Replacing an old cast iron manhole cover

Discussion in 'UK DIY' started by David Chapman, Feb 21, 2010.

  1. Hi,

    We have a very old rectangular cast iron manhole cover (approximately
    650mm x 495mm) in our front drive which has just shattered and is now in
    urgent need of replacement.

    The nearest size (in galvanised steel) that seems to be available from
    the local builders merchants is around 600mm x 450mm so it seems likely
    that the old frame will have to be replaced as well with one that is
    large enough to cover the hole plus overlap for fixing.

    I'm posting this in the hope that someone in the NG with experience of
    these problems can suggest any better replacement solutions, or offer
    any hints or tips as to the best way to replace the old manhole
    frame/cover.

    Any constructive comments will be much appreciated.

    ATB - Dave


    --
    David C.Chapman - ()
    --------------------------------------------------------------------------
     
    David Chapman, Feb 21, 2010
    #1
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  2. David Chapman

    Onetap Guest

    On 21 Feb, 17:45, David Chapman <> wrote:

    Hack out old frame, seat new (probably plastic) frame in mortar, make
    good. I had to do a couple after the car wheel went through a paved
    over CI cover. Never done it before, I used the tray type with inset
    paving.
    I've since had a skip lorry parked on one with no ill effects, so it
    must have been adequate.
     
    Onetap, Feb 21, 2010
    #2
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  3. David Chapman

    NT Guest

    On Feb 21, 5:45 pm, David Chapman <> wrote:
    > Hi,
    >
    >    We have a very old rectangular cast iron manhole cover (approximately
    > 650mm x 495mm) in our front drive which has just shattered and is now in
    > urgent need of replacement.
    >
    >    The nearest size (in galvanised steel) that seems to be available from
    > the local builders merchants is around 600mm x 450mm so it seems likely
    > that the old frame will have to be replaced as well with one that is
    > large enough to cover the hole plus overlap for fixing.
    >
    >    I'm posting this in the hope that someone in the NG with experience of
    > these problems can suggest any better replacement solutions, or offer
    > any hints or tips as to the best way to replace the old manhole
    > frame/cover.
    >
    >   Any constructive comments will be much appreciated.
    >
    >    ATB  -  Dave



    Is it possible to drill CI to repair it?


    NT
     
    NT, Feb 21, 2010
    #3
  4. David Chapman

    Onetap Guest

    On 21 Feb, 19:37, NT <> wrote:

    > Is it possible to drill CI to repair it?


    Maybe, but not worth the effort. It's grey cast iron, it has slag
    inclusions in it and it is as brittle as glass. A good crack with a
    hammer will shatter it.
    CI drain covers are only suitable for pedestrian traffic. The drain
    covers used now in roads are ductile (spheroidal graphite) cast iron,
    that was invented in (I think) the late 40s.
    You can weld cast iron apparently; I tried once and after much
    preheating and welding concluded that I couldn't weld it.
     
    Onetap, Feb 21, 2010
    #4
  5. David Chapman

    Andy Dingley Guest

    On 21 Feb, 19:37, NT <> wrote:

    > Is it possible to drill CI to repair it?


    Yes - if it's a simple break into two or three and the load capacity
    isn't required to be too great..

    Easiest is to drill and bolt through with 1/4" mild steel plates
    either side, round head screws with heads uppermost and peen over the
    nuts underneath. Finish with cold galvanise zinc paint and bitumen
    paint.

    Better is to weld it (electric arc), although this is tricky for CI,
    especially large CI.

    If you want someone else to deal with it, there are Metaloc and others
    who do stitched repairs in CI. I'm not sure how they'd do something
    with bending forces on it like this though.
     
    Andy Dingley, Feb 21, 2010
    #5
  6. David Chapman

    A.Lee Guest

    David Chapman <> wrote:

    > Hi,
    >
    > We have a very old rectangular cast iron manhole cover (approximately
    > 650mm x 495mm) in our front drive which has just shattered and is now in
    > urgent need of replacement.
    >
    > The nearest size (in galvanised steel) that seems to be available from
    > the local builders merchants is around 600mm x 450mm so it seems likely
    > that the old frame will have to be replaced as well with one that is
    > large enough to cover the hole plus overlap for fixing.


    It is an easy job to replace the manhole and frame.
    Go to a better builders merchant, they will be able to get you a similar
    sized frame. They come in loads of sizes and weight ratings. Make sure
    you get the weight rating right, otherwise it could collapse again.
    To replace, get a big hammer and chisel, knock out all of the concrete
    around the frame, get out the old frame, then make a 2-3" gap all around
    the outside of the new sized frame.
    Concrete it in, leave a few days,and you can drive over it again.
    Alan.


    --
    To reply by e-mail, change the ' + ' to 'plus'.
     
