________________________________________ >From: piclist-bounces@MIT.EDU [piclist-bounces@MIT.EDU] On Behalf Of cdb [= colin@btech-online.co.uk] >Sent: Monday, February 07, 2011 5:28 AM >To: PICLIST@MIT.EDU >Subject: [OT] Windy Gusts and buildings question. > >To the north of where I live the wind has been a bit blustery of late and >it has put me in thinking mode. > >1. I noticed that some (and I've seen this in the US as well) were taping >the outside of their windows. I posed this question at work today (and was >informed I know nothing mate), surely it would be better to tape the insid= e >of the glass instead of the outside or preferably both sides? > >My thinking is, that the wind blows from without (normally) so the strong >side of the tape which is the backing is being blown to it's weakest point= .. >When I replace cracked glass on monitors (not the lizards, they don't like >that), I only have access to the outside to begin with, when I tape the >outside, then remove the glass from the frame, if I push my finger into th= e >glass it will bend, if I push against the tape there is more resistance, >surely the same principle applies to house glass, even with the added fact >the wind pressure from a cyclone etc would be causing different pressures >within and around the building. > >2. If the windows are recessed (true, unusual here) surely it would be >better to put wood or similar across the opening as in a shutter to presen= t >a straight face to the oncoming wind thereby increasing the likelihood of >getting a more even pressure against the dwelling? > >3. Rooves get torn off partly due to unequal pressure in the building so i= n >essence they get sucked off. Wouldn't actually opening all your doors and >windows make it more likely to have less pressure differential therefore >less strain on rooves and walls and they are therefore more likely to >survive? Obviously the house contents become vulnerable. >4. If houses were round in shape instead of square angles with sharp edges= , >wouldn't a round house present less resistance to the wind thereby causing >it to dissipate or be deflected due to less surface area presented to the >wind? I think the effect on the complete building would be similar to the >.keystone in a bridge but in a horizontal fashion so the stresses would be >equal in all parts of a round building. As not everyone would be happy wit= h >a round interior, surely softening the sharp edges of a building Art Deco >style might help? > >I'm so convinced of my thoughts I am blind to where my theory falls down, >but I'm sure many amongst you will be able to point out my failings. :) > >Both my copies of the OED say I can use rooves, but you are allowed to >dispute it, and consider roofs far more refained! 1. Neil had the right answer. The reason that you put tape over the windows= is to hopefully stop large shards of glass from flying around if the window break= s. If you have double paned windows, then you need to put it on the inside of the= house too. >From what I have seen, the larger the piece of glass shard, the more likel= y it is to fly like a knife through the air. It is common to see large pieces of glass= stuck over an inch deep into 2x4s, but I can't remember ever seeing a piece smaller that about= 2 square inches stuck in anything - the smaller pieces usually just land on the floo= r a few feet away. Three pieces of tape in a star pattern works nicely. 2. Wood is definitely better at protecting the windows, not only from wind = but from flying debris (tree limbs, dirt, rocks, road signs, etc.). If you are stayi= ng within the dwelling though, it's a good idea to board and tape the windows in case a flying 2x4= blows through the plywood.=20 3. Opening the doors and windows does relieve the air pressure in the dwell= ing; however, it also allows all of the debris to go flying through the dwelling and do a= lot of damage and anything inside of dwelling can become a projectile. The houses that I've seen implode due to tornados were doomed any way and I= don't think that opening the doors and windows would have helped. I've also seen drafty= barns with plenty of air leaks have their roofs ripped off too. I've also seen tornado= s tear through=20 neighborhoods leaving some houses alone and destroying others. My personal = feeling is that if mother nature is out to get you then no amount of tape, boards, window o= pening, or whatever is going to save you. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .