Why secure a loft trapdoor in a storm? And what's the roof pitch to do with anything?

"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

On 07/01/2020 20:01, Commander Kinsey wrote:
Why secure a loft trapdoor in a storm?* And what's the roof pitch to do
with anything?

"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


Bernouilli.

I don't know their reasons, but mine used to come open during high winds
dumping tons of old muck and dust onto my landing. Its now held shut with
duct tape. No nasty whining noises or rattles either. The roof on this
property is open ie it can bee seen there are gaps under the tiles, so one
assumes if that hole was through to the house and a really spectacular wind
came it could blow many tiles off the roof.
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Commander Kinsey" wrote in message
newsp.0d1gkmz9wdg98l@glass...
Why secure a loft trapdoor in a storm? And what's the roof pitch to do with
anything?

"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

On Tue, 07 Jan 2020 20:01:24 -0000, Birdbrain Macaw (aka "Commander Kinsey",
"James Wilkinson", "Steven ******","Bruce Farquar", "Fred Johnson, etc.),
the pathological resident idiot and attention whore of all the uk ngs,
blathered again:

FLUSH the abnormal sociopathic attention whore's latest attention-baiting
sick bull**** unread again

--
about Birdbrain Macaw's (now "James Wilkinson" LOL)
trolling:
"He is a well known attention seeking troll and every reply you
make feeds him.
Starts many threads most of which die quick as on the UK groups anyone
with sense Kill filed him ages ago which is why he now cross posts to
the US groups for a new audience.
This thread was unusual in that it derived and continued without him
to a large extent and his silly questioning is an attempt to get
noticed again."
MID:

--
ItsJoanNotJoann addressing Birdbrain Macaw's (now "James Wilkinson" LOL):
"You're an annoying troll and I'm done with you and your
stupidity."
MID:

--
AndyW addressing Birdbrain:
"Troll or idiot?...
You have been presented with a viewpoint with information, reasoning,
historical cases, citations and references to back it up and wilfully
ignore all going back to your idea which has no supporting information."
MID:

--
Phil Lee adressing Birdbrain Macaw:
"You are too stupid to be wasting oxygen."
MID:

--
Phil Lee describing Birdbrain Macaw:
"I've never seen such misplaced pride in being a ****ing moronic motorist."
MID:

--
Tony944 addressing Birdbrain Macaw:
"I seen and heard many people but you are on top of list being first class
ass hole jerk. ...You fit under unconditional Idiot and should be put in
mental institution.
MID:

--
Pelican to Birdbrain Macaw:
"Ok. I'm persuaded . You are an idiot."
MID:

--
DerbyDad03 addressing Birdbrain Macaw (now "James Wilkinson" LOL):
"Frigging Idiot. Get the hell out of my thread."
MID:

--
Kerr Mudd-John about Birdbrain Macaw (now "James Wilkinson" LOL):
"It's like arguing with a demented frog."
MID:

--
Mr Pounder Esquire about Birdbrain Macaw (now "James Wilkinson" LOL):
"the **** poor delivery boy with no hot running water, 11 cats and
several parrots living in his hovel."
MID:

--
Rob Morley about Birdbrain:
"He's a perennial idiot"
MID: 20170519215057.56a1f1d4@Mars

--
JoeyDee to Birdbrain
"I apologize for thinking you were a jerk. You're just someone with an IQ
lower than your age, and I accept that as a reason for your comments."
MID: l-september.org

--
Sam Plusnet about Birdbrain (now "James Wilkinson Sword" LOL):
"He's just desperate to be noticed. Any attention will do, no matter how
negative it may be."
MID:

--
asking Birdbrain:
"What, were you dropped on your head as a child?"
MID:

--
Christie addressing endlessly driveling Birdbrain Macaw (now "James
Wilkinson" LOL):
"What are you resurrecting that old post of mine for? It's from last
month some time. You're like a dog who's just dug up an old bone they
hid in the garden until they were ready to have another go at it."
MID:

--
Mr Pounder's fitting description of Birdbrain Macaw:
"You are a well known fool, a tosser, a pillock, a stupid unemployable
sponging failure who will always live alone and will die alone. You will not
be missed."
MID:

