Double Ceiling Joist

Rking

Hey Guys, My first post and I hope it comes out right!

24' X 24' workshop in MS. Concrete Slab. 14' Garage door on front. 2 48" sliding windows on each side. Solid back.

I couldn't get Metal I-beams so I decidec to build my own.

Question: Will double 2" x 6"/ 1/2" OSB divider on 24" centers spanning the 24' length support a small load without sagging. I'm useing typical Kiln dried Whitewood 2 x 6's from our local Lowes.

Thanks

tpolk

__________________
The older I get the better I was

HooKooDooKu

Doubled up 2x6s on 24" O/C is really just 2x6s on 12" O/C.

Span tables for standard No. 2 graded southern pine indicates the maximum span for 2x6 on 12" O/C is 19'6", and that's just for the absolute minimum for ceiling joists. If you want to actually do anthing with the space above, you need much larger wood.

http://www.southernpine.com/spantables.shtml

Daniel Holzman

I spent 8 months in MS after Hurricanes Katrina and Rita inspecting damaged homes. Back then, there was no building code for most of MS, and the one they had was rarely enforced. Net result, half the houses I inspected had been destroyed down to the foundations.

Fast forward to the present, there is a building code. You are supposed to get a permit. Your local code enforcement official will help you to understand what the requirements are for the particular type of structure you are building. You need to consider critical design issues such as hurricane clips for the rafters, plywood bracing for the frame, adequacy of bolts for the foundation. The span tables are just the start. I suggest you purchase a copy of the building code, review your plans for the project against the code, then talk to the building official about specifics for your local area.

Yoyizit

Doubling the 2by thickness to 4by doubles the stiffness. Doubling the height multiplies the stiffness by 8x.

Rking

Damn, This site is GOOD! I wasn't expecting a reply, but, I get THREE already. Thanks guys all sounds like some good advise!!!!

Yoyizit

Tell your friends.

xxPaulCPxx

There are times to DIY a beam - I did it for some garage attic space.

This is not one of those times. 24' is a pretty good open span. What you need is something called Engineered Lumber - basically a wooden I beam. Lumber yards have access to this, and should be able to tell you exactly what you need.

As an alternative, if you just need storage space over the door area, you could frame in a wall on either side of the door them build a narrower platform - say 16' wide - above that. This could then tie to the outside walls for horizontal stability - you could even deck over the 8' spans there for wall to wall storage space.

seeyou

I'm not sure I've ever seen a 24' 2x6.

xxPaulCPxx

You can buy them, but they cost nearly as much as two 20'ers!