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What beam do I need?
- Thread starter Bangon61
- Start date
your question is like asking, " I want to paint my car green, what is the formula to mix the paint.
You're going to need to add a bunch of detail like what are the other dimensions, what are you storing up there, etc... ,and likely you're best to speak with an engineer
You're going to need to add a bunch of detail like what are the other dimensions, what are you storing up there, etc... ,and likely you're best to speak with an engineer
nadogail
Well-known member
Asking about the size of the beam is almost like asking "How many pancakes will it take to cover a Doghouse?
There are too many variables in that equation for me to make a SWAG (Scientific Wild *** Guess).
There are too many variables in that equation for me to make a SWAG (Scientific Wild *** Guess).
Dagny
Well-known member
If you can put a post in the middle it will get a lot smaller. And you will have a nice place for an outlet or air hose
BD1
Well-known member
Call local contractors for estimates and see what they say. Why guess at it ??
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Sent from my iPhone using Tapatalk
firebirdparts
Well-known member
I agree it’ll be big if it’s clear span. It’s a simple calculation, but you have to tell us the dimension in the other direction. How long are the joists.
Oh of course. The distance from beam to wall is 14 feet. Would like to use hangers on the beam for the joists. And would like it suitable to be used as a mezzanine sweet later. Total area 14 by 30 feet. I should have included this info but forgot completely. Thank you
ace10
Well-known member
I hope Canadian feet are a lot shorter than American feet.
LX-Markham
Well-known member
An engineer. Probably the one that will be stamping the permit drawings.Is anyone able to tell me the size and kind of engineered beam I would need to span 30 feet?
speed bump
Well-known member
For a clear span doing nothing more than 5 seconds of looking at deflection tables and assuming a 40 psf loading I would start at a W14x22 and see what I could optimize from there.
p00p
Well-known member
A selection of Industrial Steel I & H beams affixed in parallel, but then the issue becomes where they rest.
RVDan
Well-known member
An LVL beam would be around 5.25” x 15” according to some old brochure that I have here when I was looking to add a second floor.
30’ engineered floor trusses might be less money
30’ engineered floor trusses might be less money
karoc
Well-known member
I believe that places like HD or Lowes may be able to answer your questions, if not maybe they can point you in right direction.
matt_i
Well-known member
You'd want to decide on a guideline for loading (40, 50psf).
And determine the mystery length of the loft (you've given the 30' width).
The beam has to hold 1/2 of the total load, as a distributed load.
Example, you are trying to size for a 30' wide x 10' deep loft @ 50psf. The total load is going to be 30ft x 10ft x 50 lb/ft^2 = 60, 000 lbs. Of which 1/2 is going to be held by the "ledger" and the other 1/2 will be held by the beam in question.
The 30,000 lbs will be distribured over 30 linear feet giving you a 100 lb/ft linear loading.
Armed with those numbers you or an engineer can do a lot more good in selecting the beam.
I would recommend LVL over steel any day of the week. Steel has to be fabricated (saw cut) within 1/16" and have connections that are designed to connect it to the wood (at the ends and every single wooden joist needs a pocket to fully-brace the top flange)
Contrast that to your LVL which cuts with a 7-1/4" circular saw and nails and screws together like wood, including sheetmetal joist hangers.
Steel is useful if you want to save headroom imo over the depth of a flat truss or LVL.
And determine the mystery length of the loft (you've given the 30' width).
The beam has to hold 1/2 of the total load, as a distributed load.
Example, you are trying to size for a 30' wide x 10' deep loft @ 50psf. The total load is going to be 30ft x 10ft x 50 lb/ft^2 = 60, 000 lbs. Of which 1/2 is going to be held by the "ledger" and the other 1/2 will be held by the beam in question.
The 30,000 lbs will be distribured over 30 linear feet giving you a 100 lb/ft linear loading.
Armed with those numbers you or an engineer can do a lot more good in selecting the beam.
I would recommend LVL over steel any day of the week. Steel has to be fabricated (saw cut) within 1/16" and have connections that are designed to connect it to the wood (at the ends and every single wooden joist needs a pocket to fully-brace the top flange)
Contrast that to your LVL which cuts with a 7-1/4" circular saw and nails and screws together like wood, including sheetmetal joist hangers.
