On 18 Mar 2005 08:36:10 -0800, wrote:

That's why I figured I might as well overdo it.

I've now decided to go with a Steel I-beam (looks like it will be the
same or cheaper than lumber - but will make a much smaller header.)
Question now is, should I go with a 4" 6" or 8" IBeam? What iBeam size
would be equivalent to Three 2X12 at 13 feet??

Keep in mind, the only thing holding up the wall I plan on removing is
Two 2X12's

A specimen load for a 6X12 in wood beam at 13 feet is 200lb per foot
uniform loading, for which the max deflection is 0.1 inch This has a
safety rating of X2 to failure for reasonable assumptions:
Youngs 1.5E6 psi limit stress 1.2 kips

A steel I beam: W8X15 deflects 0.09 inches for this load,
a W8X13 deflects 0.11 inches.
Youngs 29E6 yield stress 36 ksi

Respectfully

Brian Whatcott Altus, OK