New ground floor svp air admittance

[martysmarty]

Hi guys.

Had a good week getting the groundwork going on the kitchen extension.

We have dug footings, minus removal of a manhole that currently in the way, that leads me to my question! Spoke to BCO and hes give me the go ahead to crack on with drainage so he can inspect both at same time. So tomorrow the old inspection chamber will be gone

I started removing the inspection chamber today and chasing out the clay pipes for the ground floor toilet.

Its an old setup, pan exits into the ground concrete floor, then runs out the building straight into a clay branch, that has got a cast iron pipe venting it.

Id like to change it to exit on the side wall of our house, rather than into the floor, into maybe a stub stack at the side access of my property. Theres an existing run down the side of my house i can cut into from my upstairs wc svp. This goes above roof line.

Heres my plan.

Break into the existing run from upstairs svp with a mini inspection chamber, branch into it, use a rest bend and a stub stack with a vent. I will also need a sink going into it.

Heres the thing. I have a ground floor bathroom window within 3m, so it's going to have to be vented above this window by a minimum of 900mm?

Im not sure if this is a loophole, but my upstairs svp is "before" this new connection. So will that suffice as venting? Technically it should work. And then i could just use an aav indoors or maybe an anti syphon trap.

Also i think i should have posted this in the planning/regs forum?

 

[23vc]

I think so but a diagram would help. Sounds like no trap is going to get emptied if you’ve got the vent upstream. You could use an AAV downstairs

 

[martysmarty]

Cheers 23vc

Il knock something up and take some pictures. Sink waste will need to go out into the stack so i would say an internal aav would be required. But just checking

 

[23vc]

Sink waste will need to go out into the stack so i would say an internal aav would be required

yep it would then

 

[martysmarty]

Added a few pictures.

I managed to remove the old inspection chamber today without cracking the old pipes. So its took me by suprise as i thought i was going to have to replace the lot.

The pipe coming in from the side of the house at the right has a slow sweep bend from my upstairs svp that you can see up my drive. I planned on cutting into it and fitting another stub. Sorta in same place as next doors. Now im not sure. Id have to at least sort a gully for the sink

I need to have a good think what to do next. If im honest i really thought i wouldnt get a good connection to the old incoming pipes.

Downside to keeping it as it is, the pipe is close to the footings and no sink connection

Im going to hook it back up as pictured for now so we got stuff working.

Oh, and yes the couplers are the wrong size!!

I will come back with pics of my other suggestions

 

[martysmarty]

A little oversight. I didnt realise you could not use a side entry into a chamber if the rear entry point of the invert level was not in use for the main run.

As i have it in the picture, both toilets are branched into a side entry. Going to have another look today. If i can rotate my base i can put some 45's on the invert entry and exit and maybe get the stack from the side of the house going into it.

 

[Hugh Jaleak]

If you dig back a bit, can you get the run from the stack on the side of the house in a straight line, past that water box, and then into the main channel with a 45° bend? Gives you the 2 side inlets available then, avoids the need for that Y connection and also provides rodding access along the run back to the stack. Secondly, if this stack goes up to the roofline to vent the system, (which it looks like it does), you wont need another vent on the system. Crack on with the pipework alterations in you pic, the cast vent you speak of can be removed and the downstairs WC can be directly connected to the drain.

Looking at how tight that run is to the building, I have to wonder if you'll get a mini chamber in, and a connection for the downstairs WC. If rodding access is available from the downstream chamber, then that increases your options for connection the WC, (can use a junction instead of a chamber, and perhaps an access bend above ground). Sink can be connected via a boss if there space, are you talking a kitchen sink, or bathroom basin?

 

[martysmarty]

Hi hugh. I fully agree i should have taken it that way looking at it from what you have said. I know what iv opted to do here isnt the best route. But it saves me digging my drive up as its shared and since the clay didnt break iv opted to go this route, i hope it dont bite me in the a** i could still do that if i need to

Iv scrapped the stack idea, iv just put a gully for the sink waste to simply drop down out the wall.

Long term its still possible to remove the old clay up the side of the drive if we really need to but we would have to get neighbours on our side as its shared access.

I still have to remove the cast pipe so i can put the gully in the proper place and change the main run to full plastic. The old clay run that you can see is actually kinked and will be straight. Theres a branch got to be fitted that can be rodded too, at the far end of the run.

Run is about 1:50 so i also need to look at that when i swap the main run. But at least we are back online for now.

Im not quite happy with the connection to the clay for the side stack as its a little off so i need to look at this too. An adjustable bend would be ideal but not sure if i can use it. Iv had to use one already as it was a tiny angle into the ic. Less than 15deg.

 

[martysmarty]

I should of said also, theres one possible issue with the route you have said hugh,

Theres a water main crossing the drive from our neibours side, my worry was that i wont get the fall into the chamber due to this pipe. Admittedly i have not checked to be exactly sure. But i know theres a philmac connection right where the pipe would be as i seen it fitted

 

[Hugh Jaleak]

Run that past BCO before doing anymore, not sure if the 90 turn on the outlet from the chamber will be allowed, he/she may want to see a 45 either side of the main channel.

 

[martysmarty]

Run that past BCO before doing anymore, not sure if the 90 turn on the outlet from the chamber will be allowed, he/she may want to see a 45 either side of the main channel.

Its a fair point and one i was a bit worried about but i thought as it was by the chamber it would be passable.

They need to pass the footings off so i can get advice then. I did have a play with the angles the other day but something always got in the way. That boundary box!

I think if he/she wants it whats the ic turned 45deg then im going to have to get the bb moved too.

I think as you say just wait snd see whats said. Thanks hugh!

 

[martysmarty]

just reporting back.

BCO has been, drainage and footing all passed. i did change my layout before he came and shifted the IC to use the side entry's and took off a 45deg bend on the outlet. scrapping the use of the rear entry and he was happy. pipework up the drive has been left alone till we decide to have the drive done.
its the only bit of clay pipe left on the property so we plan to fit a new SVP stack on the side with new underground smooth bore.