Steel is useful if you want to save headroom imo over the depth of a flat truss or LVL.
gsmith22
Well-known member
the beam is only half of your problem. you are going to need columns at each end and footings underneath them for that kind of span and any reasonable load. I could easily size something, but I am sure any guidance would be misused in a heartbeat. call an engineer
this is not something HD, Lowes, or any contractor is going to be able to tell you with competency. I don't think you want wood here either as it will probably be a ginormous glulam or LVL likely creating a head height issue below it. think steel. probably will have to cut a hole in the side of your garage and slide it in from the side. But as I indicated above, you need a complete load path to the ground with columns and footings. your beam is only the beginning.
this is not something HD, Lowes, or any contractor is going to be able to tell you with competency. I don't think you want wood here either as it will probably be a ginormous glulam or LVL likely creating a head height issue below it. think steel. probably will have to cut a hole in the side of your garage and slide it in from the side. But as I indicated above, you need a complete load path to the ground with columns and footings. your beam is only the beginning.
Blickus
Well-known member
Not a question for a web forum. Need to check your local building requirements. Engage an architect and/or structural engineer to design and certify the drawings. A poorly designed beam & support structure will bring all sort of problems if it fails (insurance, code enforcement.....).
bczygan
Well-known member
Floor deck: 3/4" T&G plywood glued and screwed staggered joints laid perpendicular to joists.
Joists: 40#LL and 10#DL L/240. 2x8's #2 and better Hem/Fir at 12" on center with solid blocking at midpoint of span.
Beam: Contributing area of 7SF x 50#/SF = 350#/LF total load on beam. LL of 280#/LF and DL of 70#/LF.
A 1.9 LVL of 4 plies would need LL capability of 70#/LF and a total load of 87.5#/LF each.
4 plies of 1 3/4x16 will get you close at 62 and 85 @ L/360.
A 1.9 LVL of 3 plies would need LL capability of 93.3#/LF and a total load of 116.66#/LF each.
3 plies of 1 3/4x18 will get you 88 and 123 @ L/360.
Most mezzanines need as much headroom above and below and at spans like this, without a support to cut the span, steel is the answer unless you use the beam as a curb for the mezzanine to minimize how low it goes. Bolting a ledger to a steel beam is no big deal. And steel pipe columns will support it nicely with a base plate and maybe without even a pad footing depending on floor depth and reinforcing.
Advantage of the LVL is it can be installed one ply at a time and fastened together.
Adjustments in the grade or species of the dimensional lumber used for joists can get you a stiffer floor of L/360. And a stiffer grade of LVL can also meet completely the requirements stated above.
For steel a W14x26 works. Deflection of .96".
Bill
Price them both and make your choice.
Joists: 40#LL and 10#DL L/240. 2x8's #2 and better Hem/Fir at 12" on center with solid blocking at midpoint of span.
Beam: Contributing area of 7SF x 50#/SF = 350#/LF total load on beam. LL of 280#/LF and DL of 70#/LF.
A 1.9 LVL of 4 plies would need LL capability of 70#/LF and a total load of 87.5#/LF each.
4 plies of 1 3/4x16 will get you close at 62 and 85 @ L/360.
A 1.9 LVL of 3 plies would need LL capability of 93.3#/LF and a total load of 116.66#/LF each.
3 plies of 1 3/4x18 will get you 88 and 123 @ L/360.
Most mezzanines need as much headroom above and below and at spans like this, without a support to cut the span, steel is the answer unless you use the beam as a curb for the mezzanine to minimize how low it goes. Bolting a ledger to a steel beam is no big deal. And steel pipe columns will support it nicely with a base plate and maybe without even a pad footing depending on floor depth and reinforcing.
Advantage of the LVL is it can be installed one ply at a time and fastened together.
Adjustments in the grade or species of the dimensional lumber used for joists can get you a stiffer floor of L/360. And a stiffer grade of LVL can also meet completely the requirements stated above.