--
Richard to pathetic ****** Hucker:
"You haven't bred?
Only useful thing you've done in your pathetic existence."
MID:

--
about Birdbrain (now "James Wilkinson" LOL):
""not the sharpest knife in the drawer"'s parents sure made a serious
mistake having him born alive -- A total waste of oxygen, food, space,
and bandwidth."
MID:

--
Mr Pounder exposing sociopathic Birdbrain:
"You will always be a lonely sociopath living in a ******** with no hot
running water with loads of stinking cats and a few parrots."
MID:

--
francis about Birdbrain (now "James Wilkinson" LOL):
"He seems to have a reputation as someone of limited intelligence"
MID:

--
Peter Moylan about Birdbrain (now "James Wilkinson" LOL):
"If people like JWS didn't exist, we would have to find some other way to
explain the concept of "invincible ignorance"."
MID:

--
Lewis about nym-shifting Birdbrain:
"Typical narcissist troll, thinks his **** is so grand he has the right to
try to force it on everyone."
MID:

"Commander Kinsey" wrote in message
newsp.0d1gkmz9wdg98l@glass...

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.

"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

On Tue, 7 Jan 2020 20:13:13 -0000, Brainless & Daft (Sofa), the notorious,
troll-feeding senile idiot, blathered again:

I don't know their reasons,

Righto, but you'll feed the sociopathic attention whore anyway, right,
Brainless & Daft?

On Wed, 8 Jan 2020 07:35:23 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:


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.

In practice BOTH of you are clinically insane trolling idiots!

--
Marland answering senile Rodent's statement, "I don't leak":
"That¢s because so much **** and ****e emanates from your gob that there is
nothing left to exit normally, your arsehole has clammed shut through disuse
and the end of prick is only clear because you are such a ******."
Message-ID:

On Tue, 07 Jan 2020 20:35:23 -0000, Rod Speed wrote:



"Commander Kinsey" wrote in message
newsp.0d1gkmz9wdg98l@glass...

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.

"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

Ah, you mean one of those strange ones that opens downwards? Mine lifts up, a much more sensible arrangement. It simply cannot open itself, it's too heavy.

On Tue, 07 Jan 2020 20:13:13 -0000, Brian Gaff (Sofa) wrote:

I don't know their reasons, but mine used to come open during high winds
dumping tons of old muck and dust onto my landing. Its now held shut with
duct tape. No nasty whining noises or rattles either. The roof on this
property is open ie it can bee seen there are gaps under the tiles, so one
assumes if that hole was through to the house and a really spectacular wind
came it could blow many tiles off the roof.
Brian

On Tue, 07 Jan 2020 20:35:23 -0000, Rod Speed wrote:



"Commander Kinsey" wrote in message
newsp.0d1gkmz9wdg98l@glass...

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.

The conservatory I've half built is staying firmly put. I guess I bolted it together well :-)

"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

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.

"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

"Commander Kinsey" wrote in message
newsp.0d1jwqxqwdg98l@glass...
On Tue, 07 Jan 2020 20:35:23 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1gkmz9wdg98l@glass...

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.

The conservatory I've half built is staying firmly put. I guess I bolted
it together well :-)

You can get flatish roofs lifted right off by strong
winds. basically due to the aerofoil effects.

"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

On Wed, 8 Jan 2020 08:55:04 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH the two clinically insane sociopaths' endless troll****

--
Another typical retarded conversation between our two village idiots,
Birdbrain and Rodent Speed:

Birdbrain: "You beat me to it. Plain sex is boring."

Senile Rodent: "Then **** the cats. That wont be boring."

Birdbrain: "Sell me a de-clawing tool first."

Senile Rodent: "Wont help with the teeth."

Birdbrain: "They've never gone for me with their mouths."

Rodent Speed: "They will if you are stupid enough to try ****ing them."

Birdbrain: "No, they always use claws."

Rodent Speed: "They wont if you try ****ing them. Try it and see."

