In message , David Cawkwell
writes
I notice my parents house has coving that must have been done in long
lengths
maybe 3 metres long as I can only see the joins on a very few places.

I have some coving to do but all I can see are 2 metre lengths in the DIY
shops

You are looking in the wrong place :-) Some of the sheds - certainly B&Q
Warehouses and Wickes sell longer lengths. Certainly any BM will stock
some of the longer lengths

You can get Gyproc coving in longer lengths - 3m, 3.6 and I think 4m.
--
Chris French, Leeds