Jonathan: This evening we can hear, outside, the build-up to Abigail – the first storm that the Met Office has named. Thankfully – well, for us in Uist, the strongest winds will be further north, in Harris and Lewis. In South Uist and Eriskay we’re expecting gusts to reach about 70mph. Buildings that are neglected, and objects left lying around, are where the damage will be worst. Here at An Garradh Mor, we find that – because of the layout of the garden walls and the house, a severe gale will be strongest when from the west, yet least likely to cause us damage: it’s often less powerful winds from the SW or NW that do more damage, and a wind from the NE – coming down from the heights of Eisebhal and across it’s southern corries, resulting in turbulence that make it unpredictable and violent. (Thankfully storms from that direction are extremely rare: in fact, I can’t recall one in all the time we’ve been here). For the same reason, Carrick is very vulnerable to a SE gale: Mother Nature seems to have designed Beinn Sgiathan to stir up the wind into a frenzy of extremely violent twisters that you can hear whistling across the ground towards you! At Eight Askernish, it’s winds from the SW that seem to do the most damage, due to their frequency and sheer brute force. In short, whatever the weather, we have to prepare for the worst – don’t chance it!
Every autumn we re-fit to the extraskeleton of each greenhouse boards that keep the worst of the wind-pressure (and flying debris!) off the glass and the aluminium of the greenhouse itself.
Although built only of softwood, the extraskeleton is much much stronger than the greenhouse, and more resilient: the whole thing is designed to disipate wind energy and take any physical impacts. At worst, even if the glass broke, the aluminium frame should remain intact and in shape. Though we have occasionally suffered damage to the cladding boards – on one occasion cut through like butter by a flying piece (maybe 1.5m x 0.5m) of metal roof sheeting – neither the greenhouses themselves – nor even the basic extraskeletons – have never been damaged in a storm. The timber frame of the extraskeleton and boarding together give about 50% coverage (horizontally – there’s no boarding across the top), but measurements show that this reduces light only by about 20% at most.