Level invert access chamber - am I missing something?

[VDubDan]

The drains at my house are really high (For whatever reason, 1930s build, doubt they gave a crap) as such I've always been constrained. I only juuust about got the fall I needed when I extended them for my extension.

Problem is, I want to insert an access chamber as I'm rejigging a few things and adding some additional drains for a patio.

It seems I want a "Level invert" chamber, so i can just splice it in with the existing fall of the run but I can only find one or two expensive ones on random websites.

Am I missing a technique, or piece of terminology?

 

[DAZB]

This is not bad pricewise.....

Level Invert 4-Way Chamber Base 330mm W x 215mm H

330mm Level Invert 4-Way Chamber Base

www.plasticdrainage.co.uk

or search for Shallow Access Inspection Chamber but this is probably as shallow as you will get.

 

[noseall]

The drains at my house are really high (For whatever reason, 1930s build, doubt they gave a crap) as such I've always been constrained. I only juuust about got the fall I needed when I extended them for my extension.

Problem is, I want to insert an access chamber as I'm rejigging a few things and adding some additional drains for a patio.

It seems I want a "Level invert" chamber, so i can just splice it in with the existing fall of the run but I can only find one or two expensive ones on random websites.

Am I missing a technique, or piece of terminology?

Most plastic chamber bottoms have the through channel at the lowest point in the configuration and the accompanying inlets are usually set higher. It has caused us issues in the past too.

 

[VDubDan]

This is not bad pricewise.....

Level Invert 4-Way Chamber Base 330mm W x 215mm H

330mm Level Invert 4-Way Chamber Base

www.plasticdrainage.co.uk

or search for Shallow Access Inspection Chamber but this is probably as shallow as you will get.

Great find, cheers - yes, that looks like it'd do the job

 

[VDubDan]

Thanks @noseall , glad it's not just me. Wasn't even something i gave consideration to til I went to buy one.

 

[Ivor Windybottom]

They're a good problem-solver but not ideal for raw sewage, as the "solids" can expand as it slows down within the wider funnel-shaped centre and get a bit reluctant to carry on downhill.

Also any "matter" has the abillity to flow up the other inlets from the surge of a flush and sit around there, not so good if one of them is a vent pipe.

With a standard one, if the toilet is on the centre pipe then it should all get cleared every time it gets flushed.

If there's a way of avoiding one, even with a fair bit of work, then it's probably a good idea.

 

[VDubDan]

They're a good problem-solver but not ideal for raw sewage, as the "solids" can expand as it slows down within the wider funnel-shaped centre and get a bit reluctant to carry on downhill.

Also any "matter" has the abillity to flow up the other inlets from the surge of a flush and sit around there, not so good if one of them is a vent pipe.

With a standard one, if the toilet is on the centre pipe then it should all get cleared every time it gets flushed.

If there's a way of avoiding one, even with a fair bit of work, then it's probably a good idea.

Hmm, thanks Ivor - I thought I was doing the right thing by putting one in but perhaps not.

I don't *have* to put one in. Basically, I have a run of 110mm plastic connecting to the existing clay. On my current run of plastic I have 1 toilet, 2x gullies (plus a downpipe), and r odding point all coming in on T junctions.

It's been in a few years with no issues that I've noticed, anyway. but as I was about to add in some extra gullies and then finally permanently bury it under a patio I thought maybe I should put something in.

 

[noseall]

I thought I was doing the right thing by putting one in

It'll be fine, no dramas. It's how we used to build them in t' old days.

 

[VDubDan]

It'll be fine, no dramas. It's how we used to build them in t' old days.

Sorry mate, you mean it'll be fine to put one in?

 

[noseall]

Sorry mate, you mean it'll be fine to put one in?

Yes

 

[Ivor Windybottom]

I've got one, that I fitted. It works, but it's far less than ideal. For the reasons I stated, I'd plan to avoid it if I could turn back time. There's a reason they're hard to get hold of - most people don't use them these days, for good reasons.

 

[noseall]

I've got one, that I fitted. It works, but it's far less than ideal. For the reasons I stated, I'd plan to avoid it if I could turn back time. There's a reason they're hard to get hold of - most people don't use them these days, for good reasons.

"matter" still ends up in the redundant channels, even with raised inlets.And Its certainly not a reason for not fitting one, lol. Especially when falls are at a premium.

 

[noseall]

Sorry mate, you mean it'll be fine to put one in?

You need to prioritise falls over any other irrelevant issues.
Get it fitted.

 

[Ivor Windybottom]

Another stupid DIYNot keyboard war!

Given a choice between minimal gradient and a standard chamber OR greater gradient and a level invert chamber I'd choose the former, it will be much more reliable and more hygienic than the latter.

A standard chamber gets fully cleared every time the main channel is used, guaranteed. A level one doesn't. The side branches of a level chamber will deposit into the opposite side branches, they don't with a standard one. Stuff (e.g. bog roll) can swell and hang about in the wider area in the centre of a level chamber, it can't in a standard one, as it's the same width all the way.

Sometimes there isn't a right or wrong answer, however certain some think they are. It's a question of judgement. I've got one and have minimal gradient. If I was starting again I'd probably use a standard one and make everything downstream lower. It's a private system that discharges to a watercourse so I could have done this, it would have been more work but IMO would have been a better idea.

 

[VDubDan]

The problem @Ivor Windybottom is I've got no room to manouvre. I'm spliced into a clay pipe which then runs under a pre-existing garage/drive, so I'm stuck at that depth which is already very shallow.

Then the "high" side to speak is already in place, which is my extension, but I already got as much fall as I could there without being at basically ground level (obviously had it to get it through the founds, and under a lintel, before it'd be on show)

So my falls are my falls, basically. I just need to get this extra stuff spliced in