On Tue, 07 Jan 2020 21:55:04 -0000, Rod Speed wrote:

Commander Kinsey wrote
Rod Speed wrote
Commander Kinsey wrote

Why secure a loft trapdoor in a storm?

And what's the roof pitch to do with anything?

In theory you can get a suction effect similar to
what you get with an aircraft aerofoil section.

In practice it isnt seen often enough to matter.

I wonder what the roof pitch has to do with it.

That's what determines whether you get the aerofoil effect.

When the pitch is too high, you don't.

Who has a loft in a roof under 30 degrees? That wouldn't be possible.

"Close and secure loft trapdoors with bolts, particularly if roof pitch
is less than 30°"

https://www.metoffice.gov.uk/weather...afe-in-a-storm