• 100% Satisfaction Guarantee

StructuralEng, Consultant
Category: Structural Engineering
Satisfied Customers: 6751
Experience:  Structural Engineer
59685895
Type Your Structural Engineering Question Here...
StructuralEng is online now

# We purchsed 2 LVL's from Menards. Menards get their LVL's

### Customer Question

We purchsed 2 LVL's from Menards. Menards get their LVL's from LVL Global out of Quebec.
We got 2 of the 1 3/4" x 9 1/4" x 24' We sandwiched 2 of these together with a regular dimensional lumber of the same size in the middle.
We used this to make a king beam/ridge beam to span a 20 feet roof line.
The measurements going the length of the room is 30 feet , so rafters going out 15 feet on each side.
It is approximately a 5/12 pitch with the rafters being 18 feet long.
Will this king beam/ridge beam hold a 30# ***** square feet?
The answer must have a verified span load charts and the formula you used to get the answer and be acceptable to the building inspector, which is why we need this info.
If you can answer the question by tomorrow at 12noon, then I would like to "get an answer."
Submitted: 10 months ago.
Category: Structural Engineering
Expert:  StructuralEng replied 10 months ago.
Hello
Customer: replied 10 months ago.
Expert:  StructuralEng replied 10 months ago.
I can provide you with detailed calculations for bending, shear, and deflection as an additional service (not stamped), but that is not a basic answer. Let me know if you would like me to submit the additional service offer. If you accept, I will provide you the calculations in about 3 hours.
Expert:  StructuralEng replied 10 months ago.
Is the 30 psf the snow load?
Expert:  StructuralEng replied 10 months ago.
Are you able to see all of my responses?
Customer: replied 10 months ago.
I just need to know if the ridge beam built with the LVL's will be able to handle a 30# ***** square foot load. But I will need to know what span load chart you used and what formula you used to come to your conclusion.
The building inspector said he wanted informed answers, not opinions (which we have many that say it is acceptable). Menards is still working on getting the charts and answers also.The king/ridge beam is being supported by 6 x 8 beams at each end. If you need any additional information, please let me know.Thank You,
Joy
Customer: replied 10 months ago.
Is the additional service offer for the more detailed info at an additional service fee?
Expert:  StructuralEng replied 10 months ago.
It's for detailed calculations for the beam. I will say that it sounds too small
Customer: replied 10 months ago.
Ok, I see the snow load question.. I am assuming it is for max for snow load. It is going to be a ridged metal roof, so the snow will hopefully slide off nicely.
Expert:  StructuralEng replied 10 months ago.
Actually, I'm certain it's too small. Who said that was the right size?
Customer: replied 10 months ago.
Hmmm, even 2 LVL's together with the reg dimensional lumber in the middle?? I thought this would over exceed the requirements.. I know that one certainly would be under.., but the beam sandwich?? The guy in the construction business who is doing the work told us that it would be overkill, with the beam and the support of the 2 end walls.
Expert:  StructuralEng replied 10 months ago.
Two 1.75" x 9.25" LVL with a 2x10 piece of dimension lumber? As a ridge beam with a vaulted ceiling? It's not even close.
Customer: replied 10 months ago.
I will add that I am only using my non engineering common sense, with no training and obviously misinformed on the strength of the LVL's. This is why I am wanting an answer for the span load charts and formula. As I said, Menards is working with LVL Global to get those tomorrow. I happened to see just answers when I was googling span load charts for LVL's. I really should have just waited for tomorrow for Menards, but was being impatient.
Expert:  StructuralEng replied 10 months ago.
There is no way any span chart can say it works.
Customer: replied 10 months ago.
Are you saying that there is not a chart to use, or are you saying that the span load chart will definitely say it does not work?
Expert:  StructuralEng replied 10 months ago.
I'm saying if they produce a chart that says it works then they made it up. It dials deflection for a 12 psf dead load and no live load at all
Expert:  StructuralEng replied 10 months ago.
Fails deflection
Expert:  StructuralEng replied 10 months ago.
It will deflect over 4" with a 12 psf dead load and 30 psf snow load. And that doesn't even include creep. Plus I would use 15 psf for dead load
Customer: replied 10 months ago.
Ok, so I will admit that I am not getting the answer that I wanted to get, but I obviously don't want my roof to cave in on the first big snow either! Are you getting your answer from experience or from engineering math equations?
Customer: replied 10 months ago.
I have some more questions regarding this ridge beam,. Is the fee still the flat fee of 45\$
Expert:  StructuralEng replied 10 months ago.
I used equations to get the deflections.
Expert:  StructuralEng replied 10 months ago.
Would you like me to size the proper beam? I can do that as this question. If you want the detailed calculations, I will submit the additional service offer
Customer: replied 10 months ago.
The frustrating part is that we have the king beam up already. At least there are no rafters or roof on it.
we have 2 of the 2 x 12 x 24 LVL's. Would this work for the Ridge Beam?
I (in my lack of engineering and building knowledge) don't understand how regular dimensional lumber can be stronger than the LVL's that are supposed to be known for their strength, straightness and durability.
The beam sizing would be nice. I won't need additional calculations, thank you.
Expert:  StructuralEng replied 10 months ago.
I will give you two sizes of LVL only. Mixing LVL and dimension lumber doesn't make sense. You won't get the strength out of the LVL because the dimension lumber will fail first.
Expert:  StructuralEng replied 10 months ago.
I will give you a size for L/240 deflection (bare minimum) and L/600 deflection (what I use when sizing a ridge beam to minimize thrust on the walls.
Expert:  StructuralEng replied 10 months ago.
5.25" x16" for L/240.
7" x20" for L/600
Expert:  StructuralEng replied 10 months ago.
That includes creep deflection for a 15 psf DL
Expert:  StructuralEng replied 10 months ago.
Customer: replied 10 months ago.
We are having 6 x 8 beams go across at the top of the wall to tie them together. They are going across at 2 places the opposite direction of the ridge beam.
Customer: replied 10 months ago.
I dont understand the L/600 and L/240... so the 5.25 x 16 for L/240?
Customer: replied 10 months ago.
collar ties required in the top 1/3 of rafter for thrust on walls also.
Customer: replied 10 months ago.
I think I need to ask the building inspector for some kind of book with the local codes and more requirements listed. I don't want to be taking anything else down.
Customer: replied 10 months ago.