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Garage Door Header Replacement

14K views 7 replies 4 participants last post by  gregzoll 
#1 ·
I have a raised ranch house, built in the 1970's and I am looking in to replacing the header over the garage. The garage is located in the basement level of my house with the main level being over the basement. I noticed that the header over the garage door has sagged about an inch in the middle. The header is currently constructed out of (4) 2x10's sandwiched together. I have been looking at lvl beams online and I am having trouble finding sizing information based upon the dimensions that I have. The current header is 17' long. The span tables say that I would need like a 3 1/2" wide by 16" deep beam. How would I do this with lvl's that are 9 1/4" deep, so that the new beam will fit in the same area the old beam used to be? For all you house framers out there, what is industry standard for this instance? I have heard that (2) 1 3/4" x 9 1/4" lvl's will be more than enough to support this load. I have full intentions of consulting an engineer about this, but I wanted to see what some other professionals thought. Any advice would help!
 
#2 ·
My question is; is the sag in the header actually causing you any problem?
I just think that if the sag is not causing a real world problem why spend all that money and time to fix it?

I have seen houses around here in the Old Towne district with front porch headers that sag a good 2" in 18' and have held up for 100 years without real problems.

Andy.
 
#3 ·
It hasn't caused me any problems other than the fact that my wife's SUV lacks pulling into the garage by about a half an inch. Plus, this sag has translated into the upper story and made the window jambs uneven, you can tell because the pressed board siding has saw-toothed over the garage door opening. I am hoping to replace the windows in my house soon and would like to get the house jacked up and the beam replaced so that my new windows fit square in the openings.
 
#5 ·
Problem is, replacing may not solve the problem. I would bring in an engineer to find out why the house is sagging. It could be due to undermining of the footing on one side, or both. Worst case scenario is, if they come back and tell you that the only way to fix, is by placing a lally column to jack that part up, and in turn not be able to use the garage anymore, until properly fixed. Also, they could spec out jacking the house on that side, and having a steel beam put in, vs wood.
 
#6 ·
I am not certain how you determined that the beam sags one inch. Let us assume your measurements are correct. That corresponds to a d/L (deflection over length) of approximately 1:200, which is not too far off the standard allowable deflection for a structural beam not supporting a floor. In order to reduce the deflection to 1/2 inch or less, which sounds like it is necessary to allow the SUV to get in, you are almost certainly going to need a steel beam. Steel is likely a good solution here because you can size it to be less deep than dimensional lumber or LVL, which will give you more clearance.

In any case, your engineer will be pleased to design the beam, draw up the plans so you can get the permit, and develop the support details required by the contractor to install it.
 
#7 ·
I determined the sag by measuring from the slab up at both ends of the header (they were the same measurement) the I measured from the slab up to the header in the middle of the span which was an inch shorter. There are some other houses in my neighborhood that have the same issue. Personally, I think that the contractor that built these homes in my subdivision skimped out on the header (2x10 in lieu of 2x12). I don't believe it is a foundation issue. I have thought about using a steel beam to correct the issue as well but I wasn't sure about the cost comparison between it and engineered lumber.
 
#8 ·
The problem with taking measurements, without using some kind of string, or marking as known level, the slab could be uneven. Only place that I know that has a true slab with zero variance, is the runway that was built for the shuttle down in Florida. Never trust the floor to be completely level.

I bet if you went back and used either a laser level, or string leveled, you will find an error in your measurements.
 
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