Ask Mark

Sizes of Beams

Step By Step
More to come
More to come
More to come
More to come
More to come
More to come
More to come
More to come
More to come
More to come
More to come
More to come
Ask Mark a Question

Are You Building a Home, Adding On, Repairing or Renovating? Click the ask Mark a question link above and submit your question. It'll be featured here on the site in the subject category.

    © Mark Saville 2006  

What size of beam do I need?


GluLam or Steel? question: I am building a new house. My garage is 24'x24'which has a bonus room above. I want to use 2"x12" joists, What can I use as my center beam, I want to get away from having a center jack pole inside my garage. I can send prints... David

Hi David, Thanks for your question. Is your garage attached to the house or detached?



Actually we just did a detached garage for a new house customer that has a span of 26 ft and we incorporated the loft type area above right in the trusses so there was no beam at all. We used an 8/12 slope. It depends on your situation. If it's attached it makes it a little more difficult but give me a few more details and I can help you out with it.

trusses with no beam Also what kind of wood are the 2x12's fir, spruce and I would guess they're 14 ft long? Also what stage of construction are you at? Thanks, Mark

2x12’s = Top Choice #2 Southern Yellow Pine 12’ Long
I have the foundation complete, getting ready to install floor joists

Hi Dave, It's not possible to do it with a built-up beam maximum span for 5-2x12 is 12'-9". You can do it with a glue-lam. The size you'd need to do a clear span is 5-1/8" thick x 15" deep. Now to save on headroom you could send the beam up into the floor space and use hangers to attach the joists to the side of the beam. This works well we've done that a lot. You could also do it with a steel beam which is probably somewhat less expensive than a glue-lam. Size W10 x 22 which is about 6" wide and 10" deep. These figures are taken from my building code span tables which are more than adequate.




  Thanks for the information, it's been a big help. Please publish this, I hope it will help someone else down the line. David

  One more question. If I use the steel I Beam how would I attach the 2x12's to it, and how do I attach it on the ends to the walls?





glulam floor beams
Some heavy Glue Laminated Beams for the upper floor.

Hi Dave, The best way to do that is to have the steel company fasten a 2x6 to the top of the beam and then rest your joists on top with the beam below the ceiling. It won't take too much headroom. On the ends you build beam pockets in the walls for bearing using multiple studs to support the load. You can bring the top plates up to the 2x6 that is on the beam and then put a metal strap across the whole thing or just nail the plates in.



© Mark Saville 2006 Reprint with Permission only.

FREE Advice

Building a new home or addition? Need advice on Repairs? FREE monthly news and tips.Your personal information is NEVER shared with anyone.

Your Name:
E-mail Address:

Sponsored Links

Coming Soon