Unsure of sizing for clear beam span

[96PSD]

Going to build a loft in my pole barn. I want it to be 26' x 7'-6". I want to have one center post at 13'-0". I plan to do joists at 16" centers. This is strictly a storage loft, nothing to crazy heavy as I have to be able to carry it up to it.

I want to use either a 6x6 or steel support column for the center post, what size 2x and either double or tripled up could support this span. I was thinking a double 2x8 or tripled. I am assuming I can not get away with a double 2x6 with a 3/4" ply sandwiched in between. The beam calculators confuse me a little because they are geared for a living space live load versus a storage dead load configuration. I have limited height above hence why I am trying to limit the beam size underneath. My workbench area is gong to be underneath the loft area.

 

[pattenp]

I think triple 2X8's would be okay but I would use triple 2X10's to just cover my heavy *** crawling up there.

 

[Chuckster in NJ]

I did mine with TJI’s....... Check the span calculations and use 40# for the load.

 

[mike93lx]

Off the cuff, I would do a triple 2x8, then probably 2x8 for the floor joists since it is under 8'.

Double 2x8 beam and 2x6 joists would likely be my minimum.

Beam and joists don't have to be the same size and you can always hang the joists at the bottom of the beam to maximize headroom above.

Glue and screw the subfloor to have it help as much as possible

How are you supporting the beam on the ends? Hopefully bearing directly on top of a post and not attached to the side of one of your poles

 

[96PSD]

I plan to put posts on each end as well. I am going to be sandwiched between a 10x10 clean room we have for bee keeping stuff and the end wall of the pole barn.

 

[mike93lx]

If you got the right sized lvl you could clear span that whole thing. Height won't matter as it won't detract from headroom in the mezz

 

[96PSD]

My total height of the room floor to ceiling is 12'-8" . I wanted about 6'-6"to 6'-9" clearance under the loft to walk around at my workbench. That is why I am trying to squeeze out the thinnest profile beam I can so I do have to bend over too much above to move around. I am 6'-0" tall.

 

[pmiranda]

Grade 1 Pine can probably do it in double 2x10's but I don't know how much stuff you want to put up there:
http://www.southernpine.com/app/uploads/SS_1-6L.pdf

Might be a good idea to put a footer under those posts. What's the slab like?

 

[96PSD]

I have a 5" slab with fiber added. 6" of 3/4" clean compacted below than on virgin earth.

 

[mike93lx]

My total height of the room floor to ceiling is 12'-8" . I wanted about 6'-6"to 6'-9" clearance under the loft to walk around at my workbench. That is why I am trying to squeeze out the thinnest profile beam I can so I do have to bend over too much above to move around. I am 6'-0" tall.

Your beam could be 2 feet tall and it won't impact headroom

Place the bottom of the beam at the height you want and hang the joists so they are flush with the bottom.

 

[TRWham]

Your beam could be 2 feet tall and it won't impact headroom

Place the bottom of the beam at the height you want and hang the joists so they are flush with the bottom.

This is a winner. Beam stiffness increases rapidly with depth so deeper beats thicker every time.

 

[96PSD]

Ahhh,, I see, never thought of it that way. Then I actually could have a built in toe board on top so things don't roll off as well. Thanks for the information and enlightening.

 

[bczygan]

You may as well go 8' instead of 7'6".

Decking: 3/4" T&G Ply with staggered joints glued and screwed.
Joists: 2x6 #2 and better Hem-fir at 16"o.c. Designed for 40#live load and 10#dead load L/360. Can span up to 9'1". Use joist hangers on beam and ledger boards so joists are in the same plane as the beam.

Beam choices to keep the depth as shallow as possible for maximum headroom means the choice is between steel and LVL's. I will calculate for an LVL as it is easier to install. The second choice is whether you want clear span to eliminate a column or not. I will calculate both ways.

With 8' joists the load/LF on the beam will be 200#/lineal foot.

For a beam supported by a column in the center, using a 13' span, a 2 ply 1 3/4 x 7 1/4 1.9E LVL will support the load at L/360.

For a beam that clear spans with no column, using a 26' span, a 2 ply 1 3/4x16" will work with the same calculations and loads.

4x4 columns will work to support the beam.

The 40#/SF LL and 10#/SF DL is a standard residential construction floor load.

These lumber specs are for standard lumber available from big box stores like Menards and the others.

If you keep 6'9" clear under the beam/joists your beam will stick up above the plywood decking by 1/4" for the 13' span and 9 3/4" for the 26' span.

You will have 5' 5 3/4" height in the mezzanine.

Don't forget to size the ledger board for the same loads, based on the spans it has, and properly support and fasten it to the building structure. Here you could use dimensional lumber depending on the spans.

I would advise using full length beams for either method. The 7 1/4" LVL's will weigh 93.6 pounds for each ply. The 16" deep ones will weigh 208# per ply.

Understand?

Bill (Designer)

 

[96PSD]

Bill,

Thank you for all the information. I came across some Aluminum I-Beams that I may be able to get. You seem to have a lot of knowledge of load capacity. Here is the information about the I-Beams. Do you think these could work?

3.5 inches wide, 4 inches tall, 1/4 inch thick. 13.5 and 15.5 ft lengths

 

[mike93lx]

Bill,

Thank you for all the information. I came across some Aluminum I-Beams that I may be able to get. You seem to have a lot of knowledge of load capacity. Here is the information about the I-Beams. Do you think these could work?

3.5 inches wide, 4 inches tall, 1/4 inch thick. 13.5 and 15.5 ft lengths

I would be interested to hear a real answer but my guess is no, plus how are you going to attach the joists?

Wood really is the right answer here, IMO

 

[bczygan]

Bill,

Thank you for all the information. I came across some Aluminum I-Beams that I may be able to get. You seem to have a lot of knowledge of load capacity. Here is the information about the I-Beams. Do you think these could work?

3.5 inches wide, 4 inches tall, 1/4 inch thick. 13.5 and 15.5 ft lengths

No, sorry, they won't do it.

Bill