Beam sizing question

[Jeff922]

Hey everyone, now that my Victoria's project is winding down - just some trim work and some built-ins left (I'll be updating my thread and posting pics soon), I need to build a barn to go with it    I'm just starting the design process and here's my basic thoughts:  24'x34' approx., balloon framed 1-1/2 story, 12/12 pitch roof.  The first floor is going to be my shop and I don't want any lally columns in my way.  I will probably need to use some engineered beams (perhaps 2 across the width of the building?).  Can someone point me in the right direction?  I'm having trouble finding the appropriate span tables and calculating load etc.

[UK4X4]

you can get I-beams that will span 24 ft

Loads would be - what usage the second story would have ?

Living area
loft
storage

if you fancy a play

Forte 4.0 (free) software will do it for you- or rough out your plans and hit the local lumber yard- they will spec out your requirements with the manufacturer they supply

[RIjake]

Jeff,
We were just discussing this on another thread. http://countryplans.com/smf/index.php?topic=12824.0

Boise Cascade (and I'm sure other manufacturers) makes a 40 series that will clear span 24' with a 11 7/8" engineered I-joist.  Make sure that you get the proper series that will clear span your width.  The cheaper 10 and 20 series only span about 16'.

Check out the tables listed here http://www.bc.com/wood/ewp/guides-resources/guides/Eastern-Southern-US/Eastern-BCI---VERSA-LAM-series.html

When you get to that page click on the specifiers guide.  Hammond Lumber carries them.  That's where I got mine.

[Don_P]

There's no doubt on these 24' wide buildings but at 20' wide I do have a desire to know for sure.
UK if you still have forte on your computer would you run the 20 series at 40/10 psf, 16" oc with a 19'1" id clearspan (20' wide building). I think it works... I really hope it works at that price jump. We have a design in the last week from the supplier speccing these.

[UK4X4]

If the 20 series is the same as the Weyerhaeuser TJI210 series

the software says TJI210-117/8" passes physically- but they also have a happy people floor rating - which says it fails

Total load deformation was 0.587" in the middle
Live load deformation was 0.470"

Using a 23/32 weyerhaeuser EDge flooring

The software uses standard lumber - or their own products only

The floor report uses a percieved floor performance graph too- so it does the standard calcs- pass but the percieved performance it fails with the set point at 50% it scores at 33

[roadtripray]

but they also have a happy people floor rating - which says it fails

huh?  What is a "happy people floor rating?"

thanks,
Ray

[MountainDon]

I think that means that a floor joist/truss can meet code specifications but can have some bounce or vibration to it. Using a larger capacity joist/truss cuts down on the bounce or vibration and makes the people who own it happy.

[UK4X4]

http://www.woodbywy.com/products/software/tj-pro-rating-system/


Correct Don !

the two PDF's explain in more detail

[Jeff922]

This has been very helpful.  I'm trying to minimize my use of engineered products ($$$) as much as possible.  I was thinking of running a couple of engineered beams across the width of the barn (perpendicular to the roof ridge) and then just use standard 2x10 joists 16OC running parallel to the roof ridge.  This concerns me because of the snow-load "spread" force on my outside walls.  In other words, the only thing preventing the outward spreading force on these walls would be the two engineered beams.  This doesn't seem like a good idea to me.  The only reason I had this idea is because I recently saw a newly constructed 24x36 clear-span barn in Vermont built this way.  From what I can remember the two engineered beams were about 3" by 17" and all the joists were standard 2x10.  I'm thinking I should abandon this concept.  Again, I want to keep cost down - my labor is free.  Is the only alternative pricey I-joists throughout?  What about a beam running the entire length?   

[UK4X4]

whats the snow load ?

the software does beam sizing too

whats the length on the ridge beam ?

-whats the length of the floor support beams ?

[Jeff922]

Snow load is about 90psf.  The basic building is roughly 24'x 36'.  I doubt I can get a beam to clear-span 36' and support the entire LL and DL of the 2nd floor.  Oh, I should mention that this barn will be slab on grade (no basement).  I'm starting to think that clear-spanning the entire first floor isn't a good idea because I don't really like the idea of getting into a pricey I-joist situation.  I may just have to suck it up and learn to live with a couple of lally columns.

[UK4X4]

That snow load is quite high- the same as my house build

my house is 26 ft wide and 36 ft long

The ridge beam required would be pretty HUGE to support those loads and probably impossible fora header if you want an 18ft wide double door

I went with engineered trusses due to the snow loads and to spread the weight arround

mm The software fails all the LVL's glue lams at 35 ft for that snow load with tributery of 12'

even the 8 3/4" x 24" Glulam gets you 3" of dip with just live load
it will only let me do a 3 ply 1 3/4" x 24" deep LVL and that dips 4 "

the floor can be done relatively easy- its the roof thats the problem 28,000lbs on each post ....if you could find a ridge beam strong enough !

[Don_P]

If the 2 crossing beams are actually heavy LVL or timber trusses capable of supporting the floor and tension load on the bottom chord and the peak is capable of supporting the ridge then the thrust is taken care of and the ridgebeam is spanning 12' at a jump, a 3 bay frame
Somewhere here I have a pic of a 7' deep glulam. It'd probably get into your headroom pretty bad