On Tue, 17 Jul 2012 13:30:23 -0500, wrote:

On Tue, 17 Jul 2012 00:53:45 +0000, 69roadrunner
wrote:


I am planning to build a porch roof attached to the back of my house. It
will have a trussed roof. The room will be 14' x 14'. I plan to support
this with one end attached to the house and the other two corners
supported by 6 X 6 pressure treated posts.

What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam will
support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Thanks,

I would not build anything with a 14 foot span. You'll get eventual sag
in the middle no matter what you use, unless it's a steel girder. Use a
center post. Seven feet is easy to span and much stronger.


Well yes and no. There is always some sag no matter what you use but
it can be designed within acceptable limits. He can also use knee
braces to cut down on the span if they aren't in the way.