Guest
On Thursday, April 3, 2014 3:38:00 AM UTC-4, Cydrome Leader wrote:
Any idiot who leans a ladder against drywall deserves to fall through it.
Any idiot who leans a ladder against drywall deserves to fall through it.
Guest
On Thursday, April 3, 2014 7:59:04 AM UTC-4, Phil Hobbs wrote:
Apparently you're unaware of the defective fastener hardware on the market. The fastener of choice for a blind connection would be a lag bolt. The withdrawal strength is huge:
p= 8,100 x G^3/2 x D^3/4 x L in the inch-pound system, where:
p= pounds withdrawal force
D= bolt shank diameter
G= specific gravity of structural wood at 12% moisture content
L= length of bolt thread penetration into the wood
This of course assumes a properly installed bolt using drilled pilot hole and tightening torque. The joist will give way before the bolt lets go in most cases, and if you use multiple bolts, the whole house will come down before they let go.
Apparently you're unaware of the defective fastener hardware on the market. The fastener of choice for a blind connection would be a lag bolt. The withdrawal strength is huge:
p= 8,100 x G^3/2 x D^3/4 x L in the inch-pound system, where:
p= pounds withdrawal force
D= bolt shank diameter
G= specific gravity of structural wood at 12% moisture content
L= length of bolt thread penetration into the wood
This of course assumes a properly installed bolt using drilled pilot hole and tightening torque. The joist will give way before the bolt lets go in most cases, and if you use multiple bolts, the whole house will come down before they let go.
R
Robert Baer
Guest
Jim Thompson wrote:
R
Robert Baer
Guest
Jim Thompson wrote:
capacitive type; Zircon "StudSensor 2 (TM)".
Pat 4,099,118 "A portable sensor adapted to be moved along a wall to
indicate a change in the dielectric constant of the wall thereby to
signal the presence of a wall stud within the wall."
Have seen 2-3 brands counting this one.
OK; the "better" of the 2 types i have seen is basically the
capacitive type; Zircon "StudSensor 2 (TM)".
Pat 4,099,118 "A portable sensor adapted to be moved along a wall to
indicate a change in the dielectric constant of the wall thereby to
signal the presence of a wall stud within the wall."
Have seen 2-3 brands counting this one.
Guest
On Thursday, April 3, 2014 9:16:32 AM UTC-4, Phil Hobbs wrote:
That's like asking for an attribution of F= m x a .
Good luck finding that 6" u-bolt you will need to wrap around that 2 x 4 stud. If you get on the top side maybe a threaded rod would work better for you. In any case, you're going to end up with a mess, use fasteners way more expensive than needed and spend half the day doing a 10-minute job.
That's like asking for an attribution of F= m x a .
You put up your monkey bars your way, and I'll do it mine. And if I
can't spot a cracked U-bolt, it's my own lookout. Cracked posters, I
can spot without even seeing them.
Good luck finding that 6" u-bolt you will need to wrap around that 2 x 4 stud. If you get on the top side maybe a threaded rod would work better for you. In any case, you're going to end up with a mess, use fasteners way more expensive than needed and spend half the day doing a 10-minute job.
M
micky
Guest
On Wed, 02 Apr 2014 07:49:51 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
If Jim posted to sed, why did someone change things to ahr?
I have a zircon from 25 or 30 years ago and it works just fine. It
lights up when I get to one edge of the stud and unlights 1.5 inches
later when I pass the other edge.
I wouldn't assume blueprints are right.
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
If Jim posted to sed, why did someone change things to ahr?
I have a zircon from 25 or 30 years ago and it works just fine. It
lights up when I get to one edge of the stud and unlights 1.5 inches
later when I pass the other edge.
I wouldn't assume blueprints are right.
P
Phil Hobbs
Guest
On 4/2/2014 10:10 PM, krw@attt.bizz wrote:
Except that since you're doing it blind, you don't notice if there's a
knot in the rafter right there. U-bolts for me.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Except that since you're doing it blind, you don't notice if there's a
knot in the rafter right there. U-bolts for me.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
J
John Devereux
Guest
bloggs.fredbloggs.fred@gmail.com writes:
Just so I can follow this (US-oriented?) Man Talk....
The "studs" are strips of wood behind plaster board, is that right? Not
the nails holding it on. So we are talking about locating the wood, not
just the nails?
--
John Devereux
Just so I can follow this (US-oriented?) Man Talk....
The "studs" are strips of wood behind plaster board, is that right? Not
the nails holding it on. So we are talking about locating the wood, not
just the nails?
