Deepest Header possible for garage door?
blownonfuel
| Posted in Construction Techniques on
Hello. Another newbie question from me. What is the deepest header that can be used over a garage 7′ garage door and an 8′ wall height? I would like to go with the deepest header I can.
Must the header fit under both top plates or can a section be removed from the lower one?
Thanks Again.
Replies
What width door ?
What is the load above the header?
Anyone needs those two questions answered before you can get an answer.
Headers transfer loads above them to the jacks, plates and foundation.
Size matters.
hello Dave.9' width door.4/12 hip, single story, no snow loads, asphalt shingle roof.
Doors on the gable end, or is it a hip roof ?
Two 2x10 for demensional lumber for a single opening will work.
2x10 is 9 1/4" plus double top plates will yield 12 1/4". leaves a 6'-11 3/4" opening. You gain the addtional 1/4" with the slope of the slap that should start 1" from the inside of the door.
I would flush out the 2x10s to fit same 3 1/2' demension of the 2x4 framing by sandwhiching a rip if 1/2" cdx plywood between them.
Another option is to use a parallam beam header that your local lumber company will size for you for both thickness and height. Ussually smaller than demensional lumber for a given opening and load.
Edited 6/25/2008 2:19 pm ET by DaveRicheson
Thanks Dave. It's a hip roof. I wanted to go with a LVL to begin with but was just wondering if I should go with the deepest one.They did spec. one out at 3 1/2 x 9 1/2 deep. Just wondering if bigger is better in this case.
Depends on what's above. Must know loads and how this area is framed. It is possible to bury the header up higher in some instances, but cannot tell you anything without more specifics. Also consider room from door hardware (track, opener, etc.)
Hello John. 4/12 hip, single story, no snow loads, asphalt shingle roof. Conventional stick framing in 2x4 wall.Thanks
How big is the garage? And what wall is the door in?There's no way to figure loads without knowing that.
It is dangerous to be right when the government is wrong. [Voltaire]
Hello Boss. Garage is 26'8" wide x 23'3" deep. There will be two 9' wide x 7' tall doors in the 26'8" wall separated by two feet.4/12 hip roof, single story, no snow load.
Wait a minute - We just covered this a couple of days ago.http://forums.taunton.com/tp-breaktime/messages?msg=106030.12
What do I know about sex? I'm a married man. [Tom Clancy]
Yeah Boss but I was wondering if I should go deeper. Is this a case of bigger is better? My local lumber yard has plenty of 11 7/8 deep lvls in stock but would have to order the 9 1/2s so I wondered about just getting the larger if they would fit.
In the other thread we talked about the 7 1/4" depth met the requirements, but showed an awful lot of deflection. I don't think anyone questioned the 9 1/2" depth. (based on what you told us) So I don't really see any need to go deeper. But of you want to, the cost wouldn't be all that much...
When more and more people are thrown out of work, unemployment results. (Former U.S. President Calvin Coolidge)
Using an example of a 24' truss span, I am coming up with a total load of 600 plf on the header (LL40, DL10). Deflection is 3/8" max. @ 4:12 pitch, non-snow for a 2-ply 9.25" lvl.
Thanks John for your help.
Thanks Boss, Yeah I just figured the cost difference is not that much for the larger LVL and they have them in stock I just was not sure if a 11 7/8 would fit.
If all they have in stock is 11 7/8, you can go with that. Worst case, if you run into any clearance issues, you could rip them down to 9 1/2".
Good idea. I think i'll pickup the deeper ones.Thanks
Two small doors don't require much of a header obviously, but what if some point in the future you decide that on big wide door would be better than two little doors? If you are going bigger, you might as well plan for a possible real scenario.
Size that header as if you were going to pull out that center support, and build it so you don't need it.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
If your hair looks funny, it's because God likes to scratch his nuts. You nut, you.
Are you in snow country? What is the span of the truss header is supporting? 9' is not all that much of a span, and I would think you want to minimize the depth to get your garage door to fit. I'm pretty sure 12" is okay from top of door to ceiling for mounting the track, and I've seen special hardware for shorter distances if necessary. I would think a 2-ply 1.75"x9.25" lvl would work, but you need to verify your exact roof loads.
Steel takes care of a lot of load if that is what you are worried about.
12 inches.. If you want to allow for trim 11 1/2 inches.
Thanks Frenchy.
Bottom top plate can be removed.
Bottom of header should be 7'-" above floor.
If by 8' wall you mean top of floor to top of top plate, that leaves 10 1/2" for a header.
If you don't want to wait for them to order a 9 1/2" one just rip an 11 7/8" down.
