Level up manhole cover

marsaday · Post: # 114099Post **marsaday** Sun Jul 16, 2017 6:25 pm

I have just laid some new drainage in the drive today.

The chamber base is set to a fall in keeping with the old drainage. Approx 30:1.

I have built up the base using 2 risers. The top riser will need to be cut down about 60mm after the top goes on.

But my chamber is at an angle and this section of drive is level.

How do i get my chamber top in place level with the new block paving which will go down next year hopefully. Currently rejigging drains at mo for an extension round the back.

I haven't filled in the runs and chambers yet as BC need to inspect.

Is it a case of cutting down the top riser at a angle to get it level ?

Post: # 114101Post **seanandruby** Sun Jul 16, 2017 7:32 pm

Chamber should be upright. Yes cut it down to level. You will need to concrete a plinth around the risers about 150ml deep and wide enough to carry the lid so that the lid sits on the concrete plinth? Not the risers as the (assuming they are plastic risers ) risers and base won't take loading over 1.5 ton.

marsaday · Post: # 114102Post **marsaday** Sun Jul 16, 2017 8:17 pm

Ok thanks for that. If i had set it upright would i still have needed to do the concrete plinth ?

The first man hole will be in the garden area, so not on the drive. the second MH is on the drive and could potentially have a car on it in the future. They are only 330mm MH's.

Post: # 114105Post **seanandruby** Mon Jul 17, 2017 7:22 am

Yes 150 concrete. The shallow i c lid takes 3.5 ton depending on make. You might need to upgrade depending on vehicles weight etc:
Best done once, done right. How much out of plumb is it? Will the shite still flow?

marsaday · Post: # 114107Post **marsaday** Mon Jul 17, 2017 9:28 am

The base has been set with the flow of the drain, so it is flowing perfectly with a fall of 10cm over a 3m run to the old 5" clay pipe.

So because the base has been laid at an angle the risers are not level. It is not terrible and this man hole will be in a flower bed area.

The other man hole 3m further back but at the start of the run will be in the drive and the fall is not quite as steep, so levelling up the lid should be easy. This is where i will need the concrete, but the cars do not come up this far anyway as the front door is right next to it and so it would be hard to get in the house if parked at this spot.

Mon Jul 17, 2017 10:28 am

No need for concrete in lanscaped area, just in drive.

rxbren · Post: # 114119Post **rxbren** Mon Jul 17, 2017 5:59 pm

i always install the chambers on a bed of concrete ideally the chambers should be set level a they have a fall built into the chamber, you can trim the riser level but depending on the angle of the riser it may have "grown" in length when its cut if its a foul drain with a seal there is a possiblity of having to use a different lid