Water butt diverter from old cast iron downpipe

[crt]

I've got an old cast iron down pipe (5"?) which takes the rainwater down to the drain from the roof guttering.

I want to connect a diverter for a water butt.

What is the best way to do this given that the off the shelf diverters are narrower, metric sizes?

Do I:

1. cut the pipe; and

2. insert a length of new 68mm down pipe with the diverter attached using appropriate reducing imperial:metric fittings?

If so, are the reducing fittings easy to obtain?

Or, is there an easier method? (e.g. a larger imperial diverter).

All suggestions gratefully received.

Thanks.

 

[Watchmaker]

Our local B & Q sell a rubber, double diameter connector, made for this purpose. It clamps to the cast iron pipe, and the smaller diameter plastic pipe, with Jubilee type clips. In my opinion, it's not the best looking device around but, it might solve your problem