On Tuesday, January 30, 2018 at 9:48:41 PM UTC, newshound wrote:
On 30/01/2018 20:12, Brian Gaff wrote:
Or the old trick of using a smaller pipe inside the cut off old one of
course.
Brian


OP doesn't really give enough detail, but yes that could be the simplest
way.

Copper pipe comes in 28, 35, 42 mm OD with solder fittings available.
With enough overlap, silicone rubber should give an adequate seal. You
can also wrap the inner pipe with PVC electrical tape so as to make it a
tight push fit.

Thanks,
I took your advice and extended inside the house to push it out from the wall, it was more accessible than expected.