Message-ID:

On Wed, 8 Jan 2020 08:57:36 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH the two sociopathic prize idiots' endless troll****

--
Another typical retarded "conversation" between the two resident idiots:

Birdbrain: "But imagine how cool it was to own slaves."

Senile Rodent: "Yeah, right. Feed them, clothe them, and fix them when
they're broken.
After all, you paid good money for them. Then you've got to keep an eye
on them all the time."

Birdbrain: "Better than having to give them wages on top of that."

Senile Rodent: "Specially when they make more slaves for you
and produce their own food and clothes."

MID:

On Tue, 07 Jan 2020 21:57:36 -0000, Rod Speed wrote:



"Commander Kinsey" wrote in message
newsp.0d1jwqxqwdg98l@glass...
On Tue, 07 Jan 2020 20:35:23 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1gkmz9wdg98l@glass...

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.

The conservatory I've half built is staying firmly put. I guess I bolted
it together well :-)

You can get flatish roofs lifted right off by strong
winds. basically due to the aerofoil effects.

Not done the roof yet. Hmmm, perhaps I should secure it very tightly. Mind you polycarbonate can snap easily in a wind. How powerful is aerofoil in a wind? The limit would be 14psi, which would be horrendous, but I assume that needs a lot of wind.

"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

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.

But how can that get to the loft hatch?

"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

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

"Commander Kinsey" wrote in message
newsp.0d1n2gjawdg98l@glass...
On Tue, 07 Jan 2020 21:57:36 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1jwqxqwdg98l@glass...
On Tue, 07 Jan 2020 20:35:23 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1gkmz9wdg98l@glass...

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.

The conservatory I've half built is staying firmly put. I guess I
bolted
it together well :-)

You can get flatish roofs lifted right off by strong
winds. basically due to the aerofoil effects.

Not done the roof yet. Hmmm, perhaps I should secure it very tightly.
Mind you polycarbonate can snap easily in a wind.

How powerful is aerofoil in a wind?

Flat roofs regularly get ripped right off and land on the
neighbour's etc. Corse that's in cyclones and hurricanes.

The limit would be 14psi, which would be horrendous, but I assume that
needs a lot of wind.

Yeah, normally only in cyclones and hurricanes etc.

"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

"Commander Kinsey" wrote in message
newsp.0d1n3vgmwdg98l@glass...
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.

But how can that get to the loft hatch?

The suction effect in the roof space sees air moved
out of the house into the roof space, lifting the hatch.

"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

"Commander Kinsey" wrote in message
newsp.0d1n42n5wdg98l@glass...
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?

You do so a few mansard roofs like that.

That wouldn't be possible.

Corse it is with a mansard roof.

"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

On Wed, 8 Jan 2020 10:19:33 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH the two clinically insane asshole's troll****

--
Another typical retarded "conversation" between Birdbrain and senile Rodent:

Senile Rodent: " Did you ever dig a hole to bury your own ****?"

Birdbrain: "I do if there's no flush toilet around."

Senile Rodent: "Yeah, I prefer camping like that, off by myself with
no dunnys around and have always buried the ****."

MID:

On Wed, 8 Jan 2020 10:22:28 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH the two sociopathic prize idiots' endless troll**** unread

--
Another typical retarded "conversation" between the Scottish ****** and the
senile Ozzietard:

Birdbrain: "Horse **** doesn't stink."

Senile Rodent: "It does if you roll in it."

Birdbrain: "I've never worked out why, I assumed it was maybe meateaters
that made stinky ****, but then why does vegetarian human **** stink? Is it
just the fact that we're capable of digesting meat?"

Senile Rodent: "Nope, some cow **** stinks too."

Message-ID:

On Wed, 8 Jan 2020 10:18:22 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH the two prize idiots' endless troll****

--
Another TYPICAL retarded "conversation" between sociopath Rodent and
sociopath Birdbrain from August 26th 2018:

Birdbrain: "I have one head but 5 fingers."

Senile Rodent: "Obvious lie. You hairy legged cross dressers are so inbred
that you all have two heads."

Birdbrain: "You're the one that likes hairy legs remember?"

