Replace sagging Beam over garage door span

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Old 04-28-13, 10:56 PM
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Replace sagging Beam over garage door span

The beam over the garage door opening has a sag (2 car garage). As you can see in the drawing the sag is affecting the all the structure above it.

My plan at this time, which is still in development, is to lift the joists off the beam using proper structural support equipment until the floors are level and the beam is no longer under tension.

Once I release the beam I would replace any load load bearing studs as required and replace the existing 2x12 beam(s) with LVL joists.

I am leaning toward LVL because, as I understand it, they are stronger than traditional dimensional lumber and the traditional dimensional lumber is failing. Granted it has taken 59 years to get to this point.

Please, somebody shoot holes in my plans.

I hope it is obvious I have exaggerated the effects of the sag.

 
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Old 04-29-13, 05:21 AM
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Welcome to the forum.

What material is the beam made of (wood or steel)?
What is the size of that garage bay door?

I'd recommend having a structural engineer review the beam before making any major movements on this.
 
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Old 04-29-13, 06:25 AM
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I second Mike's recommendation! Proper procedures must be used to prevent damage. It would be bad enough to have that portion of the house collapse, even worse if you are under it
 
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Old 04-29-13, 06:33 AM
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You did not even tell us the span so it's impossible to guess what is appropriate. In my area any use of Engineered lumber like an LVL requires an Engineer's signature. Most manufacturers will provide you the required documentation with the purchase of your beams. My inspectors will accept standard dimensional lumber without engineering support if it falls within the standard span allowances/tables. But most long spans can't be done these days with traditional dimensional lumber.

Your situation is not as easy as it may sound. You have to carry the weight of the living space above the garage and the roof above it. It is further complicated because you need to know the roof span to know how much load that front wall is carrying. If your house is narrow front to back the load is less. If your house is very deep there's a lot more roof that needs supporting and in IL you have to consider snow loads.

With a two car garage I'd say you have at minimum a 16' span if not 18'. Two 2x12's are woefully inadequate and so would two 12" LVL's. I'm totally guessing here so do NOT use my guesses for construction but... Assuming a 16' span, 30 lb per square foot roof snow load, 12 lb/ft2 dead load and 40 lb/ft2 live load in the living space and your house is 24' deep front to back then you would need at minimum two 18" LVL's or three 16" LVL's. In both cases they are grade 2E LVL's. I'm thinking you need a structural engineer and a steel beam.

---
I have three LVL beam locations in my house. Two have a span of 18'. The one that only supports the roof load above is two 16" LVL beams. The other is two 18" beams because it also supports a floor of the house in addition to the roof. I also have a 22' span with a floor and roof above which required three 18" high LVL's. And, I'm in NC with much lower snow load requirements but as you can see nothing comes close to working with 12" high beams.
 
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Old 04-29-13, 06:45 AM
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A few of the newer construction homes I've been in that have the garage as part of the house (with living space above), have used steel beams across the top of the bay door opening.
This may be the requirement in your case.
 
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Old 04-29-13, 05:41 PM
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As I look at your drawing, I am picturing that the garage door and the windows are not directly above one another. It looks like there is a roof over the garage, and that the windows are actually 8 feet or so behind the garage door opening? If so, there are surely 2 separate headers. The one above the garage door, and the one directly below the wall the windows are in. You'd need to beef up both of them, and getting a structural engineer in there to properly size your headers would be $$$ well spent. You have a LOT of roof load on that wall.
 
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Old 04-29-13, 08:06 PM
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I know I did not have all the required information in my initial post. I discovered this forum late last night, whipped together a drawing and made a post.

The house was built in 63 and has had no structural changes since birth, I have the design prints with some structural detail via a FOIA request.

I have not yet opened up all the walls and ceiling in the garage to get a better view of structure. The garage opening is 15' with 1 2x12 visible. I imagine there are 2 or 3 in there total but do not yet know for sure.

The windows are directly above and inline with the supporting beam. The roof line - between the garage opening and windows - is an overhang.

In regard to supporting existing structure:
A very good friend of mine owns a scaffolding and shoring business. His equipment is used to shore up structure of major facilities - imagine supporting the ceiling structure of a wal-mart, or airport terminal during an expansion. He has that kind of gear. So when it comes to supporting existing structure I am covered.

I will work with a structural engineer before any actual work commences. Until then I am researching potential options.

Thanks for the responses.
 
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Old 04-29-13, 08:34 PM
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To repair this will be a major undertaking, since this will require some real framing/carpentry skills and the entire end of that house will be unsupported once you remove that header. It's also dangerous if you don't support and brace it correctly.

IMO, the best thing to do would be to first off, identify which way the ceiling joists/floor joists run in the garage. If they run perpendicular to the garage door header, that would be a good thing, because you will be able to build your temporary wall under them to raise the 2nd story. If they run parallel to the garage door, things become a bit more complicated, as you'd need to install 16" OC blocking between the rim joist and the first floor joist before building any temporary support wall.

What you will need to do is first off, close the garage door and unplug the opener- then build a temporary wall (with a top and bottom plate) just inside the garage door. It can be a few inches to 12" away from the wall. The top plate will be secured to the existing floor joists (assuming they are perpendicular to the garage door header) or blocking (if the floor joists are parallel to the garage door header). Wall studs should be directly in line with the floor joists/blocking. As you build this temporary wall, you will want to try and raise the ceiling back to level. (theoretically, all your wall studs would be the same length if the garage floor is level) But you will need to do this slowly and gradually, since there are probably a lot of stresses involved in straightening something that took 50 years to sag. Starting your framing at each side wall, and gradually adding studs toward the center of the opening would probably be the best way to slowly "jack" the ceiling up with your studs that are all cut the same length (again, assuming the floor is level, and that the studs at each end wall would be of equal length).

