I've read a number of articles on this. One method said to use 1/2" PT
plywood 10" wide triangular shims every 24 inches to prevent water from
getting between the beams, and to let it dry out by the PT Plywood.

This seems odd to me since this would tend to weaken the beam? Does
anyone really do this? ALso I would thin kPT Plywood would be a lot
less durable than 2x10 PT? Is it really practical?


Also, let's say my header is 12' long. What carriage bolt spacing
should I use? I was thinking 24", staggered on-on-top, one-on-bottom?

Thanks!
BX1

"Buell Boy" wrote in message
ups.com...
I've read a number of articles on this. One method said to use 1/2" PT
plywood 10" wide triangular shims every 24 inches to prevent water from
getting between the beams, and to let it dry out by the PT Plywood.

This seems odd to me since this would tend to weaken the beam? Does
anyone really do this? ALso I would thin kPT Plywood would be a lot
less durable than 2x10 PT? Is it really practical?

Also, let's say my header is 12' long. What carriage bolt spacing
should I use? I was thinking 24", staggered on-on-top, one-on-bottom?


It would help to know what you're building a beam for. Unless this beam is
exposed to the elements, I would not use PT at all. Also - where was it
suggested to you to use carriage bolts on your beam? For normal
applications, simply nailing the beam up with 12's or 16's is more than
sufficient. There's overkill, and then there's overkill...

--

-Mike-

I agree that if it is not exposed to the weather (or touching the
ground since we don't know what you are spanning with this beam) I
wouldn't use pt lumber or plywood.
Real overkill would be to sandwich 1/4", 3/8" or even 1/2" steel
plate between the 2X's and bolt it all together. I only mention this
much overkill because the only time I can think of using bolts with
beams was in a past life as a framing carpenter. We framed out a grand
entry way that had curved oak staircases rising on both sides of the
entry and we built beams like this as the header(?) at the top of each
staircase tied into a manufactured exposed beam between stair headers.
Robert Smith
Jacksonville, Fl.




Mike Marlow wrote:
"Buell Boy" wrote in message
ups.com...
I've read a number of articles on this. One method said to use 1/2"
PT
plywood 10" wide triangular shims every 24 inches to prevent water
from
getting between the beams, and to let it dry out by the PT Plywood.

This seems odd to me since this would tend to weaken the beam? Does
anyone really do this? ALso I would thin kPT Plywood would be a lot
less durable than 2x10 PT? Is it really practical?

Also, let's say my header is 12' long. What carriage bolt spacing
should I use? I was thinking 24", staggered on-on-top,
one-on-bottom?


It would help to know what you're building a beam for. Unless this
beam is
exposed to the elements, I would not use PT at all. Also - where was
it
suggested to you to use carriage bolts on your beam? For normal
applications, simply nailing the beam up with 12's or 16's is more
than
sufficient. There's overkill, and then there's overkill...

--

-Mike-

So I'm slow.
I guess I should have finished reading the thread before putting
in my 2 cents worth.
You guys got to this all by yourselves. I'm not used to being
around people that think on their own.
But flitch plate? Is that a real word?
Robert Smith
Jacksonville, Fl.

Knotbob wrote:
So I'm slow.
I guess I should have finished reading the thread before putting
in my 2 cents worth.
You guys got to this all by yourselves. I'm not used to being
around people that think on their own.
But flitch plate? Is that a real word?

Yeppers, it surely is.

Flitch... 3. a beam formed of a steel plate between two beams bolted
together: in full. Flitch Beam...

In article . com,
"Buell Boy" wrote:

I've read a number of articles on this. One method said to use 1/2" PT
plywood 10" wide triangular shims every 24 inches to prevent water from
getting between the beams, and to let it dry out by the PT Plywood.

This seems odd to me since this would tend to weaken the beam? Does
anyone really do this? ALso I would thin kPT Plywood would be a lot
less durable than 2x10 PT? Is it really practical?


Also, let's say my header is 12' long. What carriage bolt spacing
should I use? I was thinking 24", staggered on-on-top, one-on-bottom?

