom with an unused shower or bath? In these warm days the water might well have evaporated from the trap.

(clutching at straws here!)

 

p

[Jc]

Surely all new-builds in France must come with a 10-year warranty-mine did but that was 17-years ago!

[Marie]

We have got a 10 year warranty, but the plumber who installed the pipe is on holiday until the end of August, and as we've got renters in until September I would rather do something myself if it's something simple.

As for the air inlet pipe, as far as I am aware, it is outside, but I'll check when we get there on Saturday.  I've got the maintenance technician coming out next week to check that the system is working properly.

I really posted the question in case there was something really obvious we had overlooked in our inexperience of having a septic tank. Thanks for all the suggestions so far.

Marie