--
John Devereux
S
Syd Rumpo
Guest
On 02/04/2014 06:17, RobertMacy wrote:
<snip>
I have one of those, I think it must be called a 'NEWS' as it has those
letters printed around the circumference.
Cheers
--
Syd
<snip>
I have one of those, I think it must be called a 'NEWS' as it has those
letters printed around the circumference.
Cheers
--
Syd
Guest
On Thursday, April 3, 2014 11:43:43 AM UTC-4, Phil Hobbs wrote:
You do understand I'm talking about this gizmo:
http://www.solarpanelstore.com/pdf/lag%20pullout.pdf
This table is reproduced all over the place.
On 04/03/2014 09:29 AM, bloggs.fredbloggs.fred@gmail.com wrote:
On Thursday, April 3, 2014 9:16:32 AM UTC-4, Phil Hobbs wrote:
On 4/3/2014 9:07 AM, bloggs.fredbloggs.fred@gmail.com wrote:
On Thursday, April 3, 2014 7:59:04 AM UTC-4, Phil Hobbs wrote:
On 4/2/2014 10:10 PM, krw@attt.bizz wrote:
On Wed, 02 Apr 2014 20:13:05 -0400, Phil Hobbs
hobbs@electrooptical.net> wrote:
On 4/2/2014 3:16 PM, bulegoge@columbus.rr.com wrote:
If I were hanging HEAVY stuff, I would use the stud
finder
first then I would use some brads and punch them in and
make
sure I really got the center of the stud
If I were hanging heavy stuff, I sure wouldn't rely on a
screw
into a
rafter.
Depends on the numbers. A few hundred pounds is no problem.
*A*
screw, well probably not. ;-)
Except that since you're doing it blind, you don't notice if
there's a
knot in the rafter right there. U-bolts for me.
Apparently you're unaware of the defective fastener hardware on
the
market. The fastener of choice for a blind connection would be a
lag
bolt. The withdrawal strength is huge:
p= 8,100 x G^3/2 x D^3/4 x L in the inch-pound system, where:
p= pounds withdrawal force
D= bolt shank diameter
G= specific gravity of structural wood at 12% moisture content
L= length of bolt thread penetration into the wood
This of course assumes a properly installed bolt using drilled
pilot
hole and tightening torque. The joist will give way before the
bolt
lets go in most cases, and if you use multiple bolts, the whole
house
will come down before they let go.
It's amazing how much smarter Wikipedia makes people when they
don't
give attribution.
That's like asking for an attribution of F= m x a .
You put up your monkey bars your way, and I'll do it mine. And if
I
can't spot a cracked U-bolt, it's my own lookout. Cracked
posters, I
can spot without even seeing them.
Good luck finding that 6" u-bolt you will need to wrap around that 2
x 4 stud. If you get on the top side maybe a threaded rod would work
better for you. In any case, you're going to end up with a mess, use
fasteners way more expensive than needed and spend half the day
doing a 10-minute job.
I can buy bolts like that at my local hardware store, about two blocks
from my lab.
Don't they have hardware stores where you are?
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
You do understand I'm talking about this gizmo:
http://www.solarpanelstore.com/pdf/lag%20pullout.pdf
This table is reproduced all over the place.
P
Phil Hobbs
Guest
On 4/3/2014 9:07 AM, bloggs.fredbloggs.fred@gmail.com wrote:
It's amazing how much smarter Wikipedia makes people when they don't
give attribution.
You put up your monkey bars your way, and I'll do it mine. And if I
can't spot a cracked U-bolt, it's my own lookout. Cracked posters, I
can spot without even seeing them.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
It's amazing how much smarter Wikipedia makes people when they don't
give attribution.
You put up your monkey bars your way, and I'll do it mine. And if I
can't spot a cracked U-bolt, it's my own lookout. Cracked posters, I
can spot without even seeing them.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
R
RobertMacy
Guest
On Wed, 02 Apr 2014 18:28:10 -0700, RosemontCrest
<rosemontcrest.deletethis@yahoo.com> wrote:
And there's always that 'rhythm' pattern broken up some where, just where
you plan on placing the nail.
<rosemontcrest.deletethis@yahoo.com> wrote:
And there's always that 'rhythm' pattern broken up some where, just where
you plan on placing the nail.
