I’m building an attached garage, 16-3 x 27-4, wood frame, 15′ garage door. The walls to either side of the garage door are 6″ on the attached side and 9″ on the freestanding wall side.
The roof is a low slow roof, and there will eventually be a deck above it. The structural wall is the long wall (ie perpendicular to the garage door wall). Roof framing is 2×12 16″ OC, 3/4 T&G ply screwed 8″ OC.
Someone “suggested” that BOCA specs a minimum width for the walls adjacent to the garage door. Since that wall is non-structural (the entire load of the roof is carried by the perpendicular wall), I don’t see why this would be a problem.
Questions:
1. Is there a BOCA minimum wall width? What section of BOCA addresses this issue?
2. What is the minimum wall width? Does it apply to this garage, even though the wall is nonstructural?
3. If the wall has to be wider, any ‘tricks’ to fix it? The garage door is in, building is framed and ready for siding.
Thanks.
Replies
Yes, there is a minimum width. It depends on your wind and seismic zones. Call the building dept. and ask. The purpose is to provide shear resistance to prevent the building from racking. Other methods can be used, such as engineered shear panels or steel moment frames, but they generally require engineering. BTW, 6 ft. and 9 ft. don't sound like problems, but you still ought to ask.
Andy Engel
Senior editor, Fine Woodworking magazine
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
Inches, Andy.Heck If I know....
be some kind of tough getting outta the car, no?Remodeling Contractor just outside the Glass City.
Quittin' Time
Whadda ya mean?
Who actually parks a car in the garage??
:)
Heck If I know....
That's why I have plenty of room to pile the #### and park the cars. Planning is everything.Remodeling Contractor just outside the Glass City.
Quittin' Time
Organized,huh?
I knew there was something strange about you!Heck If I know....
Oooh, that might make a difference.
But it's not the gable end, either, so he should gain some racking resistance from the roof. Hope so, anyway.
Andy Engel
Senior editor, Fine Woodworking magazine
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
It depends on your wind and seismic zones
I seem to remember that either (or both, or neither--memory is like that) FHA or VHA was requiring a 36" minimum wall dimension on the end walls for shear at all garages. Seems like they wanted 24" between doors, too.
I'm still working out how the garage door wall is not load bearing, though. It might not be carrying much of the roof weight, but there's a bunch of structural things going on in that wall, particularly if it's an 18' o/h door.Occupational hazard of my occupation not being around (sorry Bubba)
Don't those minimums assume a wood frame wall? I saw an article in FHB one time about using a welded steel frame, posts and header, to provide racking resistance on a garage door wall.
Don't those minimums assume a wood frame wall?
Probably, but I have a less-than rosy mental picture of trying to convince the BI department in Podunk that the adoopted code which uses only the 36" width that it is also predicated on wood frame contruction . . .
Of course, that space sure is nice to have, so the doors would open on a person's ride, were same able to be parked inside . . . Occupational hazard of my occupation not being around (sorry Bubba)
You'd get a lot more racking resistance by simply cross-bracing the "ceiling".
I'd imagine a plywood floor in the attic would do a lot.Andy Engel
Senior editor, Fine Woodworking magazine
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
When you say "low slung roof" do you mean a shed-type roof or a low-pitch gable roof?
Either way, you'll need some sort of racking resistance. Diagonal struts at top plate height would work, but would need to be sized by an engineer or experienced contractor.
I just re-read your original post. Sounds like you have a lean-to garage with the door on the end wall (not the eave wall?) If that's the case, I'm with Andy--the roof should provide all the shear resistance you need. If the inspector says so.
Mike
Edited 3/17/2005 3:22 pm ET by mike maines
done.. it sounds pretty dreadful ..
in our wind zone i need 4' shear panels on each side
you 6" and 9" is kinda ridiculous..
and you're using a non-standard door anyways ( 15' instead of 16')
why not reduce you opening to 9' , use a standard door ( 9' wide x 7' high.... or 8' if you want higher clearance )..
that would give you a 4' aisle on one side and a 3' aisle on
the other ..
