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Hi. I own a three storey house. 4 toilets. 3 showers.
Since I moved in a couple of years ago there’s been a recurring (and very mild) sewer odour. Most can’t smell it but I can and it’s coming from the shower traps mostly. And sometimes the kitchen sink. At first I assumed a pipe blockage and went about trying to clear it.
Finally I realised it’s not most likely a blockage but rather the fact that the house has no soil vent! My other neighbours all have one but ours had a big dormer loft extension some years ago and it was clearly removed.
I’m guessing they added an air admittance valve to meet building regs which isn’t visible so it must be built into the walls. Presuming the AAV had malfunctioned I added a new one off the upstairs sink (the highest water point) and hoped all would be well. It wasn’t and I got in a plumber to take a look. He suggested adding more AAVs. Which we did. And it’s still not worked. He thinks it’s probably just too big a system to be vented by small AAVs on the third floor and I’d like to reinstate an outside vent to clear the issue once and for all.
The issue I have is where to put it. The layout of the house is as follows: On the ground floor, I have a visible soil rising from the ground sewer and going up to ceiling height at ground level. It then disappears inside the house. Presumably under floor boards on first floor. There’s then a normal soil to both toilets on first floor and from that point, all other soil pipe is smaller 40mm white pipe. That covers the showers and sinks on first floor and the sinks, showers and toilets on second floor, because we have a saniflow.
Because there’s not a full size soil to top floor level, I’d have to add a full size soil to the extra two storeys and have a roof vent. This would be logistically challenging because it would need to divert around existing dining extensions and aesthetically will look very incongruous given the design of the loft dormer. I’d also have to cut through three separate roof lips.
My questions are therefore:
Does the vent need to be at roof level? Building control seems to stipulate that it must be 900mm from an opening window, but could I theoretically add a vent to the soil at ground roof level provided it was 900mm away. Or would it cause problems given it was so low?
Would it be a problem that the vent was far below the highest water point? Plumber says it wouldn’t be a problem because water can’t go up. And if there was a blockage we’d presumably know about it long before it went to ground roof level?
Are there any other ways to solve the problem? Could we add AAV’s to every sink in the house. Would that make a difference? Again plumber thinks that’s unlikely to cause a problem because of said earlier blockage indicators we would receive.
Many thanks for any help received.
Thanks. Dave.
Since I moved in a couple of years ago there’s been a recurring (and very mild) sewer odour. Most can’t smell it but I can and it’s coming from the shower traps mostly. And sometimes the kitchen sink. At first I assumed a pipe blockage and went about trying to clear it.
Finally I realised it’s not most likely a blockage but rather the fact that the house has no soil vent! My other neighbours all have one but ours had a big dormer loft extension some years ago and it was clearly removed.
I’m guessing they added an air admittance valve to meet building regs which isn’t visible so it must be built into the walls. Presuming the AAV had malfunctioned I added a new one off the upstairs sink (the highest water point) and hoped all would be well. It wasn’t and I got in a plumber to take a look. He suggested adding more AAVs. Which we did. And it’s still not worked. He thinks it’s probably just too big a system to be vented by small AAVs on the third floor and I’d like to reinstate an outside vent to clear the issue once and for all.
The issue I have is where to put it. The layout of the house is as follows: On the ground floor, I have a visible soil rising from the ground sewer and going up to ceiling height at ground level. It then disappears inside the house. Presumably under floor boards on first floor. There’s then a normal soil to both toilets on first floor and from that point, all other soil pipe is smaller 40mm white pipe. That covers the showers and sinks on first floor and the sinks, showers and toilets on second floor, because we have a saniflow.
Because there’s not a full size soil to top floor level, I’d have to add a full size soil to the extra two storeys and have a roof vent. This would be logistically challenging because it would need to divert around existing dining extensions and aesthetically will look very incongruous given the design of the loft dormer. I’d also have to cut through three separate roof lips.
My questions are therefore:
Does the vent need to be at roof level? Building control seems to stipulate that it must be 900mm from an opening window, but could I theoretically add a vent to the soil at ground roof level provided it was 900mm away. Or would it cause problems given it was so low?
Would it be a problem that the vent was far below the highest water point? Plumber says it wouldn’t be a problem because water can’t go up. And if there was a blockage we’d presumably know about it long before it went to ground roof level?
Are there any other ways to solve the problem? Could we add AAV’s to every sink in the house. Would that make a difference? Again plumber thinks that’s unlikely to cause a problem because of said earlier blockage indicators we would receive.
Many thanks for any help received.
Thanks. Dave.