Thanks Mike. So the bottom top plate can be removed, does the code allow this?
My code book is at the office (and I'm not there right now) but while I don't think it specifically allows it, as long as the topmost plate either spans the header or is nailed to the header well in from the ends I've never had a problem with an inspector doing it.
Maybe if your inspector didn't have a lick of common sense he would fail you but it seems clear that the lower top plate is redundant with a solid header below. At least in this case. There are situations when you would want the double plate to remain intact.
Thanks again Mike.
I'm confused why you would need a top plate at all if the header was well connected to the rest of the top plate. When I raised my garage roofline, I put two 2x12 on edge on top of the existing top plate (with seismic connection down to the foundation).Rebuilding my home in Cypress, CA
Also a CRX fanatic!
If your hair looks funny, it's because God likes to scratch his nuts. You nut, you.
Code requires it, and it keeps the wall straight.
So a 2x4 is going to straighten out a 3.5" x 11.75" LVL header? How does that work?Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Save the Whales! and Guns!
Yes it can . Code also requires that design here as well.
They can't get your Goat if you don't tell them where it is hidden.
OK, can you explain how a single 2x4, knots and all, is going to do anything but be a nailer sitting on top of an engineered beam that is 3.5" wide but also nearly 12" deep. Really, what is that piece of lumber doing?
Are you sure it's code, or just the way you've always done it?Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Save the Whales! and Guns!
No here it is code, (well under some circumstances) The function as they give it is two act a tie across the entire front of the garage locking the side walls in. Now I have used a 2 x 4 to straighten a bowed LVL header just as you describe. LVL is actually quite easy to move in deflection across it's width. Took a more or less equally bowed 2x and set it with the bow opposite that of the header, a few bar clamps to pull it into place and off to the races.
They can't get your Goat if you don't tell them where it is hidden.
OK, I understand the "tie everything together" function of the top plate. But as this is a case of looking for maximum room with the header being the one solid piece, can't that tie be made using a different material, such as steel strap or plywood on each face. Heck, you could even extend it the additional 3' on each side and then just cut in the top plate from the other walls.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Save the Whales! and Guns!
There are ways around the issue, but that becomes a BI call.
I used to love messing with the inspectors and when it was a garage door in a gable end telling them I won't be using a header, just have the truss do it's job. Now that is tough to do here because of the new wind and seismic codes.They want the opening strengthened for sheer using the header. "Portal Frame" stuff.
They can't get your Goat if you don't tell them where it is hidden.
I agree Paul. The top plate is overrated. We have built hundreds of headers and cut them up two plates. Most of the bays we built always had the main header cut up both plates till 9' ceilings became common. Bob's next test date: 12/10/07
We usually build garages with 2x6's because they're often conditioned space and we want room for insulation.
But anyway, I finally got around to checking IRC2003 and they allow eliminating the top plate altogether provided the lintels are "adequately tied to adjacent wall sections with steel plates or equivalent."
The biggest problem I see with garage framing is not so much header/plate details and sizing, but that of shear transfer. Many of the garages built now have rooms above, some with multiple dormers, or at least attic storage spaces. With large openings below (overhead doors, service doors and windows) the weight becomes concentrated on smaller wall segements, which often times are overlooked and framed inadequately.
""Bottom of header should be 7'-" above floor."' I use 7' 1 1/2" O.F.F. for the rough header height.
That allows for a 2 x piece of material to be used as the garage door surround.
Width is always door called size + 3" for rough frame.
They can't get your Goat if you don't tell them where it is hidden.
Hello Dovetail. What does O.F.F. stand for? I read that you should frame the r.o. to the actual size of the door and then add the 2x to trim it out, this would give a overlap of 1 1/2" over the door edges.Thanks
O.F.F. = "Over Finished Floor"
Beauty is skin deep. But how rich you are can last a long time.
O.F.F. + Off Finish Floor, as someone else answered. Yes rough opening height +1 1/2" ,width + 3"
If door is 7h x 8w then then the rough frame opening is 7' 1 1/2" x 8' 3"
Surround covers the door by 1 1/2 on all three sides, that creates room for the tracks to be fastened solidly to trimmers and the weather strip to hide and protect the door opening.
They can't get your Goat if you don't tell them where it is hidden.
Thanks Dovetail for your help.
We use 3/4" stock, but 2x for inside casing for attaching the torsion springs.
1000' high headers might attract birds and need strobe lights.
Bob's next test date: 12/10/07
"1000' high headers might attract birds and need strobe lights."I saw one Jim at the lumber yard, it was on sale next to the left handed
screwdrivers and metric crescent wrenches.