built up beam

[astidham]

Hello all,
what is the best 2x for the buit up beam for a 20x30 single storey?
should the wood be treated?
Im using a pier foundation spaced per plans @ 7'6"

[MountainDon]

If you are building the beam foundation far enough off the ground to permit easy crawling under the building you do not need PT wood for the beams.

Is that of any help?

[Bobmarlon]

I think 2X10 would be fine  but I believe somewhere on this site I read you need 2X12 for an 8 foot span.  MY friend told me and I didn't know this but for built up beams you must nail both of the other pieces of 2X to 1 center piece so the inspector can see the nail heads on both sides.   I feel like you would get a really solid answer from someone if you posted a picture of your piers or gave more description how many Beams? 

[astidham]

Thank You MountainDon, very helpful!
And Bobmarlon, I havnt started the piers yet due to weather.
the 20 x 30 single story only requires 2 beams spread at 7'6" but Im using a center row of piers for a 3rd beam.
I will be using 2x12 for the beams

[John Raabe]

If you have the 1-story 20' wide cottage plans you have all the specs for the beam on the P&P Foundation plan sheet 1. It is called out in the upper right corner of the beam layout plan. That plan has a glu-lam option and a built-up beam option using 2x10s. For further information on how to build a built-up beam see this free report: http://www.countryplans.com/builtupbeam.html

If you will do a center line beam as well you will be taking half the floor load off each outside beam so they will be slightly overbuilt, but I would still build the same size beam. Note that the beam is sized to match the size of the posts so the metal connectors work properly. If you have the height be sure to brace the posts to the beams as shown (see Alternative Bracing detail).

[astidham]

Thank You John,
my plans do have this info but i dont recall it saying pt or not.

[John Raabe]

If the beam is more than 8" above the soil and is not exposed to weather it is not normally pressure treated. If you are in serious termite country it might be wise to check around for what you can do to protect the structure.