I've had a little bit of a leak in the shop and have been putting black goop on the outside to try and seal it which hasn't done a lot of good as the seal breaks with the movement of the timber so letting in the wet stuff. Pete's been round this morning and together we've worked out how to sort it out and make it water tight, which basically involves trapping a skirt of DPM underneath the marine ply joining strips on the outside such that it will bridge the installed DPM and so prevent the ingress of water...that's the plan, hopefully.
You can see that we cut away a little bit of the internal wall and it's very clear that the water is coming in by capillary action between the base and the panel wall. Next job will be to get a rather large tarp over this end of the workshop so that I can get a good circulation of air but still keep off the driving rain. Can't put up the tarp at the moment tho' as it's blowing about Force 6 here at the moment so it'll have to wait for another day.