    A.Lee, Feb 21, 2010
    #6
  7. David Chapman

    Matty F Guest

    On Feb 22, 6:45 am, David Chapman <> wrote:
    > Hi,
    >
    > We have a very old rectangular cast iron manhole cover (approximately
    > 650mm x 495mm) in our front drive which has just shattered and is now in
    > urgent need of replacement.


    I made this smaller cover out of flat steel to replace a cast iron
    cover that was stolen. There's a leg welded under each corner to get
    the height correct.
    http://i50.tinypic.com/29wty52.jpg
     
    Matty F, Feb 22, 2010
    #7
  8. David Chapman

    Stuart Noble Guest

    A.Lee wrote:
    > David Chapman <> wrote:
    >
    >> Hi,
    >>
    >> We have a very old rectangular cast iron manhole cover (approximately
    >> 650mm x 495mm) in our front drive which has just shattered and is now in
    >> urgent need of replacement.
    >>
    >> The nearest size (in galvanised steel) that seems to be available from
    >> the local builders merchants is around 600mm x 450mm so it seems likely
    >> that the old frame will have to be replaced as well with one that is
    >> large enough to cover the hole plus overlap for fixing.

    >
    > It is an easy job to replace the manhole and frame.
    > Go to a better builders merchant, they will be able to get you a similar
    > sized frame. They come in loads of sizes and weight ratings. Make sure
    > you get the weight rating right, otherwise it could collapse again.
    > To replace, get a big hammer and chisel, knock out all of the concrete
    > around the frame, get out the old frame, then make a 2-3" gap all around
    > the outside of the new sized frame.
    > Concrete it in, leave a few days,and you can drive over it again.
    > Alan.
    >
    >


    In my case the new frame was a bit smaller, so I had to lay a course of
    bricks to support one side. If the hole had been deep, I'd have gone for
    the next size up
     
    Stuart Noble, Feb 22, 2010
    #8
  9. In article <eRJCeeA$>,
    David Chapman <> writes:
    >
    > Hi,
    >
    > We have a very old rectangular cast iron manhole cover (approximately
    > 650mm x 495mm) in our front drive which has just shattered and is now in
    > urgent need of replacement.
    >
    > The nearest size (in galvanised steel) that seems to be available from
    > the local builders merchants is around 600mm x 450mm so it seems likely
    > that the old frame will have to be replaced as well with one that is
    > large enough to cover the hole plus overlap for fixing.
    >
    > I'm posting this in the hope that someone in the NG with experience of
    > these problems can suggest any better replacement solutions, or offer
    > any hints or tips as to the best way to replace the old manhole
    > frame/cover.
    >
    > Any constructive comments will be much appreciated.


    I've replaced one which was on a path. Finding one which matches
    the frame is going to be unlikely, particularly if old. As others
    said, buy a replacement frame and cover.

    One thing I would suggest - get a proper cast iron one. I bought
    a pressed steel one (3 tonnes, IIRC), but it went poing-ping
    every time you stepped on it, so I swapped it for a cast iron
    one (7 or 10 tonnes, IIRC). Didn't cost much more, but make sure
    you go to a builders yard with a good stock, and not somewhere
    which just keeps one or two types at inflated prices.

    --
    Andrew Gabriel
    [email address is not usable -- followup in the newsgroup]
     
    Andrew Gabriel, Feb 22, 2010
    #9
  10. David Chapman

    andrew Guest

    Matty F wrote:

    > On Feb 22, 6:45 am, David Chapman <> wrote:
    >> Hi,
    >>
    >> We have a very old rectangular cast iron manhole cover (approximately
    >> 650mm x 495mm) in our front drive which has just shattered and is now in
    >> urgent need of replacement.

    >
    > I made this smaller cover out of flat steel to replace a cast iron
    > cover that was stolen. There's a leg welded under each corner to get
    > the height correct.
    > http://i50.tinypic.com/29wty52.jpg


    I'm quite impressed by the naylor composite covers I have just fitted.
    They're expensive but rated to 12 tonnes and it may be worth the risk of
    buying a 600 x 600 one and cutting one side off.

    AJH
     
    andrew, Feb 22, 2010
    #10

  11. > We have a very old rectangular cast iron manhole cover (approximately
    >650mm x 495mm) in our front drive which has just shattered and is now
    >in urgent need of replacement.


    Many thanks to all those who took the time to reply to my posting and
    offer constructive solutions. Your contributions were much appreciated.

    ATB - Dave

    --
    David C.Chapman - ()
    --------------------------------------------------------------------------
     
    David Chapman, Feb 24, 2010
    #11
  12. We were somewhere around Barstow, on the edge of the desert, when the
    drugs began to take hold. I remember "Andrew Mawson"
    <andrew@no_spam_please_mawson.org.uk> saying something like:

    >Get a piece of 1/4" steel chequer plate cut to fit your hole and if
    >the loading is great weld 2" angle irons across the underside


    Which is the most sensible solution. Iow, just what I'd do :)
     
    Grimly Curmudgeon, Feb 24, 2010
    #12
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