On Wed, 15 Aug 2007 08:12:23 -0700, Mr Uncalled-For wrote:

On Aug 15, 9:23 am, Mr Uncalled-For wrote:
I have a 3 1/2 inch drainpipe that I need to T into

Well, I checked with a plumber and apparently I would:
* Not be permitted by 'building control' to use the strap-on-boss
solution.
* Would have to do it all in cast iron (externally, that is).

You could cut into the pipe and fit a cast iron branch. There are
various manufactures, but you can find a .pdf catalogue of the one I know
most about at www.saint-gobain.co.uk - you'ld be looking for a Timesaver
Soil catalogue where you'll find details of GT12 90x100mm stepped
couplings designed for 3.5" LCC pipe and GT06 100mm branches. If the
stepped couplings were frowned upon by the council then you'ld have to
get a 3.5" LCC branch, they are still available.

You did say that space is tight but maybe you can get a disc cutter to do
most of the work. Do you have control over the whole stack or is someone
above you. If the former, then you have the luxury of time for the
installation at least.

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