Garage Door re-design question

[Adam R]

We bought a place that has 3 - 7' x 7' garage doors. The floor to ceiling drywall measurement is 10' 1.5". My thought is to make one door an 8' x 8' door and combine the other two doors into an 18' x 8' single door. The garage is open span so structurally, the wall with the doors in it has a good truss above it. For the 18' span, are 2 2 x 12's sufficient for a header or do I need to use some engineered OSB joists to create the header?

Also, my thought is go with a jackscrew type door opener. With the 10' 1.5" ceiling height, would you stick with the 8' tall doors or is there room to go with 9' doors? If 9 is feasible, then I might see if a 9' x 9' and a 9' x 18' door is available.

Thoughts?

Thank you,

Adam

 

[mcbooya]

Not enough info to spec the headers. Depends on load bearing, building span, snow load, etc. x3 2x12's were acceptable for a 9' door for me, so I went with LVLs which are easier. Ask your inspector and lumberyard for span tables and to tell you if you can remove those wall sections, there could be concern on braced wall area if you dont have 4' or 2' or similar on each side of the opening.

 

[jack stand]

Your new 18' opening (as you stated) has a truss above it. At this point your objective is simply to stiffen that span and provide a nailer for your jamb and trim materials. This stiffening is against horizontal loads like wind. 18' can be a special order situation for dimensional lumber at the lumber yard, especially for only 1 or 2 of them. I'd build some type of "box beam" to span it, possibly a couple of 2x8's (min) vertically with a pair of (flat) 2x6's to create a "box". If you have a 2x4 wall, think about engineered lumber, something designed to be used as a post comes to mind with a 3 1-1/2" dimension.
Parallam PSL Column is one of these engineered lumber options.

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It's hard to give advice as you'll need to increase the height of your non structural headers and the gets you into re framing the existing short walls between the truss (ceiling) and your new opening. It may be better to remove the whole wall below the truss and start from new.
Then there's the concrete, are there any foundation situations like openings in the foundation to accommodate the door openings?
A picture or 2 would be helpful.

 

[Jinks]

7' is a normal height for a garage door, but 7' wide is just silly. We don't know where you are but I doubt many vehicles or trailers are easy to get through 7' wide doors. Garage doors can be ordered in any size you need, but aren't stocked at your local big box store. Only you know why you want the sizes you stated, but I'd look at one 16' wide & one 10' wide. Both will be easier to get through, & can be made to any height that works for you.

As for the headers, you are going to have to look at what exists now. I doubt you have one header covering all three doors so there's probably supports between each one. Changing the size of the door will require changing the header & support. Doing that would probably be easier by opening the entire wall, placing support (I used steel), & installing a large LVL. BTW, is this single story, single story with attic, two story, two story with attic, or something else?

 

[Adam R]

I mis-spoke about the door size. They are 7' tall by 8' wide. There is nothing above the garage except trusses, but I've put some flooring up there to make it useable attic storage, but nothing overly heavy. I had a garage door contractor out today that seemed pretty knowledgeable. He recommended 8' tall doors and making one 9' wide and the other 18' wide. Double sided steel panels with foam fill. His price on the 8500W openers was $1000 a piece and I said I'd be providing those from Amazon for just north of $500 each. His price for the 2 doors with glass in the upper panel, installed to include the provided openers was just above $5000. Leadtime could be as long as 15 weeks which is disappointing. I will have to demo a small concrete stub wall between 2 of the doors and cut off 6 inches of concrete on the other 2 stub wall supports to make room for the 9' door. I think I'll use a microlab beam for the 18' span and re-use the other header and raise it 1 foot. I'll try to take a picture when it is daylight. Thanks, Adam

 

[Jinks]

If it gets you what your want, good. OTOH, I had a separate shop behind my last house. It was built with an 8' wide garage door. Since I used the shop to store & work on motorcycles it seemed to be a great idea. Then one day I decided to bring a trailer in for some work...it wouldn't fit! The trailer would, even the wheels, but not the fenders. I could get it in if I moved everything close to the door & angled the trailer as I forced it through the door. Just wasn't worth it! My minimum on garage doors is now 10' wide.........

 

[adsinnott1]

Here is some information on how I ended up cutting my stem wall that it looks like you will have to do as well. The cut and break saw made easy work of it.

Cutting Garage "Curb" Flush with Floor

I have a raised edge/ curb on all 4 sides of my detached shop, about 6" tall, except for where there are 2 french door openings. I am installing a 9ft wide roll up door where one of the french door opening is and will need to cut the sill plate wall/ curb about 3 ft to be flush with the garage...

www.garagejournal.com