Stuborn manhole cover

[neiloneil]

I’ve got two manhole drain covers that I need to remove, but just can’t budge them. They are both recessed and have thick flag-stone fitted in them. One type has 4 countersunk screws either (M8 or M10) screwed into holes, which are the only means of lifting the thing. The other also has handles which can be raised up to get a solid grip. I tried lifting the first one with t handles and bars inserted into the holes. They don’t fit too well but I can tell the thing is stuck. The second one won’t budge either, despite having a better grip on it.
HSS will hire a lid lifter for £54, but it says the seal must be broken before using it. So I don’t want to do that. If I could break the seal, I’m sure myself and a helper could lift the thing with no problem.
I’m thinking maybe using box section steel supported on timber bearers either side of the manhole, with threaded bar through into the 8mm or 10mm holes, then either screwing nuts down or driving in wedges to break the seal. I think I have now answered my own question which was going to be “how can I break the seal?”. I’ll try it anyhow and report back.

Id be interested in your comments, as i didn't find any diy solutions on the web. How do you guys do it?

 

[noseall]

With enough power or leverage you will shift the lid, only problem is the frame will come with it!

It sounds drastic, but the only successful way is to remove the material out of the lid and bolster chisel around the frame/lid slot until it is free.

Put some grease around the edges of the lid before you put it back.

 

[HERTS P&D]

Use a club hammer and bolster around the edge, then use a crow bar to lever the edge up.
It will come up, it will just take time (and sweat)

Andy

 

[r896neo]

They are often been left in place by lazy contractors as the paving was jointed and so can be very troublesome

A combination of power washer and hoking with a pointing trowel will help blast some of the crud out that is holding them in follwed by some washing up liquid poured into the rim.

A recessed cover is so thick its very hard to try and lever it out with brute force without really destroying the paving around and inside the cover.

Bare in mind a recessed cover alone will cost 50 quid so hiring a lifter may not be a bad idea if your going to destroy the cover trying to lift it.

 

[neiloneil]

Turns out the 8mm threads are not in the re-moveable cover, but are in the fixed frame beneath. This now seems bloody obvious, as they obviously provide a lock-seal against back pressure from the sewer system during flood events etc.
I did free the covers up easily enough in the end though. I broke out some of the mortar and crud from the seal with a screwdriver, then used an old panel saw to totally remove the debris and free up the cover.
I then used two x 1 Meter lengths of 12mm threaded bar in two adjacent holes (not screwed in ). By pulling the two bars together, they locked up nicely in the holes and it was then easy enough to lift out by myself. With one edge of the cover up, I slid another bar beneath then just rolled the heavy cover clear by using the other pair of lifting holes.

Caution
Watch your back when lifting these things. make sure the seal is broke first with small movements . Nearly did myself some mischief.