GardenBanter.co.uk - View Single Post

Les Hemmings · 13-01-2007, 05:32 AM posted to uk.rec.gardening

wrote:
Greenhouses do sometimes get Damaged from Strong winds & Gales , Today
we have had very Strong winds , it looks like the Weather is getting a
lot worse , today we have had very Strong Gales & I would suggest
anybody who has a Greenhouse that they secure all there Vents & make
sure all Doors are closed , make sure to remove any objects around the
Greenhouse that can blow on to your Greenhouse , it looks like the
Weather is getting a Lot worse , Today is the 11/01/2007 & the winds
have been very Strong & look to get a lot Stronger in the Uk

Sealing a structure in very high winds has the opposite effect. As the
pressure drops outside (moving air, lower pressure) the high pressure inside
the structure causes it to explode. It's the major cause of building loss in
hurricanes, all those people you see in those pre-hurricane news reports
boarding up their homes to make them airtight are also the ones whos houses
star in those spectacular "expoding house" shots during the storm.

The winds recently were strong enough to cause me to open both ends of our
polytunnels a tad to equalise the pressure. If you don't believe me, watch
the water in your toilet bowl during very high winds. Strong gusts cause the
water to be pushed down the bowl as the pressure inside stays constant and
the exterior pressure decreases.

Your advice seems consistant with your job. More damaged greenhouses equals
more money for yourself. If everyone were to button up their brand spanky
new greenhouse all nice and tight you'd be quids in! So perhaps you knew all
about the pressure effects after all? Or is that just my cynical, black
heart?

I'd agree with the loose objects outside the 'house advice. But i would open
vents just a bit to enable the relatively higher pressure air to escape
during strong gusts and equalise things inside and out.

I removed the words "low and scheming spammer" out of politness.....

Les

--
Remove Frontal Lobes to reply direct.

"Oh Bother!" said the Borg, "We've assimilated Pooh!"

"That's 10 times I've explained binary to you. I won't tell you a 3rd
time!"

http://armsofmorpheus.blogspot.com/

http://www.richarddawkins.net/index.php

Les Hemmings a.a #2251 SA