Manhole under fence and under raised planter

[CaptainJack88]

We're having the garden redone, and we've got all the designs down including a raised patio.
Builders have ripped up the old patio, and found a manhole for the sewage that was buried under the old patio, but also partly under the boundary fence (original installation fence from developers 25y ago)

The issue we have is that the manhole, is right in the way of a raised planter. Obviously we can't just go an build the wall on top of it now, but wondering what the regulations actually are?

I've come up with the below solution, but wondering if this is actually allowed. The raised planter is right up against the fence, so the idea here is:
- Concrete lintel to suspend part of the back wall above the manhole (black in render below)
- Build internal wall around it, and then put in some stainless steel tabs
- Put a concrete slab or manufacturer basket into the middle.
- On internal walls, (orange in render) put a lower height brick so that when filled, you can see them, but acts as a retaining wall for the middle section

If access is ever needed, we can clear the middle area, pull out the basket or concrete slab and then were can wiggle the manhole cover off and have access.

Thoughts?

 

[freddiemercurystwin]

Is it a shared sewer or private? Have you lifted the manhole? What is the condition of the pipe run/manhole?

 

[CaptainJack88]

It's shared with the neighbour, active but in pretty good condition. Also can't really move it due to the angles at play and housing alignment (also a ridiculously big job for pretty much zero reward)

 

[freddiemercurystwin]

Just apply some common sense, as long as it can be cleared if neeeds be then go with what you have, seems like a fairly robust/future proof solution.

 

[CaptainJack88]

Yep that's what I was going with. Builder mentioned potential of insurance issues etc if it comes into play etc.

Wasn't sure what the regs were. I just assumed so long as it was accessible by whatevers means you want (other than permanently building over it and digging up) then it was ok

 

[noseall]

Yep that's what I was going with.

You have to bear in mind the thought processes of those that will need to come to clear it. Private drain rodding bods would probably shrug and get on with it. Others (water company fellas) may walk away mumbling about access, H&S, 'not in my remit' or some such. Being under the boundary however, means that access was always going to be a pain, no matter what.

Does the planter really need to envelope the IC? Are you prepared to accept some delay, should the drain block and miserable water company clipboards, refuse to work on it? Has it EVER had the lid off?

 

[CaptainJack88]

You have to bear in mind the thought processes of those that will need to come to clear it. Private drain rodding bods would probably shrug and get on with it. Others (water company fellas) may walk away mumbling about access, H&S, 'not in my remit' or some such. Being under the boundary however, means that access was always going to be a pain, no matter what.

Does the planter really need to envelope the IC? Are you prepared to accept some delay, should the drain block and miserable water company clipboards, refuse to work on it? Has it EVER had the lid off?

The previous owners had a deck over it for 10 years. We moved in, ripped out the old deck boards, framed the joists again and decked over the top (without knowing it was there)

So maybe in 20 years, at least 10, it's never needed access. There's also 2 manholes for the run, about 4 meters away from it that are accessible. This is just because it changes direction

 

[cdbe]

I've seen a few like these with interesting fence/wall access arrangements - but would expect the depth of the IC to be significant - if the invert is a foot deep you'd only really need to get the lid off.

 

[CaptainJack88]

Yep, really doesn't go down far at all. 2ft tops

 

[JohnD]

As I see it, you can either remove the planter and make it accessible now, when you have plenty of time, and builders on site

Or you can do it in an emergency, pitch black in the middle of the night, in a downpour, with sewage gushing up round your ankles.

Which sounds better?

 

[CaptainJack88]

Given the manhole is just for our property and only for services the kitchen, it's not going to be overflowing with sewage any time soon.

We're not making it inaccessible. Just needs a lid removing from the planter to get to it

 

[charliegolf]

To ask the obvious... Why not put a break in the planter and leave the thing open? Better, if the planter is a long run, have two or more breaks to make it less obvious.

 

[CaptainJack88]

To ask the obvious... Why not put a break in the planter and leave the thing open? Better, if the planter is a long run, have two or more breaks to make it less obvious.

There's a bench being built into the front of it, so would look a little odd

 

[JohnD]

@CaptainJack88

What country are you really in?

 

[CaptainJack88]

@CaptainJack88

What country are you really in?

UK - no idea why it's saying USA on my country. Edit: Changed