I would talk to a -REAL- expert, not us pretend internet experts.
You are talking about engineering details that could mean the difference
between life, and well, not good things

--
--------------------------------------------------------
Personal e-mail is the n7bsn but at amsat.org
This posting address is a spam-trap and seldom read
RV and Camping FAQ can be found at
http://www.ralphandellen.us/rv

On 28 Apr 2005 05:05:51 -0700, the inscrutable "Buell Boy"
spake:

I've read a number of articles on this. One method said to use 1/2" PT
plywood 10" wide triangular shims every 24 inches to prevent water from
getting between the beams, and to let it dry out by the PT Plywood.

This seems odd to me since this would tend to weaken the beam? Does
anyone really do this? ALso I would thin kPT Plywood would be a lot
less durable than 2x10 PT? Is it really practical?


Also, let's say my header is 12' long. What carriage bolt spacing
should I use? I was thinking 24", staggered on-on-top, one-on-bottom?

I'd talk to several beam manufacturers to find one in my price range
rather than risk faulty engineering data on my or someone else's life.
Glu-lam type beams might even be cheaper than doing it yourself.

Look around for overages or cancellations from local builders, etc.

--
Don't forget the 7 P's:
Proper Prior Planning Prevents ****-Poor Performance
----------------------------------------------------
http://diversify.com Website Application Programming

This seems odd to me since this would tend to weaken the beam? Does
anyone really do this? ALso I would thin kPT Plywood would be a lot
less durable than 2x10 PT? Is it really practical?


Also, let's say my header is 12' long. What carriage bolt spacing
should I use? I was thinking 24", staggered on-on-top, one-on-bottom?


Which is it a header or a beam? A header spans the space over a door or
window. Which I suppose is a type of beam. Generally you need 1" of header
for every foot of span. Therefore a a 12' header should be constructed of
2x12 lumber, not the 2x10 you suggested.

For beams.... all bets are off. it depends on what you are supporting.

Please do not take offense, but the fact that your question is poorly formed
suggests that you are a bit in over your head. You should speak to a pro
(Engineer or experienced framer)

-Steve

"Buell Boy" wrote in message
ups.com...
I've read a number of articles on this. One method said to use 1/2" PT
plywood 10" wide triangular shims every 24 inches to prevent water from
getting between the beams, and to let it dry out by the PT Plywood.

This seems odd to me since this would tend to weaken the beam? Does
anyone really do this? ALso I would thin kPT Plywood would be a lot
less durable than 2x10 PT? Is it really practical?


Also, let's say my header is 12' long. What carriage bolt spacing
should I use? I was thinking 24", staggered on-on-top, one-on-bottom?

Thanks!
BX1

Is this supposd to be an exterior beam? If so flash the top and forget about
the shims.
If it is not exposed to weather forget about the shims.
If the 2x10s are placed side by side (oriented vertically) then it hardly
matters at all whether they are attached to each other. If they are properly
blocked to prevent rotation and buckling the there is no force that is
acting to push them apart. Nails should be fine to hold them together. I
think that the UBC has some information about required nailing. Check that
out.

-j

on 4/28/2005 11:50 AM J said the following:
"Buell Boy" wrote in message
ups.com...

I've read a number of articles on this. One method said to use 1/2" PT
plywood 10" wide triangular shims every 24 inches to prevent water from
getting between the beams, and to let it dry out by the PT Plywood.

This seems odd to me since this would tend to weaken the beam? Does
anyone really do this? ALso I would thin kPT Plywood would be a lot
less durable than 2x10 PT? Is it really practical?


Also, let's say my header is 12' long. What carriage bolt spacing
should I use? I was thinking 24", staggered on-on-top, one-on-bottom?

Thanks!
BX1


Is this supposd to be an exterior beam? If so flash the top and forget about
the shims.
If it is not exposed to weather forget about the shims.
If the 2x10s are placed side by side (oriented vertically) then it hardly
matters at all whether they are attached to each other. If they are properly
blocked to prevent rotation and buckling the there is no force that is

Correct but he's referring to a BEAM which, in most parts of the
country, is considered to be a horizontal cross member which supports a
load. He further indicates this by referring to it as a 12' HEADER.
You're speaking of a post or pilingg

I constructed a header for a 16' overhead door opening on the garage I
built. The sidewall containing the open was load-bearing for a truss
roof. I laminated a ¼" ~17'x9" steel flitch plate between the 2x10's
and bolted the whole thing together with carriage bolts as he proposes
(staggered). The garage is now 20 years old and there is absolutely NO
sag in that header - none. It'll take a fire to make that puppy sag.
Overbuilt? I dunno. That's what the plans called for in the header.

