Ventilation pipe from new toilet directly outside bedroom window?

[BlogOnTheTyne]

Can any one advise me please. My plumber has put a ventilation pipe from a new toilet room (which has no windows) to come out just outside of a bedroom window on a flat roof. This presumably means that any smells and also moisture from this new room will come directly into the bedroom and also increase dampness risk to the flat roof and the bedroom?

It doesn't look as if it's in the right place, to me and I've never seen one sited there before on other houses - as they usually have a tall pipe that curves away from the house and above the line of the roof.

Does anyone know if this is a) allowed by building regulations? b) will cause smells in the bedroom when the window is open and c) will cause a problem with damp to the flat roof and into the bedroom?

So far the builders are saying that it's fine and they'll 'cap it' and it won't cause smells and there was nowhere else to put it. Am I being fobbed off?

is it a duct from an extractor fan, or is it the top of the soil pipe?

does it go through the wall, or through the flat roof?

We had our soil pipe from our bathroom rerouted when we had some building work done, and it went up to just above top of a bedroom window (next to it, not across it!). Building Regs Inspector came out and made builder increase length of pipe so it vents further away from window. Check with your Building regs inspector. But even if it's allowed, if you don't like it there then ask your builder to change it.

PigletJohn, I'm pretty sure it's the top pf the soil pipe but as there's a new shower room next door too, I can't be 100% sure. The builders there today weren't sure either (plumber had left by then) and main builder director - who I called on the phone - just mumbled something about it being OK and they'd cap it.

It goes through the ceilng of the new toilet room - and straight up through the flat roof, not through a wall. In fact, as there's one pipe hole in the new toilet room ceiling and another one in the adjacent room - the new shower room, then I don't know which one is going into the roof pipe....surely it can't be both, as one would need to go at an angle....I'm pretty sure that where it come out in the flat roof is the area directly above the new toilet.

The builder on the phone mumbled about not needing/wanting to change it now as it'd mean another hole in my roof. He said where else could it go? I suggested it could bend out at an angle and then go above the line of the flat roof - further up and away from the bedroom window. He mumbled something about it needing to go straight up.

I think he thinks he's reassured me and they'll leave it and tomorrow more works will be done in there which will make it harder to change things - in fact it may already be tricky now, as the ceilings and walls were plastered today...

I'd like to come back to him tomorrow with some specific questions or some specific information. Any further ideas?

if it goes up through the roof, where is this window you mention?

Extractor fans are usually mounted on a wall just below the ceiling, and vent through a horizontal duct horizontally immediately behind the fan. It is very rare to vent them through a roof unless the room has no external walls.

Soil pipes in modern houses are most often in a duct in the corner of the bathroom near the WC, and a sloping pipe runs from the back of the WC into the soil pipe. there will usually be a duct in the room beneath which will be boxed in, for this reason the kitchen in a modern house is usually beneath the bathroom so the sink waste can connect to the same stack.

It goes through a flat roof which is straight outside a bedroom window but lower than the main house roof which slopes either side of that small area of flat roof. The bedroom window is about 3 to 4 foot away from the pipe in the flat roof.

The new toilet room (in a garage conversion) is adjacent to an outside wall and the new shower room is adjacent to the toilet room but with no outside wall and within the garage conversion (which is effectively a living room with separate toilet sink room and separate to that, a shower room. Neither the toilet or shower room have a window in them. I think that the shower extractor fan must be being directed into a now plastered over pipe that then leads into the toilet room, that then travels straight up to the flat roof above.

The waste pipe for the toilet/sewers is nothing to do with this of course and runs down into the ground to connect to the drains.

I think therefore that the pipe in the flat roof must actually be the exit point for both the extractor fan and also the pipe to dehumidify and get rid of toilet smells! Yuk! and it's right outside Ds bedroom window which is often open!

It cannot be for both the soil pipe and the extractor fan, this is not permitted and would be insanitary.

It might be a shared extractor.

Oh....so what's a soil pipe? I thought that was the sewerage pipe?