[note that standard overhead door hardware requires 14" clearance to the ceiling joists... 10" for low-mount]
you exterior elevation views will be much more pleasant and your house will have a higher resale value ( better curb appeal )
Edited 3/17/2005 8:04 pm ET by Mike Smith
I agree with Mike ont he appearance, ballanced design, and common sense things. but disregarding code specifics for a miontue, did anyone lese notice that he implies this garge is an attached structure? The buldingh it is attached to and how that attachmwent occours has a lot to do with the sheaar strength and lateral load resistance.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
yes.. i noticed that .. but our code doesn't care.. it still wouldn't be allowed
i know he's trying to gain access for a car and say a riding tractor.. i mean he can't get two cars in
but i think he's trying to get too much out of too little.. and the end result will not be pleasant...
i think ( code aside ) that if he wants a 15' door , he needs a minimum of two feet on each side..
so he needs 19'.. can't get it , so he should cut back on the door sizeMike Smith Rhode Island : Design / Build / Repair / Restore
I agree on the practical side of things.But when did you ever find a client who didn't want to push the envelope.I built one that was a one car garage - generously sized with a ten foot wide door and room on both sides, with steps up to the untility room entry to house.Last time I was there, he had two cars inside, and had removed the stairs set so youhad a two foot hike to get in the hosue, and a freezeer on the opposite wall. I wanted to scream.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
you shoudda..
" that's it !... i'll never work for you again.. no matter how much you pay or beg "
well, why not ?Mike Smith Rhode Island : Design / Build / Repair / Restore
It's the dark side of my individual property rights philosophy - he should not be allowed to own a house.....many reasonsAaragh!
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
The garage is a "lean to" design - the existing masonry house wall forms one long wall of the garage, the outside wall of the garage is wood frame on a block foundation. The "flat" roof slopes 1/4" per foot from the house wall to the outside wall. The garage door is at the end (short wall). The 2x12 joists run from the house wall to the outside wall and bear all the roof/floor weight. In that sense, the garage door end wall is nonstructural - it bears only the weight of the door. The 15' door installed is an extension spring door, so the wall bears only the vertical weight on the tracks - the spring weight and door weight is tied into the rafter framing.
The reason for the 15' door is that it will allow the garage to be used for two car to four cars (tandem garages are common here in Western Pennsylvania). A wider building would have been preferred, but the terrain of the lot made that economically unfeasible.
As I mentioned, it is an older neighborhood, with limited lot flexibility. The existing 9' driveway is on the lot line, and can't be expanded. Setbacks on the other side of the lot limit the location of the garage, so the net result is that a vehicle cannot easily enter the garage "straight on", without a lot of back and forth wiggling. So, the larger garage door will allow the car to enter the garage at a bit of an angle.
Another reason is to allow a wider opening to move shop machinery, projects, and materials into the garage. Larger projects such as a boat will be easier to move in and out with a wider opening.
In practice, the ability to enter the garage more easily is the primary reason for the door size. The garage will mostly be used for a single car and a shop.
As I mentioned, the door is already in, so I'm kind of committed. I rehashed these issues a lot before building the garage, but neglected to revisit this issue before installing the door. I've read BOCA fairly carefully and cannot find this requirement, so I'm trying to understand the real requirement and what part of the code drives it.
The inspector has not raised the issue, and the plans were approved for the permit issuance, so it may not be an issue. However, the inspector has changed, and the old inspector did not well document his approvals and inspections, so I really just want to understand what the code says, so I can have a response ready in case raises the issue at the final inspection.
If it does become an issue, it looks like a 12" steel moment wall could be installed on the 9" side, and would still look OK with the door. Any other ideas on how to 'fix' it if it becomes an issue?
Thanks for all your help and suggestions.
Anyone have any further ideas?
Engineering is really pretty cheap. I'm sure some solution is possible.Andy Engel
Senior editor, Fine Woodworking magazine
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig