On Wednesday, December 19, 2012 8:46:29 PM UTC, JakeD wrote:
Are there any tricks I can employ to stop the condensation?

Almost anything, singly or in combination, is useful.

* Reduce the moisture indoors. Seal leaks, paint floors, fit a dehumidifier..

* Reduce the chill effect of the roof by improving its insulation. Hard work, but worth it for workshops.

* Reduce the moisture getting near the roof sheets. Just polythene sheet (or bubblewrap) stapled across the joists and with an inch or two clear of the roof is worth doing. If all else fails, it will at least tend to trap the condensation drips and route them to the edges!