Air admittance valve / soil vent pipe

[Carrerahill]

  On 22/01/2019 at 11:36, Tin Soldier said:

sorry to hijack thread, but I guess its relevant question

 

If you are converting a room downstairs to a bathroom of an existing 2 storey property, can you use an aav, given there is another bathroom on the 1st floor above (with vent through the roof? or with it have to have its own soil vent pipe through the roof?

 

it would be joining the existing  foul drains outside the property 

Expand  

If it is going to come out the WC and into the existing vertical soil pipe then you would not need any AAV or vents as the existing one would do all this. 

 

If you are going to tie into another section of the soil pipe not served by upstairs vent then you will need to consider AAV.

 

I have also seen a vent done with a reduction boss, and run out on 50mm, my building control officer is letting me alter the vent to our soil pipe as I said I don't want it going through the roof of our extension, so it is going to be reduced in height then taken at a 90° in the new extension ceiling void, and then go out the side of the extension to a wall vent.

Edited January 22, 2019 by Carrerahill

[Tin Soldier]

yes out of house and into other section of fouls, AAV it is then

[Bitpipe]

Our BCO waived any requirement for external venting as houses either side had SVPs and we're on same sewer run. He said that in new developments, requirement is only 1 in 10 with a SVP.

[Lin]

Sorry;  SVPS ?

[Ed Davies]

SVP = soil vent pipe.

 

Good one for the acronyms and abbreviations page: https://forum.buildhub.org.uk/topic/268-acronyms-abbreviations-glossary-of-common-terms/

 

@ProDave

 

[ProDave]

  On 22/01/2019 at 18:20, Ed Davies said:

SVP = soil vent pipe.

 

Good one for the acronyms and abbreviations page: https://forum.buildhub.org.uk/topic/268-acronyms-abbreviations-glossary-of-common-terms/

 

@ProDave

 

Expand  

Done

[Lin]

I'm just posting this again because it may have got lost now;

 

Any thoughts about durgos that are specified to be  fitted below flood level. Eg Marley 82 SVD3

 

My sloping ceilings are making it hard to site the durgo above flood height so these could be the answer. They could fit in the eaves.

[Jeremy Harris]

Sorry, I don't know anything about these, so I think the best bet is to talk to your BCO and get an opinion, which is what I did when planning the ventilation for our foul drains.

[Gone West]

  On 22/01/2019 at 20:16, Lin said:

I'm just posting this again because it may have got lost now;

 

Any thoughts about durgos that are specified to be  fitted below flood level. Eg Marley 82 SVD3

 

My sloping ceilings are making it hard to site the durgo above flood height so these could be the answer. They could fit in the eaves.

Expand  

I used Floplast AAVs which are "permitted to be used below flood level in locations where the temperature is in the range of -20°C to +60°C". I used them only very slightly higher than flood level but I don't see why they shouldn't be used below flood level as they are designed for that purpose. I think I would be cautious and check with some experimentation before final fitting though.

[Lin]

Thank you JSHarris and PeterStarck for responses.

 

Our BCO has approved durgos and venting the drain. However i am reading a lot of plumbing posts on other fora. Some  plumbers say that if you have only durgos you will have a smelly house. Some also ridicule the competance of BCO's to  recommend such a system.

 

Have your durgos ever let you down ?

Edited January 23, 2019 by Lin

[Jeremy Harris]

We just have an AAV in the eaves space, so up high in the house, not lower down, but it's not presented any problems so far.  I've no idea what the reliability of a low level, flood-resistant  one might be I'm afraid.  The vent in our foul drain is at the treatment plant, which is also above the flood level by about a metre.

[Lin]

regarding "flood level" of the foul drain vent,  you mean the level that lines up with the top of the sink in your bathroom ??

 

[Jeremy Harris]

  On 23/01/2019 at 12:35, Lin said:

regarding "flood level" of the foul drain vent,  you mean the level that lines up with the top of the sink in your bathroom ??

 

Expand  

 

No, the flood level that the EA have declared for the area, the 1:100 year flood risk level.  Our AAV is above the level of the top of any basin.

[Gone West]

  On 23/01/2019 at 12:46, JSHarris said:

 

No, the flood level that the EA have declared for the area, the 1:100 year flood risk level.  Our AAV is above the level of the top of any basin.

