outside man hole / drain cover

23 Apr 2011
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United Kingdom
hiya all, when we moved in we had a lot of decking around the back of our house, a few years on the joists on the step to the decking was rottingsto i decided to take it apart and m but made a slab / concrete step, underneath i found a drain so made a step fit over it with allowing access,

the man hole cover / drain cover is cast and the chamber is plastic, the lid doesnt fit very well as the cast edge of the cover doesnt fit in (iirc its to big forcing you to fit it at an angle, what the previous owner has done they just wiggled it to the best fit, and you can smell it a bit,

do i buy something else and helps it fits, why doesnt my cast cover fit?? are they all the same size, can i modify the one i have?? (its the inner lip that stops it from fitting)

have advise please thaks in advance :)
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Sounds like the cover is not for the chamber, at a guess (no expert) a cast cover would rest on a cast frame, with the chamber of rendered brick or concrete construction.

I think you would be able to measure the diameter or width of the plastic chamber / rim and pick up a plastic cover of the suitable size - round or rectangle, as applicable.

This would be a proper marriage of the two materials and provide a proper seal.

Hope this helps. :)
There is no standardization of these things and pot luch what fits what.

Depending on the size of the misalignment I would be using my angle grinder to alter the lip until it fits!

But then I am very mean about these things!
hiya nipped to local builder base and picked up a 450mm standard drain cover complete with collar, all fitted better with a bit of playing with it, and a tiny bit of silicon to stop the collar from moving
i was pleased but i can still has a slight smell, (when you put your nose against it)

i cant smell it in the air any more /it fits a million times better and it looks more in keeping.

any ideas please ? am i being to be fussy? i know its not every day you start sniffing drain covers as a pass time lol :)
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Good layer of grease around the frame, then fit the cover. This usually helps seal the cover airtight if you really want to get rid of any smell!
Any foul drain will have a slight whiff to it by the nature of what it carries! Under normal circumstances a properly designed and laid drain should be ventilated via the stack(s), although some aroma will be present on lifting a cover it shouldnt be too bad. A constant strong smell may indicate there is a problem somewhere.

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