Observatory has no roof!!!

[Tony G]

All these calculations and research is worth nothing when one of these hit, and they do.
I would be worried about the whole observatory, not just the roof.

http://www.bbc.co.uk/news/uk-england-24601190

http://www.bbc.co.uk/news/uk-england-leeds-19150029

http://www.bbc.co.uk/news/uk-17987640

Just make sure that Toto is safe.

Tony G

[Mac]

How about a dome 
Mine never moved an inch, and its not bolted down either,
I was expecting to find it in someone else's garden.

Mac.

[mickw]

I think a Hip Roof would do the trick, it would have similar properties to a dome but easier (a lot) to make than a dome - but also harder to make than a gable type roof.

http://www.selfhelpandmore.com/building/roofing/designs/index.php

[MarkS]

I might still go for a monoslope (pent) roof.

Although it can generate more lift than a gable, the maximum negative pressure (i.e. lift) only occurs when the wind obliquely hits the high side first.  So if I put the high side to the North, then it will be relatively immune to the prevailing S or SW winds and the worst wind directions will be NE and NW.  For me NE and NW winds are relatively broken by the house and trees and if the roof did fly away again, it would be down the garden and not towards the house.

There is a very interesting study here which addresses monoslope and sawtooth roofs but unfortunately not gables:
http://www.davidoprevatt.com/wp-content/uploads/2010/09/bo-cui-2007-wind-effects-on-monsloped-and-sawtooth-roofs.pdf

[MarkH]

Mark, given the extremities of the weather that fateful night I wonder if  what happened was updraft. I have read a few bits and bobs on the net and from what I can make out it could have been a violent updraft which explains the extreme destruction. I recon it was just bad luck, hope all is up and running soon. Here's to some good observing weather.

[MarkS]

Could well be updraft - anything that adds more extreme gusts to an already gusty weather experience.  4 or 5 trees went down in the field next to us.