Senile Rodent: "The problem isnt the hairy legs, it's the gross inbreeding
that
produces two headed unemployables like you."

Birdbrain: "So why did you mention hairy legs?"

Senile Rodent: "Because that's what those who arent actually stupid enough
to shave their legs have."

Birdbrain: "You only have hairy legs if both of the following are true:
1) You're quite far back on the evolutionary scale.
2) You haven't learned what a razor is for."

Senile Rodent: "Only a terminal ****wit or a woman shaves their legs."

Birdbrain: "There is literally zero point in having hair all over your
body."

Senile Rodent: "There is even less point in wasting your time changing what
you are born with."

MID:

On Tue, 07 Jan 2020 23:18:22 -0000, Rod Speed wrote:



"Commander Kinsey" wrote in message
newsp.0d1n2gjawdg98l@glass...
On Tue, 07 Jan 2020 21:57:36 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1jwqxqwdg98l@glass...
On Tue, 07 Jan 2020 20:35:23 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1gkmz9wdg98l@glass...

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.

The conservatory I've half built is staying firmly put. I guess I
bolted
it together well :-)

You can get flatish roofs lifted right off by strong
winds. basically due to the aerofoil effects.

Not done the roof yet. Hmmm, perhaps I should secure it very tightly..
Mind you polycarbonate can snap easily in a wind.

How powerful is aerofoil in a wind?

Flat roofs regularly get ripped right off and land on the
neighbour's etc. Corse that's in cyclones and hurricanes.

I wanted a more quantitative answer.

The limit would be 14psi, which would be horrendous, but I assume that
needs a lot of wind.

Yeah, normally only in cyclones and hurricanes etc.

We don't get those.

"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

On Tue, 07 Jan 2020 23:19:33 -0000, Rod Speed wrote:



"Commander Kinsey" wrote in message
newsp.0d1n3vgmwdg98l@glass...
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.

But how can that get to the loft hatch?

The suction effect in the roof space sees air moved
out of the house into the roof space, lifting the hatch.

how could that happen? Surely aerofoil works on the roof itself, lifting the tiles off.

And my hatch is made of wood, way too heavy to lift like that. And hardly the end of the world if it opened, it might give me a fright that's all.

"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

On Tue, 07 Jan 2020 23:22:28 -0000, Rod Speed wrote:



"Commander Kinsey" wrote in message
newsp.0d1n42n5wdg98l@glass...
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?

You do so a few mansard roofs like that.

That wouldn't be possible.

Corse it is with a mansard roof.

That doesn't make sense. Look at the picture in https://en.wikipedia.org/wiki/Mansard_roof
There are rooms in the roof.

"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

"Commander Kinsey" wrote in message
newsp.0d1qkkgdwdg98l@glass...
On Tue, 07 Jan 2020 23:18:22 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1n2gjawdg98l@glass...
On Tue, 07 Jan 2020 21:57:36 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1jwqxqwdg98l@glass...
On Tue, 07 Jan 2020 20:35:23 -0000, Rod Speed

wrote:



"Commander Kinsey" wrote in message
newsp.0d1gkmz9wdg98l@glass...

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.

The conservatory I've half built is staying firmly put. I guess I
bolted
it together well :-)

You can get flatish roofs lifted right off by strong
winds. basically due to the aerofoil effects.

Not done the roof yet. Hmmm, perhaps I should secure it very tightly.
Mind you polycarbonate can snap easily in a wind.

How powerful is aerofoil in a wind?

Flat roofs regularly get ripped right off and land on the
neighbour's etc. Corse that's in cyclones and hurricanes.

I wanted a more quantitative answer.

There isnt one. What it takes to lift the roof off depends
on too many other variables, particularly how well the
roof structure is attached to the top of the walls and
the detail of how the roof decking is attached to the
purlins. And the profile of the roof too. Mine has a
curvature across the roof in one direction achieved
by purlins of different depth. The aerodynamic effect
obviously depends on the wind direction. And mine
has quite deep barge boards about 18" high which
affect the wind over the roof too.

The limit would be 14psi, which would be horrendous, but I assume that
needs a lot of wind.

