As mentioned in an earlier blog, this is a useful phrase, with a respectable pedigree: https://en.wikipedia.org/wiki/The_wrong_type_of_snow and it can certainly be applied to the snow we had last week. After two days of fine snow and wind ie blizzards, this pile of snow was found under the roof over our Pugin bedroom, luckily just as the thaw set in.
We do not have one of those vacuum cleaners that suck up water and so presumably are also fit for snow. Anyway, if we did, it would probably suck up the fibreglass insulation as well, so we use traditional methods: hand shovel and black plastic bags. Anthony Marriott, one of our house managers and the one who detected the tell-tale drip, and I lit the roof space with a bright lamp and set about scooping up the snow and bagging it up to be disposed of for melting outside. If it melts under the roof, it can bring down a ceiling or at least make a mess of the paintwork. An hour and a half later (there were other piles elsewhere) it was all gone, and we had managed not to step between any rafters and damage the ceiling below in a more forceful way.
The photograph not only shows the offending snow, but also the cast iron roof trusses designed by the castle architect, Robert Smirke. The slates rest on cast iron purlins and are held in place by nails. It is a system that has survived the test of time, but unfortunately the seal between the slates or torching as described here: http://great-home.co.uk/repairing-torching-on-a-roof/ has long dropped off, and we have not replaced it, allowing, as an architect might say, the ingress of snow. If we had the wrong type of snow every winter, I would think about it.
4th March 2018