Guest
On Thursday, April 3, 2014 2:13:24 PM UTC-4, Jeff Liebermann wrote:
That author is a jackass moron too, a complete retarded idiot with absolutely no sense of cause and effect. The primary reason for going 24"OC is to reduce thermal shorts by 30%, that would be two studs in 4 ft versus 3 (duh).. There's more I could tell you about it, but you and some others around here are getting so smug, I won't.
Are you serious??? The main ingredient of production efficiency is uniformity. The vast majority of new houses are in developments where all the houses are the exact same plan give or take a right<->left flip.
That author is a jackass moron too, a complete retarded idiot with absolutely no sense of cause and effect. The primary reason for going 24"OC is to reduce thermal shorts by 30%, that would be two studs in 4 ft versus 3 (duh).. There's more I could tell you about it, but you and some others around here are getting so smug, I won't.
Are you serious??? The main ingredient of production efficiency is uniformity. The vast majority of new houses are in developments where all the houses are the exact same plan give or take a right<->left flip.
P
Phil Hobbs
Guest
On 04/03/2014 09:29 AM, bloggs.fredbloggs.fred@gmail.com wrote:
I can buy bolts like that at my local hardware store, about two blocks
from my lab.
Don't they have hardware stores where you are?
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
On Thursday, April 3, 2014 9:16:32 AM UTC-4, Phil Hobbs wrote:
On 4/3/2014 9:07 AM, bloggs.fredbloggs.fred@gmail.com wrote:
On Thursday, April 3, 2014 7:59:04 AM UTC-4, Phil Hobbs wrote:
On 4/2/2014 10:10 PM, krw@attt.bizz wrote:
On Wed, 02 Apr 2014 20:13:05 -0400, Phil Hobbs
hobbs@electrooptical.net> wrote:
On 4/2/2014 3:16 PM, bulegoge@columbus.rr.com wrote:
If I were hanging HEAVY stuff, I would use the stud
finder
first then I would use some brads and punch them in and
make
sure I really got the center of the stud
If I were hanging heavy stuff, I sure wouldn't rely on a
screw
into a
rafter.
Depends on the numbers. A few hundred pounds is no problem.
*A*
screw, well probably not. ;-)
Except that since you're doing it blind, you don't notice if
there's a
knot in the rafter right there. U-bolts for me.
Apparently you're unaware of the defective fastener hardware on
the
market. The fastener of choice for a blind connection would be a
lag
bolt. The withdrawal strength is huge:
p= 8,100 x G^3/2 x D^3/4 x L in the inch-pound system, where:
p= pounds withdrawal force
D= bolt shank diameter
G= specific gravity of structural wood at 12% moisture content
L= length of bolt thread penetration into the wood
This of course assumes a properly installed bolt using drilled
pilot
hole and tightening torque. The joist will give way before the
bolt
lets go in most cases, and if you use multiple bolts, the whole
house
will come down before they let go.
It's amazing how much smarter Wikipedia makes people when they
don't
give attribution.
That's like asking for an attribution of F= m x a .
You put up your monkey bars your way, and I'll do it mine. And if
I
can't spot a cracked U-bolt, it's my own lookout. Cracked
posters, I
can spot without even seeing them.
Good luck finding that 6" u-bolt you will need to wrap around that 2
x 4 stud. If you get on the top side maybe a threaded rod would work
better for you. In any case, you're going to end up with a mess, use
fasteners way more expensive than needed and spend half the day
doing a 10-minute job.
I can buy bolts like that at my local hardware store, about two blocks
from my lab.
Don't they have hardware stores where you are?
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
J
Jeff Liebermann
Guest
On Thu, 3 Apr 2014 04:54:40 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:
I guess there are more than one jackass online. I don't have time
right now to work out the numbers, but I will ask one of the achitects
in the adjacent office for an explanation. Meanwhile:
<http://www.builderonline.com/construction/studs-at-24-inch-spacing.aspx>
Correct. Too bad that many houses are not built with such dimensional
considerations in mine, but prefer to locate doors and windows based
what is outside. I have a forest outside and am on a hillside. My
windows are positioned for the best view, my foundation avoides old
tree stumps, and my doors mostly by the hillside topgraphy. If they
don't quite fit 16" stud spacing, I could care less.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
bloggs.fredbloggs.fred@gmail.com wrote:
I guess there are more than one jackass online. I don't have time
right now to work out the numbers, but I will ask one of the achitects
in the adjacent office for an explanation. Meanwhile:
<http://www.builderonline.com/construction/studs-at-24-inch-spacing.aspx>
Correct. Too bad that many houses are not built with such dimensional
considerations in mine, but prefer to locate doors and windows based
what is outside. I have a forest outside and am on a hillside. My
windows are positioned for the best view, my foundation avoides old
tree stumps, and my doors mostly by the hillside topgraphy. If they
don't quite fit 16" stud spacing, I could care less.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
J
Jeff Liebermann
Guest
On Thu, 03 Apr 2014 13:01:29 +0100, John Devereux
<john@devereux.me.uk> wrote:
>Just so I can follow this (US-oriented?) Man Talk....