Yeah, normally only in cyclones and hurricanes etc.

We don't get those.

Yes you do, only the name changes.

"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

"Commander Kinsey" wrote in message
newsp.0d1qmig1wdg98l@glass...
On Tue, 07 Jan 2020 23:19:33 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1n3vgmwdg98l@glass...
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.

But how can that get to the loft hatch?

The suction effect in the roof space sees air moved
out of the house into the roof space, lifting the hatch.

how could that happen? Surely aerofoil works on the roof itself, lifting
the tiles off.

The tiles arent an airtight surface like an aircraft
wing so you do get considerable movement of
air out of the roofspace before the tiles come off.

And my hatch is made of wood, way too heavy to lift like that.

You're wrong when the roof is of lower slope.

And hardly the end of the world if it opened, it might give me a fright
that's all.

Sure, but that's just as true of the other stuff like
shutters that it suggests should be shut and secured.

"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

"Commander Kinsey" wrote in message
newsp.0d1qorjjwdg98l@glass...
On Tue, 07 Jan 2020 23:22:28 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1n42n5wdg98l@glass...
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?

You do so a few mansard roofs like that.

That wouldn't be possible.

Corse it is with a mansard roof.

That doesn't make sense.

Corse it does.

Look at the picture in https://en.wikipedia.org/wiki/Mansard_roof
There are rooms in the roof.

They arent all done like that.

"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

On Wed, 08 Jan 2020 00:49:59 -0000, Rod Speed wrote:



"Commander Kinsey" wrote in message
newsp.0d1qkkgdwdg98l@glass...
On Tue, 07 Jan 2020 23:18:22 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1n2gjawdg98l@glass...
On Tue, 07 Jan 2020 21:57:36 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1jwqxqwdg98l@glass...
On Tue, 07 Jan 2020 20:35:23 -0000, Rod Speed

wrote:



"Commander Kinsey" wrote in message
newsp.0d1gkmz9wdg98l@glass...

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.

The conservatory I've half built is staying firmly put. I guess I
bolted
it together well :-)

You can get flatish roofs lifted right off by strong
winds. basically due to the aerofoil effects.

Not done the roof yet. Hmmm, perhaps I should secure it very tightly.
Mind you polycarbonate can snap easily in a wind.

How powerful is aerofoil in a wind?

Flat roofs regularly get ripped right off and land on the
neighbour's etc. Corse that's in cyclones and hurricanes.

I wanted a more quantitative answer.

There isnt one. What it takes to lift the roof off depends
on too many other variables, particularly how well the
roof structure is attached to the top of the walls and
the detail of how the roof decking is attached to the
purlins. And the profile of the roof too. Mine has a
curvature across the roof in one direction achieved
by purlins of different depth. The aerodynamic effect
obviously depends on the wind direction. And mine
has quite deep barge boards about 18" high which
affect the wind over the roof too.

Somebody must have measured what wind speed is required to develop a vacuum of a certain PSI.

The limit would be 14psi, which would be horrendous, but I assume that
needs a lot of wind.

Yeah, normally only in cyclones and hurricanes etc.

We don't get those.

Yes you do, only the name changes.

Because of the lack of severity.

On Wed, 08 Jan 2020 00:57:35 -0000, Rod Speed wrote:



"Commander Kinsey" wrote in message
newsp.0d1qorjjwdg98l@glass...
On Tue, 07 Jan 2020 23:22:28 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1n42n5wdg98l@glass...
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?

You do so a few mansard roofs like that.

That wouldn't be possible.

Corse it is with a mansard roof.

That doesn't make sense.

Corse it does.

Look at the picture in https://en.wikipedia.org/wiki/Mansard_roof
There are rooms in the roof.

They arent all done like that.

Your turn to provide a picture.