Expand  

I think the term 'flood level' in relation to AAVs refers to the basin overflow level.

[Gone West]

  On 23/01/2019 at 11:48, Lin said:

Have your durgos ever let you down ?

Expand  

We have four  AAVs and they are just above basin overflow level and are behind false walls in the bathrooms. We have been using them for nearly a year and, "touch wood", they seem to be fine.

[Nickfromwales]

  On 22/01/2019 at 20:16, Lin said:

My sloping ceilings are making it hard to site the durgo above flood height so these could be the answer. They could fit in the eaves.

Expand  

Another option to extend the site of an AAV is to reduce from the 110mm to 2 x 50mm runs, or 4 x 32mm runs and route the groups of smaller bore pipes where the 110mm cannot be run. Create the opposite adaptation at the AAV end to get back to 110mm and fit the 110mm AAV there. You only need a 34 mm cavity for that. 

[Lin]

  On 24/01/2019 at 05:06, Nickfromwales said:

Another option to extend the site of an AAV is to reduce from the 110mm to 2 x 50mm runs, or 4 x 32mm runs and route the groups of smaller bore pipes where the 110mm cannot be run. Create the opposite adaptation at the AAV end to get back to 110mm and fit the 110mm AAV there. You only need a 34 mm cavity for that. 

Expand  

 

A very creative solution !

[joe90]

I found out that you can reduce a 110mm pipeto 50mm then put a 50mm AAV on it.

[Robin Banks]

I don't mean to hijack the thread either, but I think this post fits into the general flow.

 

We've just moved into the house after having a single storey extension built.

 

I've noticed that there's no soil vent pipe (SVP) anywhere (contrary to the architect's drawings), and nor do there appear to be air intake valves (AIV) fitted internally any place that I can see. I've checked inside the cistern boxing, and there's no sign. Since they need to be accessible for maintenance I can't imagine they would be any place else. The soil pipes for the ensuite and WC aren't tied into the existing stack either since that's upstairs on the other side of the house.

 

I've had a look at Part H of the regs, but it's a bit confusing to the layman - can anyone advise me if one or other of these systems (SVP / AIV) should have been installed to comply with building regs ?

 

Thanks in advance.

 

Rob (long time lurker, first time poster...)

Edited September 24, 2019 by Robin Banks

[joe90]

  On 24/09/2019 at 08:26, Robin Banks said:

having a single storey extension built.

Expand  

 

Did it have building regs approval.?

[Temp]

Typically you are allowed to use AAV on all stacks except the one furthest from the main sewer. Sometimes this rule gets bent a bit so there are houses where the one open vented stack isn't the one furthest from the sewer. 

 

So perhaps the AAV are just well hidden?

 

Also worth looking to see if its in the loft? It must be above the height of the washbasin.

[Robin Banks]

  On 24/09/2019 at 09:11, joe90 said:

 

Did it have building regs approval.?

Expand  

Building Control has signed the work off.

[Robin Banks]

  On 24/09/2019 at 09:44, Temp said:

Typically you are allowed to use AAV on all stacks except the one furthest from the main sewer. Sometimes this rule gets bent a bit so there are houses where the one open vented stack isn't the one furthest from the sewer. 

 

So perhaps the AAV are just well hidden?

 

Also worth looking to see if its in the loft? It must be above the height of the washbasin.

Expand  

I can see where the toilet soil pipes disappear into the poured concrete floor and there's no sign of anything that looks like an AAV. Am I right in thinking that any AAV would need to be at least at the height of the sink overflow ?

[Nickfromwales]

It’s where they rise and continue on to that we need to know. 

Some pics may help. 

Whst we need to know is what happens to the 4” pipe from after it emerges from the ground. 

Please remember that the obligatory vent to atmosphere aka the “stench pipe” ( SVP ) does not have to come from a toilet / other appliance, and can be tee’d off the sewerage system anywhere around your house. The SVP can also be 3” so may look like a down-pipe.   

[Robin Banks]

Thanks for the replies. Have had a good look around and there's definitely no SVP. I'll open the boxing-in of the cisterns and get some pics.