Beam math
 

I'm planning on removing a load bearing wall, so I've been doing some
preliminary investigation. Don't worry I'll have an engineer when I can find
one willing to do a small job.

The wall in question is about 16' and is located on the main floor of a two
story house. The basement has a 20' steel beam (W10x30) in the same
location. I was concerned that placing the end post of the upstairs beam 4'
from the end of the basement beam would stress the steel beam too much. So I
plugged the numbers (1200 * 20 vs 1200 * 4 + 9600 + 9600) into a couple of
beam programs and discovered that the deflection numbers actually decreased.
I must be missing something here?

On Fri, 3 Sep 2004 19:51:39 -0400, "William Pounds"
wrote:

I'm planning on removing a load bearing wall, so I've been doing some
preliminary investigation. Don't worry I'll have an engineer when I can find
one willing to do a small job.

The wall in question is about 16' and is located on the main floor of a two
story house. The basement has a 20' steel beam (W10x30) in the same
location. I was concerned that placing the end post of the upstairs beam 4'
from the end of the basement beam would stress the steel beam too much. So I
plugged the numbers (1200 * 20 vs 1200 * 4 + 9600 + 9600) into a couple of
beam programs and discovered that the deflection numbers actually decreased.
I must be missing something here?

Concentrating the loads near the ends of the basement beam reduces
that beam's deflections.

Brian W

Rich_on 4-Sep-2004, Brian Whatcott wrote:

I'm planning on removing a load bearing wall, so I've been doing some
preliminary investigation. Don't worry I'll have an engineer when I can
find
one willing to do a small job.

The wall in question is about 16' and is located on the main floor of a
two
story house. The basement has a 20' steel beam (W10x30) in the same
location. I was concerned that placing the end post of the upstairs beam
4'
from the end of the basement beam would stress the steel beam too much.
So I
plugged the numbers (1200 * 20 vs 1200 * 4 + 9600 + 9600) into a couple
of
beam programs and discovered that the deflection numbers actually
decreased.
I must be missing something here?

Concentrating the loads near the ends of the basement beam reduces
that beam's deflections.

Check the shear - it might be the limiting condition. Also even if the
shear checks out, web stiffeners might be advisable.

--
rich

rich wrote:

Rich_on 4-Sep-2004, Brian Whatcott wrote:


I'm planning on removing a load bearing wall, so I've been doing some
preliminary investigation. Don't worry I'll have an engineer when I can
find
one willing to do a small job.

The wall in question is about 16' and is located on the main floor of a
two
story house. The basement has a 20' steel beam (W10x30) in the same
location. I was concerned that placing the end post of the upstairs beam
4'

from the end of the basement beam would stress the steel beam too much.

So I
plugged the numbers (1200 * 20 vs 1200 * 4 + 9600 + 9600) into a couple
of
beam programs and discovered that the deflection numbers actually
decreased.
I must be missing something here?


Concentrating the loads near the ends of the basement beam reduces
that beam's deflections.


Check the shear - it might be the limiting condition. Also even if the
shear checks out, web stiffeners might be advisable.

It is unlikley that shear or web stiffeners are required on a W10x30.

-rob

I thought you'd say some thing like if you have one bottle of Jim Beam you
get a lot of friends and some work done. Two bottles, you get more friends
and less work.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"William Pounds" wrote in message
...
I'm planning on removing a load bearing wall, so I've been doing some
preliminary investigation. Don't worry I'll have an engineer when I can find
one willing to do a small job.

The wall in question is about 16' and is located on the main floor of a two
story house. The basement has a 20' steel beam (W10x30) in the same
location. I was concerned that placing the end post of the upstairs beam 4'
from the end of the basement beam would stress the steel beam too much. So I
plugged the numbers (1200 * 20 vs 1200 * 4 + 9600 + 9600) into a couple of
beam programs and discovered that the deflection numbers actually decreased.
I must be missing something here?

"Rob Munach" wrote in message
...
rich wrote:

Rich_on 4-Sep-2004, Brian Whatcott wrote:


I'm planning on removing a load bearing wall, so I've been doing some
preliminary investigation. Don't worry I'll have an engineer when I can
find
one willing to do a small job.

The wall in question is about 16' and is located on the main floor of a
two
story house. The basement has a 20' steel beam (W10x30) in the same
location. I was concerned that placing the end post of the upstairs
beam
4'

from the end of the basement beam would stress the steel beam too much.

So I
plugged the numbers (1200 * 20 vs 1200 * 4 + 9600 + 9600) into a couple
of
beam programs and discovered that the deflection numbers actually
decreased.
I must be missing something here?


Concentrating the loads near the ends of the basement beam reduces
that beam's deflections.


Check the shear - it might be the limiting condition. Also even if the
shear checks out, web stiffeners might be advisable.

It is unlikley that shear or web stiffeners are required on a W10x30.

-rob

Thanks for the responses.

Shear seems OK. According to the #s the beam is marginal in it's original
configuration, although we've never experienced any significant bounce. My
1200 figure ((40L + 30L + 30D) *12) is probably 10% over code though.

William Pounds wrote:
"Rob Munach" wrote in message
...

rich wrote:


Rich_on 4-Sep-2004, Brian Whatcott wrote:



I'm planning on removing a load bearing wall, so I've been doing some
preliminary investigation. Don't worry I'll have an engineer when I can
find
one willing to do a small job.

The wall in question is about 16' and is located on the main floor of a
two
story house. The basement has a 20' steel beam (W10x30) in the same
location. I was concerned that placing the end post of the upstairs

beam

4'

from the end of the basement beam would stress the steel beam too much.


So I
plugged the numbers (1200 * 20 vs 1200 * 4 + 9600 + 9600) into a couple
of
beam programs and discovered that the deflection numbers actually
decreased.
I must be missing something here?


Concentrating the loads near the ends of the basement beam reduces
that beam's deflections.


Check the shear - it might be the limiting condition. Also even if the
shear checks out, web stiffeners might be advisable.


It is unlikley that shear or web stiffeners are required on a W10x30.

-rob


Thanks for the responses.

Shear seems OK. According to the #s the beam is marginal in it's original
configuration, although we've never experienced any significant bounce. My
1200 figure ((40L + 30L + 30D) *12) is probably 10% over code though.





Most residential beams rarely see much over the structure dead load. I
think I read that the average occupancy live load in a house is 6 psf.
Additionally, the more stories a beam carries, typically, the less it
bounces due to damping from walls etc.

-rob