New SVP to existing clay drain

[STEVENk]

Looking for some advice on the best way to connect a new SVP to a 9'' clay drainage run. Planning on using a p-trap below ground with inspection chamber for access but wasn't sure if its best to break out a section of the 9'' run an insert a t piece or if its possible to saddle onto clay pipe? - whats best practice?

... We are getting the trades in to do the work but need to show drainage on drawings for the warrant,

Cheers

 

[Nige F]

To me it sounds odd having a trap @ the bottom of a SVP - also 9 inch clay ? Tee piece would need a manhole Maybe a drawing of what you propose would help

 

[STEVENk]

To me it sounds odd having a trap @ the bottom of a SVP - also 9 inch clay ? Tee piece would need a manhole Maybe a drawing of what you propose would help

I should maybe re-word my OP to - can someone advise how to connect to a new plastic SVP to existing 9'' clay drainage pipe? - I'm not sure what the right methods of doing this are so any guidance of what I could present to building control would help, Thanks

 

[Nige F]

You'll need a manhole (plastic) diameter depends on the depth of the drain. the pipe run is cut and the manhole inserted using flexible band connectors. The SVP connects into a side branch, with a long radius rest bend at the bottom of the stack. Have a look at www.pavingexpert.com loads of illustrations in the drainage section there. Hope this helps come back here as much as you like.

 

[STEVENk]

I was thinking of something like this with a rodding point above ground, then use a saddle connection to existing drainage pipe - but was unsure if the saddle connection would require further access for rodding? - there is existing access around 3-4 meters from where the new saddle joint would be made.

any alternative solutions would be great

 

[Nige F]

Posting @ the same time - I'm not sure about the saddle - others will probably know.

 

[STEVENk]

Posting @ the same time - I'm not sure about the saddle - others will probably know.

Yeah just noticed your reply as i posted - here's a really crude sketch of whats going on (its an old property circa 1850 - with combined drain)

 

[Nige F]

I would imagine the RWP's shown with access covers have traps to stop smells going up them. I see now that there is no existing SVP. The drain just serves downstairs WC etc. Joining and going to a Buchan trap is all correct for the period. I have to say I've not seen 9 inch (stoneware ) pipe - could it be 6 inch bore ( I presume you're measuring the O.D. Cutting in a plastic manhole now seems the best way.

 

[STEVENk]

I would imagine the RWP's shown with access covers have traps to stop smells going up them. I see now that there is no existing SVP. The drain just serves downstairs WC etc. Joining and going to a Buchan trap is all correct for the period. I have to say I've not seen 9 inch (stoneware ) pipe - could it be 6 inch bore ( I presume you're measuring the O.D. Cutting in a plastic manhole now seems the best way.

Yeah was OD measure so id imagine its likely to be 6in bore now you mention it, if using a manhole what sort of sizing do you think would be suitable? Drains prib about 1m below ground where new svp will connect, is there any particular way to connect onto this type of pipe when using the manhole? Im planning on noting connections on a schematic with the warrant but just trying to work out what i may need to show depending on report back

 

[Hugh Jaleak]

If its a 6" drain, you'll get away with a plastic chamber, anything bigger and you'll be looking at building one yourself. Assuming existing drain is salt glazed stoneware, you'll need to cut a section out, and join to a plastic stub fitted to the through channel on the chamber base. Your 110mm connection can use the appropriate side connection(s) as required. Nige F. has already given you a link, the main page you need is: http://www.pavingexpert.com/drain15.htm

Assuming it is 6", a saddle is a non starter, either a junction or chamber needs to be fitted, chamber would probably be the required method I suspect. At 1m depth, a 450mm diameter chamber will be ok. You'll need a long radius bend at the foot of a stack, traps are purely for gullies. Looking at the diagram, you'll probably need to fit a chamber where the WC'/SVP's join onto the runs. You cant have a blind run to a WC, that you are unable to get rods or jetting hose in to clear if it blocks. If the pipework is reasonably shallow at these points, shallow access chambers can be used. Rainwater will need to be discharged into trapped gullies, the 'Bottle' type gullies are probably superior, and offer rodding access downstream so can be connected to the main runs blind.

Be minded that the existing drain is likely the Water Company's asset, and you will require their permission to work on it.

 

[STEVENk]

If its a 6" drain, you'll get away with a plastic chamber, anything bigger and you'll be looking at building one yourself. Assuming existing drain is salt glazed stoneware, you'll need to cut a section out, and join to a plastic stub fitted to the through channel on the chamber base. Your 110mm connection can use the appropriate side connection(s) as required. Nige F. has already given you a link, the main page you need is: http://www.pavingexpert.com/drain15.htm

Assuming it is 6", a saddle is a non starter, either a junction or chamber needs to be fitted, chamber would probably be the required method I suspect. At 1m depth, a 450mm diameter chamber will be ok. You'll need a long radius bend at the foot of a stack, traps are purely for gullies. Looking at the diagram, you'll probably need to fit a chamber where the WC'/SVP's join onto the runs. You cant have a blind run to a WC, that you are unable to get rods or jetting hose in to clear if it blocks. If the pipework is reasonably shallow at these points, shallow access chambers can be used. Rainwater will need to be discharged into trapped gullies, the 'Bottle' type gullies are probably superior, and offer rodding access downstream so can be connected to the main runs blind.

Be minded that the existing drain is likely the Water Company's asset, and you will require their permission to work on it.

Thanks for this, so basically break out a section of the existing pipe and add in a new section that connects the new soil pipe and has a rodding point that can be accessed via a plastic chamber. The rwps are already connected via ptraps/or bottle traps and we shouldn't be touching these.

As far as im aware - the water company don't own this run until it passes on through the buchan trap onto the street side

Thanks for all your help guys

 

[Nige F]

For example a Jewson product code DRHSS123 and Flexseal couplings to adapt from the salt glazed to plastic then into the manhole. The SVP will drop, then a long radius rest bend, then into a connection on the manhole at an angle in the direction of the flow - not the 90 degree one, because if the SVP is close to the manhole then the water/waste can jump up and stick to the opposite side ! PS good advice as usual from Hugh - I was watching Corrie with my message half typed

 

[Hugh Jaleak]

Can you clarify if it's just your property using this drain, or are there others connected? 6" is extremely unusual for a single property, 4" can happily cope with half a dozen homes. Is your sketch a plan view, if so it'll make it easier to suggest what access is need at what point.