For steel a W14x26 works. Deflection of .96".
Bill
Price them both and make your choice.
gsmith22
Well-known member
if you have to ask, you need to hire someone. free advice over the internet is worth exactly what you paid for it
WNYflyer
Well-known member
What does 40#ll and 10#dl L/240 mean? Thank you.
40#ll = 40 psf (pounds per square foot) gravity design floor load. ll= LL= Live Load = transient loads, could be there could not, moving load, occupant load, snow, wind, seismic, etc.
10#dl = 10 psf (pounds per square foot) gravity design floor load. dl = DL = Dead Load. Dead load is essentially the amount of consistent weight that a building must support at all times. Non transient loads, in general in the case of a floor, the weight of floor construction and anything permanently loading it.
L/240, L/360, L/600, L/1000.........are deflection criteria as a function of a structural member's span (span = "L" in inches) and typically only apply to design live loads but you also can't get stupid with deflection due to dead loads. For instance an allowable live load (LL) deflection of L/240 = (30'x12" per foot)/240 = 1.5" maximum live load deflection allowed.
Last edited:
see pictures
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- Joined
- Oct 13, 2011
- Messages
- 259
What does 40#ll and 10#dl L/240 mean? Thank you.
40#ll means 40 pounds per foot live load meaning 40 lb load per square foot
10# dl means 10 lbs dead load or the structure weight itself
L/240 is for the deflection of the beam from the weight on it, usually in the center of the span.
casmurbax
Well-known member
try a Jim Beam.
Like others have said there is way to many variables to give you a proper answer.
Like others have said there is way to many variables to give you a proper answer.
I am merely looking at options. As there are more than one. Asking questions is how one learns. I will definately go see an engineer AFTER I find out the approximate price point I'm looking at. I thought asking questions is a good thing. Guess I'm not a know-it-all like some people. I like to learn. Here is a question maybe you can answer. Why do you feel the need to post on my thread if you have nothing constructive to say and instead basically tell me I dont know what I'm doing? Thanks for coming out
casmurbax
Well-known member
"Am building a mezzanine in my shop. Will be used for storage and maybe become a small suite in the future. Is anyone able to tell me the size and kind of engineered beam I would need to span 30 feet? Thanks"
People on here will help you out, asking questions is good. with the little information you provided no one can answer your question without asking more questions.
So are you looking to build your beam with wood or metal?
What about the joists? How wide will this be?
Will it be connected on the sides?
How big of a load do you plan using it for?
Are you looking to be using supporting posts or do you want that 30ft to be support free?
People on here will help you out, asking questions is good. with the little information you provided no one can answer your question without asking more questions.
So are you looking to build your beam with wood or metal?
What about the joists? How wide will this be?
Will it be connected on the sides?
How big of a load do you plan using it for?
Are you looking to be using supporting posts or do you want that 30ft to be support free?
I have provided most of that info in a previous post. The area will be 14 feet by 30. I'm inquiring about a clear span of 30 feet. Joists at 1 foot o.c.. either 2 by 8 or 2 by 10 joists with hangers. Future suite. I actually poured a deeper and bigger pad at 20 feet of the span to accommodate a post. Am just looking at options. Oh, the posts would be inside the wall pocket sitting on the foundation wall which is 8 inches wide. Thank you
bczygan
Well-known member
The detailed answer I gave him should be all he needs to find costs. It's designed like a standard residential floor loading.
Take it to any good commercial lumberyard and get a takeoff and pricing for materials. Do it for all wood and an alternate for the steel beam. Make sure they include columns, ledgers, hardware and misc. Only extras I can think of are a railing for the open mezzanine. Now, if he wants to enclose it, the weight of the wall over the beam needs to be added. Not a lot, but needs calculation.
Bill
Take it to any good commercial lumberyard and get a takeoff and pricing for materials. Do it for all wood and an alternate for the steel beam. Make sure they include columns, ledgers, hardware and misc. Only extras I can think of are a railing for the open mezzanine. Now, if he wants to enclose it, the weight of the wall over the beam needs to be added. Not a lot, but needs calculation.
Bill