On Sun, 31 May 2009 11:33:18 +0100, Peter wrote:

I am about to connect 4 inch waste from a new attic conversion to an
external cast iron one. Currently it rises to above roof level. Some
questions:-

As my angle grinder wont cut thro 4 inches

The way I've done it in the past is to cut through as far as possible in
two places about a foot apart, then cut down the line of the pipe to join
up the ends of the cuts, so you take out a sort of curved rectangular
section. Then you can get the angle grinder in to complete the cuts
through to the back of the pipe.

Do wear a mask: something about cutting cast iron (or maybe what's coating
the inside of the pipe!) is really nasty if you get it in your nostrils.

And do make sure the cast iron section above the cut is very adequately
supported! Really you should remove the iron pipe above the cut
(carefully! - it's extremely heavy) and continue in plastic to the top of
the stack.

Will new plastic fit inside old cast iron joints.

If you're lucky you may find a plastic push-fit joint will seal onto the
CI, but generally I'd be prepared to get one of those thick rubber sleeves
with jubilee clips to bridge metal to plastic.


--
John Stumbles -- http://yaph.co.uk

Never believe anyone who claims to be a liar