Replace Concrete Manhole Cover

[pcsparky]

I would like to replace this manhole cover with one that is recessed to accept cut paving or blocks. As you can see the fitting is completely concrete.

Any advice please on removing the concrete and replacing with a recessed metal one.

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[noseall]

first you need to lift the lid out of the frame and see how the frame is fitted to the inspection chamber walls.

it may be a case of removing the concrete surrounding the frame, remove the frame and lid and replace with a recessed one.

if there isn't tolerance for the new lid, and if the manhole is made from brick, it will be possible to remove a course of bricks and deal with the new frame from there.

if the i.c. is prefabricated rings then you will either have to do a lot of digging or hire a grinder.

 

[pcsparky]

Perhaps this will assist in your answer. Thanks very much.

 

[noseall]

that looks like a very shallow i.c.

oh dear.

are you any good at re-building man holes?

 

[Thermo]

is the cover at finished level of the new block paving or is it too high?

 

[noseall]

is the cover at finished level of the new block paving or is it too high?

from a regulations point of veiw, that existing cover is about 2" too high.

 

[Thermo]

if your refering to the dpc then there are ways around it that a bco would accept, providing its not coming any higher, otherwise how are you at rebuilding manholes?

 

[pcsparky]

These monstrosities are all the way around our house, put in about 30 years ago by a builder that built the house for himself. Not exactly sure why there are so many, there are about 8. Tried to get some plans from Water Authority but they don't have any.

This particular one is very proud of the surrounding concrete. In this location I am able to lay flags straight on to the concrete and still be a bit more than 15cm below DPC and below the airbricks.

Not sure what an i.c. is that was mentioned.

The top of the pipe in this photo is 20cm from the gap between the concrete collar and the manhole. It's hard to see on the photos but the collar doesn't look as if it's attached to the manhole just resting on it with a lip.

I was wondering whether it was a simple case of removing the collar and replacing with a new lid and surround/collar. As I say I can build up the surrounding area if necessary with flags, alternatively I don't mind removing the surrounding concrete path and replacing entirely.

Unfortunately my skills end there, I've no idea how to replace an actual manhole.

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[noseall]

so long as the finished level, once paved, is 150mm below dpc and does not in any way stifle the air bricks then maybe you're in luck.

recessed i.c. (inspection chamber) lids are rather deep though, around the 100mm mark. if you think you have the tolerance then go for it.

it is a simple case of hammering up the old lid and frame ane re-bedding the new one. the existing concrete cover is fitted separately to the i.c. ring and is completely removable.

i'm not completely convinced that you have the room to do it though, but my observations are from an office chair!

 

[pcsparky]

Thanks for the advice noseall.

I think you're right, I didn't realise the recessed were that deep. If I was to fit a steel lid would that be less deep?

 

[pcsparky]

Further to my last. I've just found these 45 mm recessed lids with 58mm frames on:

http://www.manholecovers.co.uk/access-covers/mhc-7100-series.html

I should be able to fit one of these I would have thought and fill the recess with flag stone and flag the surrounding area.

Not sure if they're a good price. They're wanting £105 plus delivery for:

750 x 600mm Internal Clear Opening (830 x 680mm across frame) 45mm Deep

 

[noseall]

these frames are designed to take internal floor finishes such as floor screed and tiles etc, and aren't wholly suitable for external paving situations.

the paving type recessed i.c. covers are flat sided and will deal with paving plus bedding.

 

[pcsparky]

I see

I think I'm going to be limited due to depth to a normal steel one. Are the cheap ones in Wickes and B&Q any good or would you advise getting one from a builders merchants or online company such as the one I posted?

I would prefer one thats's not going to rust quickly and would rather pay extra for quality if the DIY stores are no good.

 

[noseall]

our local builders merchant supplies these,http://www.clark-drain.com/

 

[pcsparky]

Thanks for all your help.