Framing 20'x20' garage - Contractor Talk - Professional Construction and Remodeling Forum

carterarce · 09-28-2009, 08:05 PM

Homeowner wants an 18' door in a 20' garage with the door in a bearing wall. I know I am supposed to have 18" on each side of door. Having less than 18" on each side would leave the garage with less "torsional strength", right?
It's a tight turn into the garage and he wants to get as much room as possible but keep as much yard as possible. His other bidders said it's not possible but I know we only need 6" or so to mount the rails and I would love to find a creative way to give him a bigger door while retain the 20' garage size. Anyone seen this before?

I've done tons of interior remodels and I can deal with remodel-type framing and structure no prob., but new construction has always been my weak side. I'm drawing it with a 16' door and I'm sure during plan review I could get this question answered but I want to see what the community has to say.
Thanks!

**framerman** · 09-28-2009, 08:13 PM

The header part shouldn't be much of a problem, but the shear on the fronts of those doors will. You need someone to do some engineering on the panels for lateral resistance.

Something like this

http://www.strongtie.com/products/st...ngwall/cfs.asp

or engineered HD brackets

http://www.strongtie.com/products/ca...ldowns_wc.html

rjconstructs · 09-28-2009, 08:39 PM

Can you make the garage a little wider? If not, how about using 1/2" steel plating instead of sheathing for the front of the garage? Not having much wall space to work with makes it challenging.
rj

carterarce · 09-28-2009, 09:20 PM

Great suggestions.

1/2" steel might be excessive? :-)

I wonder if the inspector would let me laminate 3/4" plywood on that front wall inside and out with a poopload of nails.

Seems like adding a foot or special order a 17' door would be easiest. Or just a straight up "No-can-do" like the other guys. Giving them a couple options might get me the work!

Thanks!

**joasis** · 09-28-2009, 09:30 PM

What you need and an engineer will suggest is a "portal frame" I would not hesitate to do one, but then again, I have a lot of experience in this area. In a short explanation, this would work, but it will not be cheap. Think about an I beam....as the header, and then having I beam "legs", welded or bolted to the top beam, all of this parallel to the door opening, and box framed to cover. The legs would have to be secured by anchor bolts...large ones, since this frame "transfers" the shear load on the endwall (door opening) to the concrete and footing.

Hope this explanation wasn't too murky.

mics_54 · 09-28-2009, 09:30 PM

See IRC R602.10.6.2 Alternate Braced Wall Panels next to openings.

Kgmz · 09-28-2009, 09:49 PM

What you need is Simpsons new product, Steel Strong-Wall®:
Garage Portal Systems on Concrete Foundations.

This allows you to use the steel panel provided with your standard wood framing and header. They make a 12", 15", and 18" panels, plus add 3" for a 2x on each side, you could get by with 15" on each side of door plus 18' 3" for door rough opening. Building would then have to be a minimum of 20' 9" wide.

http://www.strongtie.com/products/st...p?source=swnav

ScipioAfricanus · 09-28-2009, 09:53 PM

The IRC and IBC as well as the Calif. CBC all have examples of "portal Framing" using the Simpson Strong wall but I think the min. width is 16" for one of those.

What I think you need in this situation is an engineered "moment Frame" of steel probably. But then you are talking about tieing this all in with a grade beam under the doorway.

Not a cheap way to go.

Andy.

IHI · 09-28-2009, 10:01 PM

Maybe to obvious but have you called the building office and talked to them about what's going on with customer wants and ask for their input in how to make it happen? We used to be able to get away with 2' side walls and they've since changed us to 2'6"...BUT we can go narrower and like you said it comes down to interior/exterior structural sheeting with a ridiculous nailing schedule...so personally i would start there FIRST and take the ball wherever you need to from that point on.

**joasis** · 09-29-2009, 07:19 AM

Everyone of us who responded to this probably reflected on what would we do?

Since I am in Oklahoma, we have to build to expect 80/90 mph winds, the code does not allow variances for say, infill building, sheltered by other structures. In my area, 10 pound snow load.....not a big deal. I have no idea what Minnesota may be like, but as Josh pointed out above, the code in your area will dictate the conditions that will make this work, or disallow it totally.

I was looking at the Simpson sheer wall panels, and they look great. I have never used them, but i would give thought to them if this condition came up for me, since the portal frame I described above would be expensive for a small garage.

carterarce · 09-29-2009, 07:32 AM

Great ideas. Some of the options described leave the space on either side of the door at 18" or building the garage at 21'.

I think the best thing is to draw it up and ask during the plan review but plan on a bigger garage or smaller door.

I got a lot out of this thread including the Simpson site and cracking my IRC open. Just goes to show it never hurts to ask.
Thanks again fellas.

**genecarp** · 09-29-2009, 07:39 AM

Where is the architect, maybe i missed something.

mics_54 · 09-29-2009, 10:24 AM

yeah! architect! since after all...it's about LIABILITY not functionality. It's irrelevent HOW it's built unless that stamp is on the plan or the OWNER accepts the liability.