"Commander Kinsey" wrote in message
newsp.0d1uwfcmwdg98l@glass...
On Wed, 08 Jan 2020 00:49:59 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1qkkgdwdg98l@glass...
On Tue, 07 Jan 2020 23:18:22 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1n2gjawdg98l@glass...
On Tue, 07 Jan 2020 21:57:36 -0000, Rod Speed

wrote:



"Commander Kinsey" wrote in message
newsp.0d1jwqxqwdg98l@glass...
On Tue, 07 Jan 2020 20:35:23 -0000, Rod Speed

wrote:



"Commander Kinsey" wrote in message
newsp.0d1gkmz9wdg98l@glass...

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.

The conservatory I've half built is staying firmly put. I guess I
bolted
it together well :-)

You can get flatish roofs lifted right off by strong
winds. basically due to the aerofoil effects.

Not done the roof yet. Hmmm, perhaps I should secure it very tightly.
Mind you polycarbonate can snap easily in a wind.

How powerful is aerofoil in a wind?

Flat roofs regularly get ripped right off and land on the
neighbour's etc. Corse that's in cyclones and hurricanes.

I wanted a more quantitative answer.

There isnt one. What it takes to lift the roof off depends
on too many other variables, particularly how well the
roof structure is attached to the top of the walls and
the detail of how the roof decking is attached to the
purlins. And the profile of the roof too. Mine has a
curvature across the roof in one direction achieved
by purlins of different depth. The aerodynamic effect
obviously depends on the wind direction. And mine
has quite deep barge boards about 18" high which
affect the wind over the roof too.

Somebody must have measured what wind speed is required to develop a
vacuum of a certain PSI.

Not even possible with all those other variables.

And I have a line of massive trees along the S side of
the house where the strongest winds come from too.

The limit would be 14psi, which would be horrendous, but I assume that
needs a lot of wind.

Yeah, normally only in cyclones and hurricanes etc.

We don't get those.

Yes you do, only the name changes.

Because of the lack of severity.

Wrong, as always. You lot get winds that bring down
lots of trees and **** lots of roofs and houses.

"Commander Kinsey" wrote in message
newsp.0d1uw2hawdg98l@glass...
On Wed, 08 Jan 2020 00:57:35 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1qorjjwdg98l@glass...
On Tue, 07 Jan 2020 23:22:28 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1n42n5wdg98l@glass...
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?

You do so a few mansard roofs like that.

That wouldn't be possible.

Corse it is with a mansard roof.

That doesn't make sense.

Corse it does.

Look at the picture in https://en.wikipedia.org/wiki/Mansard_roof
There are rooms in the roof.

They arent all done like that.

Your turn to provide a picture.

Don't need to. Plenty of places with mansard roofs have
storage with access hatches in the roof space even
tho that isnt as useful as with a normal pitched roof.

On Wed, 8 Jan 2020 11:53:52 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH the two sociopathic brain dead trolls latest absolutely idiotic
troll**** unread


--
Typical retarded "conversation" between the Scottish ****** and the senile
Ozzietard:

Birdbrain: "Horse **** doesn't stink."

Senile Rodent: "It does if you roll in it."

Birdbrain: "I've never worked out why, I assumed it was maybe meateaters
that made stinky ****, but then why does vegetarian human **** stink? Is it
just the fact that we're capable of digesting meat?"

Senile Rodent: "Nope, some cow **** stinks too."

Message-ID:

On Wed, 8 Jan 2020 11:57:35 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH another load of the two trolling sociopaths' endless troll****

--
TYPICAL retarded "conversation" between sociopath Rodent and sociopath
Birdbrain from August 26th 2018:

Birdbrain: "I have one head but 5 fingers."

Senile Rodent: "Obvious lie. You hairy legged cross dressers are so inbred
that you all have two heads."

Birdbrain: "You're the one that likes hairy legs remember?"

Senile Rodent: "The problem isnt the hairy legs, it's the gross inbreeding
that
produces two headed unemployables like you."

Birdbrain: "So why did you mention hairy legs?"

Senile Rodent: "Because that's what those who arent actually stupid enough
to shave their legs have."

Birdbrain: "You only have hairy legs if both of the following are true:
1) You're quite far back on the evolutionary scale.
2) You haven't learned what a razor is for."

Senile Rodent: "Only a terminal ****wit or a woman shaves their legs."

Birdbrain: "There is literally zero point in having hair all over your
body."

