cast downpipe

has anybody got any advices on freeing cast joints, need to change a 4 foot length of cast down pipe of which has been blocked for over 3 years, and whats the going prices for cast pipe
any help would be appreciated

Any particular reason you want to stick with cast iron? Are you in a conservation area or something?

If cast iron is your only option then freeing a joint can be somewhat tricky and may require liberal amounts of heat. As to prices... not got the foggiest but I suspect it won't be all that cheap.

In my experience, cast iron rain goods can come apart fairly easily once the wall fixings have been cut or removed; it's usually a case of pulling the joints apart, or waggling them from side to side until they come loose. On the other hand if there is a lot of rusting and scale inside the joint, it may be nearly impossible to get them apart without damage, and it's not worth trying.

If you want iron downpipe or fittings to go with your existing guttering, try searching through reclamation yards. Be prepared to pay quite surprising prices.