Help - Cant lift recessed manhole cover

[alp078]

Hi

I need to investigate a blocked drain to see if I can resolve it myself before resorting to calling in a pro, but I can't lift the recessed cover in my garden. I can access the lifting keys no problem, but it won't budge. Two of us have tried lifting and the weight (even with slabs inset) should be quite manageable.

I am assuming that possibly some sand/cement mix or other debris has bonded the tray to the rubber seal. I have tried to seperate the seal by running a fine blade right around the edge, have tapped vigorously all over with a rubber mallet to to try and loosed things up and nothing seems to be working. My next thought is to resort to getting the angle grinder out and cutting the slabs in the tray so I can lever them out.

Anyone have any ideas/advice. I am concerned at damaging the tray/seal and want to avoid shelling out on hiring a hydraulic lifter.

Thanks
Alp

 

[wavetrain]

Is it one of those covers that has block paving inside? If so, remove the paving blocks from it and try again.

 

[alp078]

it is, but they are not loose set, they are cemented in - hence the need to get the angle grinder out to run through the joins and try to level them up.

Looks like this might be the best thing to try next.

Cheers

 

[wavetrain]

I only raised this point, as once I tried, and failed to lift one of those covers. It may be that the cover becomes jammed by sand etc getting lodged. Then, with the bricks in the cover, it is largely incompressible. The result - very difficult to lift by humans.

If you are handy, you could fabricate a hook/lever that may lift it?

You could also try hitting it with a club hammer to shake it up a tad and see if that helps?

 

[^woody^]

Spray some WD 40 around the joint between frame and cover.

You also need to lift this vertically, so may need special manhole keys (or a bent bit of metal) rather than a shovel down the side of the frame

When you put the lid back, grease the side of the frame first

 

[mctav]

My driveway cover got stuck recently, after much wrestling I had to knock a screwdriver and a chisel down between the lid and the frame to lever the one end up. Once the seal broke I managed to lift the cover out, I did knock the sides of the frame about though.

 

[alp078]

Cheers guys, looks like i will have to try a strong arm approach and try to get something in between the seal and tray edge to lever it up. Feels stuck fast though, so not sure how successful i'll be. I've give a good spray with WD40 which should have had time to work by now.

Fingers crossed.

 

[meadowhog]

I had a similar problem with an old 2" thick cast iron jobby over a big manhole. After spending a day with a hammer and broken 1" hacksaw blade I managed to clear out most of the rust. I then dropped in a couple of 16mm nuts into the key holes. i used two so they would jam each other in. Then I used a thick bar with hole in it and layed over the manhole cover so the hole lined up with one of the nuts. I then fitted a bolt through the bar and into one of the nuts. The bar over hung the cover by about 6" and I managed to get a 5 ton machine jack under the bar. Then hanging onto the end of a weight lifting bar used as a lever, the cover slowly came up.

Maybe something like this would work. I doubt you need that kind of power but a car jack or long lever would probably work.

 

[DrNP]

Had this same problem recently.
New block paving driveway was laid last year. It has two Clark-Drain oblong recessed covers with cemented -in block paving inside each tray. Unfortunately the paver completed the driveway by using a vibratory plate to force kiln-sand between the paving blocks. I now realise that the Clark-Drain design is not sealed against sand impaction between the polypropylene casing and the recessed steel cover. .

 

[Si_]

I lifted my two with a 10in Stanley claw bar to create a gap big enough for a thin utility bar. I wish I hadn't, it's horrible down there.

 

[DrNP]

My solution to the jammed recessed block paving covers was as follows.
1. Find an old thin steel kitchen knife (about 9" blade length) that will fit between cover and casing. Grind a hook feature at the pointed end.
2. Gradually work round the tray with the knife lifting out sand from the groove (a hosed vacuum cleaner can be very useful here). Keep doing this very laborious job until ...
3. You can get one end of the tray to lift slightly using a crow-bar (or similar) under the in-built tee-handle at that end of the tray. Be careful not to over-load the handle (mine had a 60kg lift- limit) otherwise it could snap off.
4. Once enough sand has been removed ... lift the tray.
5. Clean-out the polypropylene casing and remove all sand from the sides of the metal tray.
6. Lightly coat inside of casing and outer edge of tray with a suitable grease (I used automotive CV Joint grease).
7. Replace tray into casing.
8. Finally, fill narrow gap between tray and casing with grease. I used a medical syringe (without the needle of course) to run a thin bead of grease into the gap.
This method works if you have enough time available for slowly getting most of the the out with a hook-knife. If speed is required, there is a danger of breaking the lifting handles or damaging the surround block paving!
Hope this helps ...

 

[DrNP]

Sorry, typo on last msg. Should read ...
"This method works if you have enough time available for slowly getting most of the kiln-sand out with a hook-knife."

 

[HERTS P&D]

15 year old thread.

Andy

 

[Si_]

If it's particularly stubborn he could still be struggling.