In article ,
says...

On Mon, 29 Oct 2012 11:00:08 -0400, iBoaterer wrote:

Most wind damage is caused on the leeward side because if negative
pressure. Note that this is NOT taking into account airborne debris.

... but it is the wind borne debris that causes the most damage ... or
falling trees.
The reason you put up shutters is to protect from the flying ****, not
the wind. About half of the openings in my house now have impact rated
windows and we are going to do the rest when we get around to
renovating those areas. We are really only talking about 5 windows and
they have shutters.
The garage door is 150 MPH rated as is the front door and the french
doors in the bedroom. All of the openings on the south and east side
are current impact code. (9/16" laminated glass) I bet they would stop
a small caliber handgun round.

When they design for airborne debris there are parameters that are used
as far as speed, size of debris, etc. But, wind can still be a bitch in
and of itself, especially on the corners where a negative pressure is
created.

In article ,
says...

On Mon, 29 Oct 2012 13:06:16 -0400, iBoaterer wrote:

In article ,
says...

On Mon, 29 Oct 2012 11:00:08 -0400, iBoaterer wrote:

Most wind damage is caused on the leeward side because if negative
pressure. Note that this is NOT taking into account airborne debris.

... but it is the wind borne debris that causes the most damage ... or
falling trees.
The reason you put up shutters is to protect from the flying ****, not
the wind. About half of the openings in my house now have impact rated
windows and we are going to do the rest when we get around to
renovating those areas. We are really only talking about 5 windows and
they have shutters.
The garage door is 150 MPH rated as is the front door and the french
doors in the bedroom. All of the openings on the south and east side
are current impact code. (9/16" laminated glass) I bet they would stop
a small caliber handgun round.

When they design for airborne debris there are parameters that are used
as far as speed, size of debris, etc. But, wind can still be a bitch in
and of itself, especially on the corners where a negative pressure is
created.

Negative pressures have the greatest effect on the roof. That is why
we have a wind code here. Unfortunately they don't up north so I
expect to see a lot of roof damage and even total failures. Most
houses up there simply have the trusses toe nailed into the top plate,
assuming all loads are down. There is absolutely zero uplift
protection on the wall itself. You have 2 16d nails in the bottom of
the stud and whatever you get from a few nails in celotex sheathing.
Basically nothing.
Even then, most roof failures get traced back to a failure of the
building envelope and internal pressures blowing the roof off. That is
why they are so serious about protecting doors and windows.
The thing that will save them is that this is a weak cat 1 that will
be a TS by the time the eye comes ashore.
This will be a bad storm for them but don't confuse it with a
hurricane. They call the wind speeds in a cat 2 hurricane a tornado
when it hits up there and they have near total destruction in the
path.


Although I do not have the structural endorsement on my inspector's
license, I have taken a lot of the structural courses.
I could teach most of the electrical CEUs so I don't take them. I take
other disciplines, particularly structural, because it is the most
interesting.

BTW that book you linked in the note above is good but over the head
of most people and it is somewhat dated.
Florida updated our wind zones last year. That book is still talking
about the 2000 codes.

http://gfretwell.com/electrical/2012...code%20map.jpg

Corners, where the wind goes around and creates negative pressure is the
first place that your siding will rip off. If you see a mobile home that
was being towed up the interstate and the siding is coming off, it will
be in the back corners. Yes, it is outdated, I didn't bother looking for
IBC code books for a specific area or time. The rules have changed but
the physics behind it has not.

In article ,
says...

On Mon, 29 Oct 2012 13:46:38 -0400, iBoaterer wrote:

In article ,
says...

On Mon, 29 Oct 2012 13:06:16 -0400, iBoaterer wrote:

In article ,
says...

On Mon, 29 Oct 2012 11:00:08 -0400, iBoaterer wrote:

Most wind damage is caused on the leeward side because if negative
pressure. Note that this is NOT taking into account airborne debris.

... but it is the wind borne debris that causes the most damage ... or
falling trees.
The reason you put up shutters is to protect from the flying ****, not
the wind. About half of the openings in my house now have impact rated
windows and we are going to do the rest when we get around to
renovating those areas. We are really only talking about 5 windows and
they have shutters.
The garage door is 150 MPH rated as is the front door and the french
doors in the bedroom. All of the openings on the south and east side
are current impact code. (9/16" laminated glass) I bet they would stop
a small caliber handgun round.

When they design for airborne debris there are parameters that are used
as far as speed, size of debris, etc. But, wind can still be a bitch in
and of itself, especially on the corners where a negative pressure is
created.

Negative pressures have the greatest effect on the roof. That is why
we have a wind code here. Unfortunately they don't up north so I
expect to see a lot of roof damage and even total failures. Most
houses up there simply have the trusses toe nailed into the top plate,
assuming all loads are down. There is absolutely zero uplift
protection on the wall itself. You have 2 16d nails in the bottom of
the stud and whatever you get from a few nails in celotex sheathing.
Basically nothing.
Even then, most roof failures get traced back to a failure of the
building envelope and internal pressures blowing the roof off. That is
why they are so serious about protecting doors and windows.
The thing that will save them is that this is a weak cat 1 that will
be a TS by the time the eye comes ashore.
This will be a bad storm for them but don't confuse it with a
hurricane. They call the wind speeds in a cat 2 hurricane a tornado
when it hits up there and they have near total destruction in the
path.


Although I do not have the structural endorsement on my inspector's
license, I have taken a lot of the structural courses.
I could teach most of the electrical CEUs so I don't take them. I take
other disciplines, particularly structural, because it is the most
interesting.

BTW that book you linked in the note above is good but over the head
of most people and it is somewhat dated.
Florida updated our wind zones last year. That book is still talking
about the 2000 codes.

http://gfretwell.com/electrical/2012...code%20map.jpg

Corners, where the wind goes around and creates negative pressure is the
first place that your siding will rip off. If you see a mobile home that
was being towed up the interstate and the siding is coming off, it will
be in the back corners. Yes, it is outdated, I didn't bother looking for
IBC code books for a specific area or time. The rules have changed but
the physics behind it has not.

Losing your siding is not the issue, although we don't see a lot of it
here because it is so easy to lose. The real issue is losing the roof,
not just the shingles, the whole damned thing. You do get a
significant uplift but when you lose a window on the windward side, it
puts pressure in the house and adds tens of thousands of pounds of
uplift to what is on top.

Even a minimal cat 1 can put ~20,000 pounds in a 2000 sq/ft house.

It sure can. Flat roofs for industrial buildings (1/4" per foot or less
slope is considered flat) are a big problem as well, because usually
there are penthouses and such that want to turn over and once that roof
is breached, all hell breaks loose. But I digress, losing siding IS an
issue and a big one. It isn't just that the siding is gone, but when, as
you say with windows and doors, you have a positive pressure pushing the
walls out, you also have a negative pressure on the leeward side. That
is why great pains are taken anymore to make sure sheathing is nailed
correctly.