On Sat, 22 Sep 2018 13:53:23 -0700 (PDT), Mathew Newton wrote:

If there are places that retain water I think the strip and
replace
is the better option and I suspect your builder would agree.

It is difficult to define 'retain' as even with a proper fall some parts
of the roof will remain wet for a period after rain and it can be
difficult to tell the difference between wet and pooling.

That's why I suggested watching how it dries. Where it's drained well
will dry much quicker than a place that hasn't. You'd need to examine
the "wet" places as the roof dries. Where there are hollows there
will be hills. The hills will drain better than the hollows so will
dry first. That doesn't mean the hollows retain water they could
drain as well and dry closely after the hills. Hollows that "retain"
water will take longer to dry and examination of them would reveal
how much lying water is there.

As you have highlighted, there are complications with any of the
proposed fixes but I think I'll be opting for the strip and rebuild.

As you say that (should!) put you into the place you had hoped to be
now, the Insurance backed guarantee is just pragmatic. From the
builders point of view he actually gets a reputation boost. I'm sure
you'll be saying he cocked up but when approached admited it and
straight away offered to make good at his cost and you both came up
with several solutions for you to choose.

--
Cheers
Dave.