Reinforcing a notched beam after improper field repairs 5

[mfstructural]

I'm looking a wood beam that's 19' long amd made up of 3 2x14s. actual depth is 13.5". the beam spans the garage and is parallel to the garage door and off the garage door by about 3'. there is a 3.5" wide x 4.5" deep notch in the beam to allow for the garage door chain and track to pass through. I know, whoever designed this and just cut the beam in the first place are interesting people to say the least. I ran calculations, as the beam is supporting prefab roof trusses that span 30'. there is a wall in the middle of the span which was not meant to be a bearing wall. when i run calcs for 25 psf snow and 10psf DL, I get a w=525 PLF. this is a moment of approximately 23,600 LB*FT. when i ran numbers on the full size beam (unnotched) I found it's capacity was 9,900 LB*FT. yet the beam was not sagging or had not cracked at the notch. this was related to a home sale. I designed a reinforcing fix for the beam, with a full plate on each side of the beam and a channel bolted to the bottom of the beam to increase tensile capacity overall for the beam. I didn't realize the there was a handle for the garage door and because of that they cut the channel. in addition to that they didn't install a full height plate. they only installed a n 8" high plate so it's pretty much entirely in the compression zone. and the channel is cut. I feel like the plate in the compression zone will aid in reducing the stresses at the notch, but I'm not comfortable or ok with it regardless. I am being asked for a fix and they are being difficult as they want to close on the house asap and have it setup. I came up with a solution to either install a full height plate or weld plates connecting the channels to the 8" plate. The client is obviously not liking that as he wont' get it done by tomorrow. One side of me says I am doing my best and I'm sorry but you have to install the fix, but I want to help him at the same time. So I was thinking of installing straps around the beam at 6" on center. They could wrap around the entire beam and be screwed into the side of the beam. It was my last choice after getting pushback from client. What are people's thoughts on this? I think it can work but I am not sure how to calculate the tension that the strap would have to resist.
Thanks,

 

[KootK]

1) I would find some sketches enormously helpful.

2) What would be the purpose of these straps if you installed them?

3) We're talking about 14" LVL, right?

 

[mfstructural]

I wish it were an LVL...it's a beam built up with 2x14s. Pictures attached. The purpose of the strap would be to prevent the beam from fracturing at the notch. That is my biggest concern.

 

[msquared48]

Eliminate the garage door opener, shoot the door opener installer, and do a proper repair by replacing the whole beam.

Mike McCann, PE, SE (WA, HI)

 

[mfstructural]

I agree!

 

[JoelTXCive]

This would not be cheap, but temporarily shore up the ceiling, and then replace the triple 2x14s with a W section. Maybe you could get a W8 that would work so that there would still be room for the garage door opener track.

Also, I think the beam might be failing already. Are the horizontal cracks at the top of the notch saw overcuts? or are they evidence of shear failure?

 

[KootK]

I wish it were an LVL...it's a beam built up with 2x14s

Huh, I didn't even know that 2x14's were a thing.

The purpose of the strap would be to prevent the beam from fracturing at the notch. That is my biggest concern.

I wouldn't consider the straps rigid enough to do that job with faster slip etc. At the least, I'd want to do that job with GRK screws etc up from the bottom

You might jack the beam up a touch and weld a tension strap across the notch, giving consideration to:

1) The thing as a whole has to check out.

2) Future maintenance on the garage door could be a problem.

 

[RWW0002]

I think a better use of the steel you put in would have been full length ≈8" deep steel channel on each side of the beam sized to carry the full load and connected adequately to get the floor load "in" and back "out" of the steel and into the wood beam at bearing ends (assuming the original beam works in shear and bearing. This is likely the best fix at this point also, although I don't think they are going to get it done by tomorrow..

 

[JLNJ]

Open the garage door, weld KootK's bottom tension strap across the notch, and never close the garage door again. Done.

 

[KootK]

Touche... Missed that.

 

[KootK]

Any chance the numbers would work on a pair of C9 sistering the thing either side? Span's probably a bit long for that.

Is there meaningful roof height above this thing such that you might do something up there? Short hip trusses? This would be pretty invasive.

 

[dhengr]

Mfstructural:
Can you actually fix that kind of stupidity, when they do the same wrong thing twice, and then wonder why that isn’t better? Your straps won’t fix anything that’s wrong with that beam. You can see the beam splitting right where you’d expect it to split, at the top of the notch. What did they think they were fixin with the channel and side pls., and how did your drawing show them to be installed? Why not install a new beam of the proper size and depth. Then bust out the conc. fl. slab and lower it enough so that the O.H. door and its operating hardware can all be lowered enough to install under the new beam, without a notch in the beam. Then, put in a new slab with a notch in it someplace, if they wish.

 

[RWW0002]

Based on the load and moment in the OP, the span appears to be in the range if 19' I would bet a pair of C9 beams (one attached to each side as mentioned above) could be made to work with the loading given as long as it is adequately connected to the wood portion of the beam to brace the section and transfer load. I am doubling down on this being the best fix.

 

[dauwerda]

Get rid of the existing garage door opener and reinstall the channel without the notch cutout as you intended. If they have to have an opener, have them install something like this,

https://www.amazon.com/Liftmaster-Mount-Garage-Opener-Package/dp/B00CUQ616O

which doesn't require the center bar and connection that is currently being used.

 

[r13]

Remove the door handle if the door is not to heavy to lift up by hand, then replace/reinstall the channel.

 

[XR250]

Honestly, I'm not in love with your original repair.
It appears you are cramming 1/2"Ø lags into the skinny side of a 2x14.
Bad idea in general and there does not appear to be nearly enough of 'em to develop the shear flow required.

 

[mc5w]

Here are the best solutions:

1. Install a garage door that rolls up into a box. These can be obtained with a power operator. These are commonly used where the ceiling is 1 or more stories above the door such as in factories or it is desired to keep the ceiling clear such as when there is lighting or drop cord for power tools. Then replace the beam with a new one. This is an extremely satisfactory solution and the least messy.

2. Install 1 or more steel I-beams.

3. Jack up the ceiling a foot or 2 and install new beams.

4. Lower the floor and the garage door and frame.

5. Solutions 3 and 4 combined.

I suspect that there is a general headroom problem so jacking up the roof might be a more satisfactory solution. Back in 4th-7th grade there was a 1 story house and one day the owners added a 2nd story.

Any time you perform surgery whether it is buildings or humans it will be messy and it will not be a fun. Unless, of course, you are taking out your boss' appendix. That might be a lot of fun.