Is it possible to reduce the size of a manhole cover?

[Anotherbrightidea]

Hello,

As my user name may suggest, I have lots of really good ideas however no reality if they are possible. (Yes, I'm a girl!!)

This time I may have stumped even the most experienced tradesmen.

I have a 600 x 450 internal manhole (really annoying) and want to reduce it to a 450 x 450.

My query... is there a product out there that reduces the size of a manhole cover. Perhaps a smaller frame that sits inside existing frame?

I really hope some one can help. It's a must do!!

Would very much appreciate any advice on how to solve this problem, please don't reply with "It's not possible!!"

Many thanks in advance
"Another bright idea"

 

[bernardgreen]

(Yes, I'm a girl!!)

Not a problem

Perhaps a smaller frame that sits inside existing frame?

That could become a problem.

Reducing the size of the inspection cover ( calling it a manhole is so sexist ) might make it impossible to get drain rods into the drains at the bottom of the chamber when a blockage has to be cleared.

 

[Anotherbrightidea]

Morning Bernard,

I read an article regards to 'man'hole covers just yesterday - in the US they are now called maintenance covers, keeping initial letters the same (apparently saving thousands on signage) and staying politically correct.

I understand what you're saying, although 450 x 450 are available to buy so I'm presuming they're are fit for purpose - 450 is fairly slim but rods are bendy.

Thank you for your reply

 

[bernardgreen]

Even though the rods are bendy if the chamber is a deep chamber then the angle at which the rod meets the bottom of the chamber may be too close to vertical for the rod to be made to bend into the pipe.

 

[Anotherbrightidea]

If I lay on the floor, I'm not far off touching the bottom with my fingers (standard arm length)

I haven't actually carried this out, I'm guessing. If there was a £5 down there it wouldn't be there long!

 

[bernardgreen]

If there was a £5 down there it wouldn't be there long!

It would go at the first flush

 

[HERTS P&D]

Is it worth the trouble for 6 inches?

Andy

 

[Anotherbrightidea]

Yes, as I would like to move a wall. Still hopeful.

 

[Mikefromlondon]

I had to do that, but it was not a wall, it was the garden fence where my neighbors manhole was protruding into my boundary by about 4 " so I removed his existing frame, and a bit of chopping top part of the manhole, re-plastered the frame into new location without moving the actual manhole, so in other words the cover was misaligned to the manhole by about 4", and at the other exposed end I placed a concrete lintel and cemented that in, above this lintel is the center line of my garden fence and the gravel boards, so offsetting the top cover leaving the manhole as is, made it still fully accessible.

 

[^woody^]

You take the frame off, knock a course of bricks off one end of the opening and 150mm of each adjacent side, span three 65mm concrete lintels across, polythene and then screed on top, and your smaller frame goes over the reduced opening.

 

[tomfe]

Is it worth the trouble for 6 inches?

6 inches!!
I'd be lucky with 4.

 

[John D v2.0]

Well, there are enough inspection chambers concreted over in the world, if it's really a must do, one more wouldn't hurt. Just make sure you keep your dynorod membership up to date.
An internal chamber really must be a stinker, what would you do if it was blocked? Imagine opening that up indoorsit was bad enough when our outdoor one blocked.
If it was me and it was a must do I'd find a way to have it outside, so I could rod it one way or another.
Can you draw a floor plan of your house showing all the waste producing appliances and any man holes including which directions the pipes go. Maybe theres a simple solution someone can think to do away with it for ever.