Senile Rodent: "There is even less point in wasting your time changing what
you are born with."

MID:

On Wed, 8 Jan 2020 14:56:53 +1100, Rcantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH another load of the usual idiotic troll**** unread

--
Another typical retarded conversation between our two village idiots,
Birdbrain and Rodent Speed:

Birdbrain: "You beat me to it. Plain sex is boring."

Senile Rodent: "Then **** the cats. That wont be boring."

Birdbrain: "Sell me a de-clawing tool first."

Senile Rodent: "Wont help with the teeth."

Birdbrain: "They've never gone for me with their mouths."

Rodent Speed: "They will if you are stupid enough to try ****ing them."

Birdbrain: "No, they always use claws."

Rodent Speed: "They wont if you try ****ing them. Try it and see."

Message-ID:

On Wed, 8 Jan 2020 11:49:59 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH troll****

--
Another typical retarded "conversation" between the two resident idiots:

Birdbrain: "But imagine how cool it was to own slaves."

Senile Rodent: "Yeah, right. Feed them, clothe them, and fix them when
they're broken.
After all, you paid good money for them. Then you've got to keep an eye
on them all the time."

Birdbrain: "Better than having to give them wages on top of that."

Senile Rodent: "Specially when they make more slaves for you
and produce their own food and clothes."

MID:

On Wed, 8 Jan 2020 14:54:29 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH another 94 lines of absolutely idiotic troll**** unread again

--
Another typical retarded "conversation" between Birdbrain and senile Rodent:

Senile Rodent: " Did you ever dig a hole to bury your own ****?"

Birdbrain: "I do if there's no flush toilet around."

Senile Rodent: "Yeah, I prefer camping like that, off by myself with
no dunnys around and have always buried the ****."

MID:

On 08/01/2020 00:53, Rod Speed wrote:


"Commander Kinsey" wrote in message
newsp.0d1qmig1wdg98l@glass...
On Tue, 07 Jan 2020 23:19:33 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1n3vgmwdg98l@glass...
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.

But how can that get to the loft hatch?

The suction effect in the roof space sees air moved
out of the house into the roof space, lifting the hatch.

how could that happen?* Surely aerofoil works on the roof itself,
lifting the tiles off.

The tiles arent an airtight surface like an aircraft
wing so you do get considerable movement of
air out of the roofspace before the tiles come off.

And my hatch is made of wood, way too heavy to lift like that.

You're wrong when the roof is of lower slope.

And hardly the end of the world if it opened, it might give me a
fright that's all.

Sure, but that's just as true of the other stuff like
shutters that it suggests should be shut and secured.

What of the possibility of air being able to rush from the house into
the reduced pressure of the loft, so suddenly changing the differential
pressure between the inside and outside of the roof and making it more
likely that the roof is damaged or ripped off?

SteveW

"Steve Walker" wrote in message
...
On 08/01/2020 00:53, Rod Speed wrote:


"Commander Kinsey" wrote in message
newsp.0d1qmig1wdg98l@glass...
On Tue, 07 Jan 2020 23:19:33 -0000, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.0d1n3vgmwdg98l@glass...
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.

But how can that get to the loft hatch?

The suction effect in the roof space sees air moved
out of the house into the roof space, lifting the hatch.

how could that happen? Surely aerofoil works on the roof itself,
lifting the tiles off.

The tiles arent an airtight surface like an aircraft
wing so you do get considerable movement of
air out of the roofspace before the tiles come off.

And my hatch is made of wood, way too heavy to lift like that.

You're wrong when the roof is of lower slope.

And hardly the end of the world if it opened, it might give me a fright
that's all.

Sure, but that's just as true of the other stuff like
shutters that it suggests should be shut and secured.

What of the possibility of air being able to rush from the house into the
reduced pressure of the loft, so suddenly changing the differential
pressure between the inside and outside of the roof and making it more
likely that the roof is damaged or ripped off?

It doesn't work like that, essentially because the hatch lifted by the
reduced pressure in the roof space doesn't see enough air moving
thru the narrow gap around the edges of the hatch to matter.