IIRC correctly the ¼" steel flitch plate w/bolts may have been an
alternative to either ½" or 3/4" ply nailed.

BX1's best bet is to check with Building/Zoning or Community Development
in his town and see what they say. To overbuild is never a crimeg

"Unquestionably Confused" wrote in message
news:BH9ce.944 Is this
snip
I constructed a header for a 16' overhead door opening on the garage I
built. The sidewall containing the open was load-bearing for a truss
roof. I laminated a ¼" ~17'x9" steel flitch plate between the 2x10's
and bolted the whole thing together with carriage bolts as he proposes
(staggered). The garage is now 20 years old and there is absolutely NO
sag in that header - none. It'll take a fire to make that puppy sag.
Overbuilt? I dunno. That's what the plans called for in the header.

IIRC correctly the ¼" steel flitch plate w/bolts may have been an
alternative to either ½" or 3/4" ply nailed.

BX1's best bet is to check with Building/Zoning or Community Development
in his town and see what they say. To overbuild is never a crimeg

I'm working on a garage design. For a span greater than 9 feet, our local
code requires two 2x12s sandwiched around a 1/8" steel flitch plate. I'm
curious where one would obtain a 17-18' long steel plate 11.25" wide.

todd

I'm working on a garage design. For a span greater than 9 feet, our local
code requires two 2x12s sandwiched around a 1/8" steel flitch plate. I'm
curious where one would obtain a 17-18' long steel plate 11.25" wide.

todd

From a steel fabricator?

You sure they wouldn't accept a glue-lam or LVL beam?

-J

on 4/28/2005 2:45 PM J said the following:
I'm working on a garage design. For a span greater than 9 feet, our local
code requires two 2x12s sandwiched around a 1/8" steel flitch plate. I'm
curious where one would obtain a 17-18' long steel plate 11.25" wide.

todd


From a steel fabricator?

Exactly, and it's my bad on my earlier post, it IS a 2x12 with the
flitch plate and it's still not going anywhere.

Ordered up the flitch plate from local steel dealer that supplies the
I-beams, etc. and gave them the dimensions. Brought it in, dropped it
off the flatbed. Had a small table top drill press and set up a little
staging area about six or eight inches off the ground and drilled the
holes to spec.

I must have been crazy to do it but I hoisted all three components up
into position by myself using a fence comealong, chains and temporary
supports. I was quite proud of having done it by myself. SWMBO thought
I was crazy. Now, I would tend to agreeg

That's old tech...glue lams have long ago replaced
that method. Look up I-joists, glue-lams, or LVL.

The old 2 2x12 method will work, but there are
much better methods for headers.

http://www.i-joist.org/home.asp

http://www.ufpi.com/product/lvl/

http://www.curtislumber.ca/products/gluelams.htm




Todd Fatheree wrote:

I'm working on a garage design. For a span greater than 9 feet, our local
code requires two 2x12s sandwiched around a 1/8" steel flitch plate. I'm
curious where one would obtain a 17-18' long steel plate 11.25" wide.

Todd Fatheree wrote:

I'm working on a garage design. For a span greater than 9 feet, our
local
code requires two 2x12s sandwiched around a 1/8" steel flitch plate. I'm
curious where one would obtain a 17-18' long steel plate 11.25" wide.

With today's engineered beams, the above sounds like very old technology
to me.

Think I'd do a little more research.

Lew

Is this supposd to be an exterior beam? If so flash the top and forget
about
the shims.
If it is not exposed to weather forget about the shims.
If the 2x10s are placed side by side (oriented vertically) then it
hardly
matters at all whether they are attached to each other. If they are
properly
blocked to prevent rotation and buckling the there is no force that is

Correct but he's referring to a BEAM which, in most parts of the
country, is considered to be a horizontal cross member which supports a
load.

I am too. By vertically I mean that the beam is 9 1/4" deep with the 2x side
by side instead of stacked (which would be a bad idea).

He further indicates this by referring to it as a 12' HEADER.
You're speaking of a post or pilingg

Actually I DID write about a beam. With a post, bonding the two (or more)
together is MORE necessary to prevent buckling.