Once the temporary wall is built and you've gotten it as straight as possible, you will want to brace the wall diagonally, and as you do, screw the diagonal bracing to every stud, straightening those as you go, in the event that they are bowed under the weight.

Once this temporary wall is built, you should notice "some" improvement. But like I mentioned, since it took 50 years for the house to sag, the bent lumber is not going to just bend back to be perfectly straight again. Your goal would probably be to just get the header straight again, and if you reroof or reside, maybe some of the remaining problems could then be corrected without worrying that it's going to sag again.

An engineer will size that garage door header correctly, but suffice to say that you probably want to get the biggest LVL that will fit in the space available. This may mean removing one of the top plates if you have a doubled top plate above your existing 2x12 header, so that you can get a wider/stronger beam. It's likely that your header will also need to be longer than the existing header, and supported by additional trimmers. Metal strapping across solid blocking on each end of the header may be required to tie in an additional 16" of framing on each side of the header.

Additionally, I would imagine that the siding on that end of the garage, and also the garage door jamb and trim/brickmould would also need to be replaced during this phase of the reconstruction. If you can swing replacing the siding above the garage, that would probably be a good idea as well. But it's probably optional.
 
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Old 04-29-13, 09:43 PM
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Identify which way the ceiling joists/floor joists run in the garage.

Perpendicular to the header.

Supporting the bracing the second floor.
As noted, I have access to the proper equipment to support the above structure. I will be using multiple 10k shoring frames (each section can support 10,000 lbs) that have screw jacks. Those will mate to aluminum I-Beams that actually support the floor joists. I imagine I should block the joists so they can fold over in this process.

This is similar to the 10k frames I will be usin


Your goal would probably be to just get the header straight again, and if you reroof or reside..

I intend to have a new roof put on this year. Obviously, I intend to complete this project before a new roof. It also became apparent I will need to pull off the existing siding around the garage opening and the windows above. Thankfully those sections are completely different than any other section of the house - I don't have to match existing siding.

An engineer will size that garage door header correctly, but suffice to say that you probably want to get the biggest LVL that will fit in the space available. This may mean removing one of the top plates if you have a doubled top plate above your existing 2x12 header.

This is where I may be extremely lucky. It appears I have a triple plate above the header. And to your first point, I do want to get the biggest LVL I can in that space, if not two of them.

The interior of the garage will be torn down to studs for this project so any questionable studs or sill plates can be replaced, new circuits pulled, and all new insulation installed.

For a bit of back story. I just bought this house a few months ago. First year I intend to deal with structural/functional issues; garage beam, roof, yard drainage, replace existing electrical panel, install sub-panel in garage, run new circuits. Once those projects are completed I will move on to cosmetics and replacements - windows, etc.

Some work will be hired out, some DIY.
 
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Old 04-29-13, 09:59 PM
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Sounds great. Best wishes, sounds like a job and a half!
 
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Old 04-29-13, 10:26 PM
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Nice post, XSleeper! I might add; if you need to extend the header a bay on each side for shear tie-in, as said, close the garage door and remove it. The spring may be a torsion type, be very careful, they can maim/kill. The back-hang track is connected to the opening jamb studs, may as well take it all apart. Read the safety on removing/replacing an automatic opener. May get by with leaving all track, just temp. brace in place.

The center wall sheathing between windows may require complete removal as it has bent/ripped wood at the fasteners in the years of sag. This will ease in jacking the assembly.

Here is a prescriptive load chart from on-line before you consult the S.E. for him/her taking the liability for your H.O. Insurance carrier, if ever a claim; http://www.parr.com/PDFs/LP%20LVL%201.9E.pdf

Gary
 
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Old 04-29-13, 10:34 PM
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I really do appreciate everyone replies thus far. Very detailed and thoughtful. It is the reason I eagerly started this post.

I am really weeks away from really getting into this project. what I may find myself doing is all of the grunt work then hiring professionals to come in and perform the actual removal and installation of the beams.

Over the next 10 days I imagine I will have all the drywall down in the affected area. I will then revisit this thread with a few photos and my findings.

Thankfully we are not in love with the existing siding so removing it for this project is not an issue.
 
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Old 04-30-13, 06:02 AM
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Well keep posting back with updates. I'd love to hear what the engineer recommends for a header. I really hope for ease and expense reasons that you have the height to go with LVL's since I find them easier to work with than steel.
 
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Old 07-19-13, 02:21 PM
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Update, beam installation completed.

Spoke with an engineer and it was decided a 5.25"x14"x18' PSL was be sufficient. A weyerhauser 2.0e PSL to be exact.

- Floor joists were jacked from inside and outside the garage (50" overhang) using six 20k shore frames and aluminum i-beams.
- existing beam removed.
- 2x6 sills replaced existing 2x4 sills
- 2x6 studs replaced existing 2x4 studs.
- New beam installed.
- Floor Joists lowered onto beam.

The result:
- Sag has been removed.
- Floors and windows above are level.
- I have a bunch of bent and ripped drywall to replace this winter in the rooms above.

I learned from a neighbor, in the 70's the previous owner had vertical siding installed on and above the garage to mask the sagging beam. This was after I pulled the aluminum off the soffit and found it was attached to wedge shaped strapping to make the soffit look flat.

Only took a day to pull and replace everything.

Now I am sheathing and finishing things off.
 
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Old 07-19-13, 10:41 PM
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Nice job! Thanks for posting back!
 
 

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