Sorry. It's a side effect of being a part time real estate
speculator.
They're the approximately 2x4" or 2x6" vertical braces that hold up
the walls and ceiling. They are usually made from wood, but can also
be made from bent steel sheet metal. The structure inside the walls
is called platform framing (NOT balloon framing).
<http://802.11junk.com/jeffl/crud/framing.jpg>
<http://en.wikipedia.org/wiki/Framing_(construction)>
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
<john@devereux.me.uk> wrote:
>Just so I can follow this (US-oriented?) Man Talk....
Sorry. It's a side effect of being a part time real estate
speculator.
They're the approximately 2x4" or 2x6" vertical braces that hold up
the walls and ceiling. They are usually made from wood, but can also
be made from bent steel sheet metal. The structure inside the walls
is called platform framing (NOT balloon framing).
<http://802.11junk.com/jeffl/crud/framing.jpg>
<http://en.wikipedia.org/wiki/Framing_(construction)>
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Guest
On Thursday, April 3, 2014 5:38:54 PM UTC-4, Jeff Liebermann wrote:
Thompson's language was that he wanted locate the "joists in the wall." Now I ask you, who has joists in their wall? Is he hanging thi stuff on the cieling or the wall? Who would know.
That's all well known and not very interesting. The word he is looking for is staggered stud wall. The attempt at exhausting the full spectrum of framing practice is rather weak, apparently those people never heard of trussed walls for one.
That brings up the issue of "blocking" which refers to additional stud material installed in the wall vertically or horizontally at various places to accommodate interior accessories like towel racks, cabinets, trim and other things.
Having the house on stepped foundation doesn't have much to do with the framing.
Thompson's language was that he wanted locate the "joists in the wall." Now I ask you, who has joists in their wall? Is he hanging thi stuff on the cieling or the wall? Who would know.
That's all well known and not very interesting. The word he is looking for is staggered stud wall. The attempt at exhausting the full spectrum of framing practice is rather weak, apparently those people never heard of trussed walls for one.
That brings up the issue of "blocking" which refers to additional stud material installed in the wall vertically or horizontally at various places to accommodate interior accessories like towel racks, cabinets, trim and other things.
Having the house on stepped foundation doesn't have much to do with the framing.
Guest
On Thursday, April 3, 2014 5:59:35 PM UTC-4, Jeff Liebermann wrote:
<snip>
5/8 is code everywhere for it fire stop value, not strength.
<snip>
5/8 is code everywhere for it fire stop value, not strength.
J
Jeff Liebermann
Guest
On Thu, 3 Apr 2014 11:25:25 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:
Perhaps it would be helpful if you would refer to the original
problem, which was your suggestion that Jim simply measure 16" from
some unspecified starting point, in order to locate the studs upon
which he can hang his heavy power tools. My only comment was to
suggest that not all houses are built on 16" centers and that it might
be better to use a stud finder instead of a tape measure.
Please don't.
Incidentally, there are other ways to do framing on both 16" and 24"
centers.
<https://www.pcc.edu/about/events/sustainability-training/documents/advanced-wall-framing.pdf>
Oddity: Despite the studs usually being on 16" centers, bathroom
towel racks are most commonly available in 24" lengths. I find myself
buying the 24" variety and cutting them down to 16", or adding a
horizontal firebreak just for the towel rack.
I'm always serious, except when I'm joking. You should be able to
recognize the difference without assistance, but since you apparently
need help, I will disclose that at least this time, I am serious.
>The main ingredient of production efficiency is uniformity.
My house, and possibly Jim Thompson's, are custom homes. That means
they were not cut out of a cookie cutter floor plan, and in my case,
did not have the alleged benefits of having the ground deforested,
bulldozed, flattened, leveled, and paved into something that would
make it convenient to use 16" centers.
Very true. I do some real estate speculation and avoid such houses.