There's only one outlet from the flat roof and nothing else that looks like an extractor fan vent in the external wall....

I presume the extractor fan outlet would often come out through a house wall - but the smelly vent thing (is that the soil pipe?) would look like the other 2 from the other 2 toilets in the house - which is what the thing on the flat roof looks like - a big pipe thing that, in the case of the other two, goes above the roof line and well away from any windows.

I vaguely remember discussing the plans with the project manager and builders at the start and them saying something like, "the vent from the shower can go up and then along and join the toilet one and go out through the same external opening"...

Would that have been a conversation about the extractor fan only or both this and the toilet 'soil pipe'?

Can I just get really clear about a soil pipe? Is this the big pipe that you see above the roof line from toilets, that gets rid of toilet smells and looks like a big drainpipe - but facing upwards? That's what the one coming out of the flat roof looks like but it has this plastic grey 'cap' on it.

I presume you are talking about your soil and vent pipe.

The regs require them to terminate at least 900mm above any window within 3m.

If this isn't possible, you could have an air admittance valve (known commonly as a Durgo) if you have a SVP at the head of the run. Durgo valves allow air in, but not smells out.

"a tall pipe that curves away from the house and above the line of the roof." is the top of the soil pipe. It is vented to the open air to prevent pressure or suction being possible in the drains. It normally vents just above ceilings of the top floor.

The pipe you are describing is probably for the extractors or ventilation of the rooms. The same size pipe is used for both. If it has a plastic mushroom on the top that will be to keep rain and birds out, it will also diffuse the flow of air. Air blown out from an extractor is not very damp or very smelly, and will diffuse into the atmsophere almost immediately. It will I should think be slightly less of a nuisance than the air in a house that does not have an extractor. Incidentally, natural convection will tend to draw steam from a bathroom up a vertical duct even without a fan.

If you were seriously concerned you could have the ventilation duct extended vertically or horizontally to discharge in a different position, but it would need to be well-supported to prevent it moving in the wind, and might be unsightly. It is undesirable to fix brackets to roofs as it encourages leaks

No
Yes
No

Maybe you should tell them to Just Stop and get a building inspector out to look at it.

Puffy shirt, I'm not now sure if it's the soil and vent pipe in the light of Piglet John's follow on post. If it IS, then they've sited it incorrectly. If it isn't, and is just for the extractor fans, then from what you say, Piglet John, it sounds like it's OK to be where it is....and now the builders are going to think I'm a pain in the neck and causing a fuss over nothing.....

They're supposed to come and view it tomorrow and clarify things but I feel I know a bit more now about what I'm talking about. Thank you.

Sorry to come back to this thread but since I posted, I've clarified that it's a vent pipe and shouldn't be an issue, however...........

Today, the actually soil stack has now been erected at the edge of this flat roof, ending just on a line with the bedroom window - so it's further away than the vent pipe, which is within the middle of this flat roof - but as the flat roof isn't very wide, the new soil stack is very very close to the window.

I asked the plumber about it and said I wasn't sure if this would meet building regs. and he said he hadn't realised it might be a problem and didn't know but would look it up.

I also said what about if we sell the house and new buyers don't like the idea of the soil stack peeping over the flat roof outside the bedroom window nor the big vent pipe plonked in the middle of the flat roof, obscuring the view. Finally I said that my son who sleeps in this room wouldn't be happy about about the newly erected soil stack as I'd assured him that the other monstrosity was just a vent pipe and not a soil stack.

I said to the plumber that from what I know, soil stacks are usually sited away from windows and also higher than the main roof line. This one is slightly higher than the flat roof area but much lower than the main roof line.

So I'm back to wondering about the soil stack now - as it went up today and if I need to worry and if it'll cause any issues whilst we live here or if/when I sell the house?

Why wouldn't the plumber himself know more than I do about this?

If it has to be changed, the building company will fight this as they've recently fought back against a different concern and managed to reassure me about that one but I know it's because they understandably don't want to have to take apart recently completed works.

Any further advice please?