What size of Beam???

[Jochen]

I'm adding a 24' x 24' workshop to my little 20' x 24' Cottage which I started building last summer. And I'm wondering what kind of center beam I need to support my loft floor in the workshop. Is a tripple 2" x 8" enough when I use a centerpost to support it or should I use a tripple 2" x 10" beam instead?

The loft floor will rest on 2" x 8" floor joists, 16" on Center.

Jochen

[PEG688]

 I like that,, the work shop bigger than the cabin . All about priorites       More info on the loft beam,,, will it , the beam,, be 12' or 24' ??  Loft 1/2 lenght ?    No splices in the beam if it's 12' ?        If it's only 12' loft / 12' beam I'd still go with the 2x10 , not sure I'd triple it , dbl should do in 2x10  Pick good stock in Doug Fir nail it two, one, two; spaced every six inchs, 16d nail. If head room is a big issue your local lumber yard should be able to get you a LVL / paralam that will be smaller but stronger . HTBH  ;)PEG

[Jochen]

Peg, the Beam will be 24' long. So I will have a complete enclosed floor upstairs. I want the extra space.     The workshop will also be ballon framed with 10' high walls and carry 12/12 pitched roof.  Like my 20' x 24' cottage.

Reason for my question is that I have several beams made out of triple 2" x 8" laying around.  

I hope to add some pictures within the next fourteen days.

Jochen

[PEG688]

When you make your beams , if they are laminated / tripled it's  better if you stagger the joints.   So for a twenty four foot beam you'd have  12' ,  12 ,outer lam  , , 6',  12', 6'  center lam , 12' , 12'  other outer lam .  Nailed as before mentioned .   And when I've done that there is a post under the joints . So three post .  The vera / parlam might serve you better .   This is from memory not a chart so I could be wrong    But for only one post I'm sure you( I would )  ( Read my tag line below , just the way I was trained [/i]taught ) should use engineered lumber . IMHO , HTBH  ;)PEG

[John Raabe]

I did a quick calculation on a built-up triple 2x8 beam (4.5"x 7.5"). Spanning 12' @ 1/240 deflection it can conservatively support 200 lbs per foot. If you use 30 psf for the live load (7 DL) of a loft then each foot of beam can carry about 5 1/2' feet of loft floor load. If you have joists spanning 12' with half the load going to the 6" wall and half to the beam you should be OK but about at the limit. (Since it is continuous over the post, the beam is a bit stronger and stiffer than a single span would be - this is not factored in.)

Use this only for estimation. Note that this is for a 1/2 loft. If the beam is loaded from both sides (full loft) you are considerably undersized. If you plan to load the loft as much as you might the lower floor this will also not be enough.

[Jochen]

John,

as always!!!! Many thanks. It is so good to know this forum and to get all the support  from the members and moderators.

Jochen

[PEG688]

  Another point , would be point loads, a post on level one,, should be reflexed in the crawl space .   Always try bring bearing back to mother earth / footings . Or insure the beam you point load can take it   .

     On a old farm house we worked on last year it was like they took a crawl plan , offset the first floor loads  , and went to a third , plan off set yet again on point loads .    Needless to say ever floor level was,, very un level   . all over the place up to 2 1/2 " off in one place in about 6 ' . The owner  now,, as a kid remembered it as a great place to roll marbles as a kid  .   But not so 8)for the house  
  Good luck , HTBH  ;)PEG  

[Jochen]

Oh, there is already a Bigfoot footing system and a Sonotube full of concrete waiting to help supporting the load.  

Jochen