Standard spans for residential construction 3

[Beggar]

I'm under the impression that there exist standard tables that define permissible spans for beams of various dimensions.

* Is that true?
* If so, where might they be found?
* What kind of loading & material properties do they assume?

What I'm specifically interested in are things that would apply to a free-standing or partially attached patio cover or shade structure.

 

[pmkPE]

Check the associated section (wood framing) in the international building code; therr you will find prescriptive lengths for various spans and cross sections.

 

[boo1]

Some links are:

http://www.southernpine.com/tables/index.htm

http://web.usna.navy.mil/~greg/en442/files/NDS Tables.xls

 

[damstructural]

Here's a handy span calculator for joists and rafters from the American Wood Council. It won't do beams, but its cool.

http://www.awc.org/calculators/span/calc/timbercalcstyle.asp

 

[Tmoose]

Our Massachusetts state building codes have tables for floor/ceiling/roof joists that define permissible spans based on wood species and intended use.

I think the town building inspector compared my spans to a table based on the Mass code.

The spans were first limited by stress in the "extreme fiber" (top and bottom joist face). Then, if a drywall finish was to be applied, the deflection at max load was less than span/240 to hopefully keep the drywall from cracking. In the unfortunate case a flat roof is planned I think the deflection was limited with the intention to prevent a run-away load situation from "ponding."

 

[boo1]

I have an Excell perlin spreadsheet is you want it.