Replacing an old cast iron manhole cover
David Chapman
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 - (dcch...@minda.co.uk)
--------------------------------------------------------------------------
Onetap
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.
NT
> 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
Onetap
> 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.
Andy Dingley
> 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.
A.Lee
> 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'.
Matty F
> 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
Stuart Noble
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
Andrew Gabriel
David Chapman <da...@minda.co.uk> 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
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
Michael Chare
news:eRJCeeA$EXgL...@chassis.demon.co.uk...
>
> 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.
>
Make sure that you buy one that is strong enough to support a vehicle. Some
covers are only suitable for pedestrian use.
--
Michael Chare
Andrew Mawson
"Michael Chare" <Munders...@chareDOTorg.uk> wrote in message
news:OpmdnZs9NJmkRx7W...@brightview.co.uk...
the loading is great weld 2" angle irons across the underside
AWEM
David Chapman
> 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.
Grimly Curmudgeon
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 :)
gsgla...@gmail.com
Andrew
which is about 648 by 464.