They are usually badly built, where the developer has cut costs in
every conceivable manner. Oddly, I did see one local housing
development that used steel studs on 24" centers. I may have taken
some photos during the framing. I'll dig.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
bloggs.fredbloggs.fred@gmail.com wrote:
Perhaps it would be helpful if you would refer to the original
problem, which was your suggestion that Jim simply measure 16" from
some unspecified starting point, in order to locate the studs upon
which he can hang his heavy power tools. My only comment was to
suggest that not all houses are built on 16" centers and that it might
be better to use a stud finder instead of a tape measure.
Please don't.
Incidentally, there are other ways to do framing on both 16" and 24"
centers.
<https://www.pcc.edu/about/events/sustainability-training/documents/advanced-wall-framing.pdf>
Oddity: Despite the studs usually being on 16" centers, bathroom
towel racks are most commonly available in 24" lengths. I find myself
buying the 24" variety and cutting them down to 16", or adding a
horizontal firebreak just for the towel rack.
I'm always serious, except when I'm joking. You should be able to
recognize the difference without assistance, but since you apparently
need help, I will disclose that at least this time, I am serious.
>The main ingredient of production efficiency is uniformity.
My house, and possibly Jim Thompson's, are custom homes. That means
they were not cut out of a cookie cutter floor plan, and in my case,
did not have the alleged benefits of having the ground deforested,
bulldozed, flattened, leveled, and paved into something that would
make it convenient to use 16" centers.
Very true. I do some real estate speculation and avoid such houses.
They are usually badly built, where the developer has cut costs in
every conceivable manner. Oddly, I did see one local housing
development that used steel studs on 24" centers. I may have taken
some photos during the framing. I'll dig.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
J
Jeff Liebermann
Guest
On Thu, 3 Apr 2014 07:38:00 +0000 (UTC), Cydrome Leader
<presence@MUNGEpanix.com> wrote:
All the drywall in this area has been 5/8" since about 1970. There is
some 1/2" drywall in older buildings. The local lumber yards don't
even stock 1/2" drywall any more. I've never even seen 1/4" drywall.
5/8" on 24" centers is to local code.
With 1/4" drywall, just leaning on the wall will probably cause it to
crack. Ok, let's do the math:
<http://www.gypsum.org/wp/wp-content/uploads/2011/11/GA-235-10.pdf>
Worst case is where the ladder ends up in the middle of the 24" span,
and where one rail of the ladder delivers the full load. I'll assume
a 30 degree angle between the ladder and the wall. For a 180 lb
person, near the top of a 6ft ladder, that's a maximum of 90 lbs of
force on the wall, 1ft from the edge or 90 ft-lbs. Looking at the
above tables, I find:
thickness Min flex perpendicular
inches strength ft-lbs
1/4" 50
1/2" 100-110
5/8" 140-150
Therefore, the ladder will probably destroy the 1/4" drywall. The
load is safe for 1/2" but too close for comfort. At 5/8" an
approximately 30% safety factor for worst case is good enough. Note
that real drywall ladders have a flat plate attached to the top of the
rails to distribute the load instead of concentrate it.
Incidentally, I have only a little drywall in my house. The rest is a
mix of t&g strips and plywood wood paneling.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
<presence@MUNGEpanix.com> wrote:
All the drywall in this area has been 5/8" since about 1970. There is
some 1/2" drywall in older buildings. The local lumber yards don't
even stock 1/2" drywall any more. I've never even seen 1/4" drywall.
5/8" on 24" centers is to local code.
With 1/4" drywall, just leaning on the wall will probably cause it to
crack. Ok, let's do the math:
<http://www.gypsum.org/wp/wp-content/uploads/2011/11/GA-235-10.pdf>
Worst case is where the ladder ends up in the middle of the 24" span,
and where one rail of the ladder delivers the full load. I'll assume
a 30 degree angle between the ladder and the wall. For a 180 lb
person, near the top of a 6ft ladder, that's a maximum of 90 lbs of
force on the wall, 1ft from the edge or 90 ft-lbs. Looking at the
above tables, I find:
thickness Min flex perpendicular
inches strength ft-lbs
1/4" 50
1/2" 100-110
5/8" 140-150
Therefore, the ladder will probably destroy the 1/4" drywall. The
load is safe for 1/2" but too close for comfort. At 5/8" an
approximately 30% safety factor for worst case is good enough. Note
that real drywall ladders have a flat plate attached to the top of the
rails to distribute the load instead of concentrate it.
Incidentally, I have only a little drywall in my house. The rest is a
mix of t&g strips and plywood wood paneling.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558