I constructed a header for a 16' overhead door opening on the garage I
built. The sidewall containing the open was load-bearing for a truss
roof. I laminated a ¼" ~17'x9" steel flitch plate between the 2x10's
and bolted the whole thing together with carriage bolts as he proposes
(staggered). The garage is now 20 years old and there is absolutely NO
sag in that header - none. It'll take a fire to make that puppy sag.
Overbuilt? I dunno. That's what the plans called for in the header.

A 17' load bearing span is definitely too much for a couple of 2x10's. In
your application, the steel is doing most of the work and the wood is there
to keep it from buckling (also to nail to I presume). I'd hardly consider
that to be overbuilt.

IIRC correctly the ¼" steel flitch plate w/bolts may have been an
alternative to either ½" or 3/4" ply nailed.

Without knowing the loads, it is hard to say, but it is quite unlikely that
you could have substituted a 9" wide piece of 1/2" plywood for the steel.
Making the beam deeper (perhaps using the plywood as a web) would certainly
help. Beam deflection decreases with the cube of the beam depth.

BX1's best bet is to check with Building/Zoning or Community Development
in his town and see what they say.

Good advice. This is really a simple case and they should be able to give
him an answer based on codes.

To overbuild is never a crimeg

Actually I consider it equivalent to theft if I am the one paying for it. If
not, then it is simply good practice.

-j

On 28-Apr-2005, Unquestionably Confused wrote:

To overbuild is never a crime

Overbuilt can cause a failure. For example, if something is designed and
built correctly, it will tend to show excessive deflections before failure,
providing a warning. Overbuilt things can fail spectacularly without
any warning. That could be a crime or at least expose you to a civil
lawsuit.

Mike

"Michael Daly" wrote in message
...
On 28-Apr-2005, Unquestionably Confused wrote:

To overbuild is never a crime

Overbuilt can cause a failure. For example, if something is designed and
built correctly, it will tend to show excessive deflections before
failure,
providing a warning. Overbuilt things can fail spectacularly without
any warning. That could be a crime or at least expose you to a civil
lawsuit.

Mike

Um, I'm not so sure about this. In fact I'm trying to remember if I've ever
seen that happen. Do you have any specific cases?

I'd venture that things fail more often by being underbuilt, OR not being
built to plan. Such failures are commonplace.

Overbuilding is not particularly dangerous, but it is wasteful.

-j

In article , "Michael Daly" wrote:
On 28-Apr-2005, Unquestionably Confused wrote:

To overbuild is never a crime

Overbuilt can cause a failure. For example, if something is designed and
built correctly, it will tend to show excessive deflections before failure,
providing a warning. Overbuilt things can fail spectacularly without
any warning. That could be a crime or at least expose you to a civil
lawsuit.

Uhhh .... howzat again? Seems to me that if it fails, then by definition it
was underbuilt, not over....

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

Michael Daly wrote:

On 28-Apr-2005, Unquestionably Confused wrote:

To overbuild is never a crime

Overbuilt can cause a failure. For example, if something is designed and
built correctly, it will tend to show excessive deflections before
failure,
providing a warning. Overbuilt things can fail spectacularly without
any warning.

Where you run into the kind of problem you describe is when a strong but
brittle material is substituted for a weaker but more ductile material.
The ductile material will bend before it breaks, the brittle material will
simply break.

As for something "designed and built correctly" showing "excessive
deflections before failure", certainly one can design things that way but
that doesn't mean that it's the only correct way. Concrete for example
doesn't flex noticeably before it breaks so by your reasoning concrete
should never be used as a building material.

When dealing with wooden beams, making the beam stronger than called for is
not going to result in sudden failure with no warning unless the original
design would also fail suddenly with no warning at a lighter load.

That could be a crime or at least expose you to a civil
lawsuit.

I would like you to quote the statute which makes it a criminal offense to
build something stronger than is required. Or provide reference to a civil
case where someone was successfully sued for building something stronger
than was specified.

Mike

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

In article ,
J. Clarke wrote:
Michael Daly wrote:

On 28-Apr-2005, Unquestionably Confused wrote:

To overbuild is never a crime

Overbuilt can cause a failure. For example, if something is designed and
built correctly, it will tend to show excessive deflections before
failure,
providing a warning. Overbuilt things can fail spectacularly without
any warning.

Where you run into the kind of problem you describe is when a strong but
brittle material is substituted for a weaker but more ductile material.

*NOT* necessarily true.

The ductile material will bend before it breaks, the brittle material will
simply break.

