Thanks to all for the information regarding pregolas.

Following much of the advice given here, ours was successfully built over
the Easter weekend ;-))

My tip for others, buy a special spirit-level for posts. It clips onto
the post and gives the levels of both sides at the same time. Cost about £6
and well worth it IMO.
Then the gravel supports the posts really easily..... my husband was very
impressed with the URG info.

Marina
E. Sx