As for something "designed and built correctly" showing "excessive
deflections before failure", certainly one can design things that way but
that doesn't mean that it's the only correct way. Concrete for example
doesn't flex noticeably before it breaks so by your reasoning concrete
should never be used as a building material.

When dealing with wooden beams, making the beam stronger than called for is
not going to result in sudden failure with no warning unless the original
design would also fail suddenly with no warning at a lighter load.

*NOT* necessarily true.

Engineering for systems under stress, particularly dynamic stresses, is a
_complex_ and _complicated_ subject.

*ALL* the components have to be considered, =both= singly, and in combination.
'Over-building' _one_ component can result in excessive transfer of stress
to _other_ components, Leading to failure of _that_ component under conditions
that are _less_ severe -- as measured for the overall system -- than the
original design was spec'ed to handle.

There are numerous real-world instances of this *exact* thing happening.
One of the easiest places to find them is in the world of home-built, plans-
built, aircraft. Firstly, in general, the 'safety margin' on _any_ aircraft
design is extremely small. "1.6" is typical for commercial construction.
Homebuilts usually are designed with higher margins, because there is more
variability in the quality of construction. However, there are =many= cases
on record, including after-the-fact engineering analyses, where a home-builder
has modified a design -- to =strengthen= some part of it -- where said mods
have led to _premature_failure_ of other areas of the design. Higher "point
stresses" occurred in the modified design, as a result of the modification,
than the original design was designed to handle.

On 29-Apr-2005, "J. Clarke" wrote:

Concrete for example
doesn't flex noticeably before it breaks so by your reasoning concrete
should never be used as a building material.

Concrete is a perfect example of the problem and one where overdesign is
a problem. Too much steel reinforcement in a small beam compared to less
steel in a deeper beam - the lightly reinforced beam will fail slowly with
the ductile steel failing in tension. The overbuilt beam with too much
steel will fail suddenly and in a brittle manner by failure of the concrete
in compression.

When dealing with wooden beams, making the beam stronger than called for is
not going to result in sudden failure with no warning unless the original
design would also fail suddenly with no warning at a lighter load.

The lighter beam would bend considerably before failure. The heavy beam
can carry a significant overload and can cause it's supports to fail without
warning. You can't look at a building by considering its components individually.
You have to look at the entire structure as a system.

I would like you to quote the statute which makes it a criminal offense to
build something stronger than is required.

If an engineer or architect is responsible for the design of a building,
they are required to ensure that it does not fail in a manner that does not
give warning (i.e it must fail in a ductile manner). If the design of one
component results in an unexpected failure, whether from over- or underdesign,
this results in professional liability. Maybe not the Code of Hammurabi, but
there are still legal consequences - such as criminal negligence causing death.

Mike

I've tried OVER and OVER to reach the local building departments. Their
website is not useful, and reaching a person by phone is a 2-3 week
proposition. Since the Hurricanes here (I'm in Florida in an area
where 3 hit last year), there is so much building going on that it's
almost impossible to speak to anyone in the building or code
departments. Permits in our town are 6-12 months from the time of
application.

Good suggestion though I just WISH I had a building inspector avaiable.
I also talked to a clerk about the project. She said they are so backed
up that projects like mine are not being permitted at this time- she
basically said "have at it"..

Welcome to Florida!






IRC correctly the =BC" steel flitch plate w/bolts may have been an
alternative to either =BD" or 3/4" ply nailed.

BX1's best bet is to check with Building/Zoning or Community
Development
in his town and see what they say. To overbuild is never a crimeg

On 28 Apr 2005 05:05:51 -0700, "Buell Boy" wrote:

I've read a number of articles on this. One method said to use 1/2" PT
plywood 10" wide triangular shims every 24 inches to prevent water from
getting between the beams, and to let it dry out by the PT Plywood.

This seems odd to me since this would tend to weaken the beam? Does
anyone really do this? ALso I would thin kPT Plywood would be a lot
less durable than 2x10 PT? Is it really practical?


Also, let's say my header is 12' long. What carriage bolt spacing
should I use? I was thinking 24", staggered on-on-top, one-on-bottom?


Take a step back and make sure you're using the right material for the
application. I don't know what you're up to, but when someone says
"beam" I think "steel". Like I said, I have no idea what you're
doing, just make sure you're doing it the right way- saving a couple
of bucks does you no good if you're dead.



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