10'x30' Mezzanine Engineering Glulams

[472scout]

I'm about to order the lumber to build a 10' wide x 30' long mezzanine along the back wall of my 30'x40'x14' pole barn.

This will be for general storage. Extra car parts (not drivetrain), winter tires, misc. household goods, etc. The only heavy item I can think of is a 80 gallon air compressor. For a W.A.G. I'm going to say 3,500 lbs total. Mostly along side and walls.

Here's where it gets interesting. Naturally before I've had a chance to get deep into the research an opportunity to get a Rosboro "X Beam" 3.5"x9.5"x30' Glulam (or 2) for cheap has presented itself. I'm good with an single center post (no wall) to support the glulam, but any more than that is a non-starter.

So should I jump on buying one of these Glulams or is it too weak?

 

[Hank11]

There are charts for this application. Look at those and then look at the other possibilities on sizing to determine which suits you better.
My initial reaction is that two of the beams you offer might be just fine. But I’m not an engineer and you should not rely on random internet advice.

 

[472scout]

There are charts for this application. Look at those and then look at the other possibilities on sizing to determine which suits you better.
My initial reaction is that two of the beams you offer might be just fine. But I’m not an engineer and you should not rely on random internet advice.

Thanks. Using charts for the joists is simple, but I haven't found anything like that for glulam beams. At least not that I understand.

Using two of the glulams would be fine by me, but to maximize my headeroom I can't have the joists sitting on top of the glulams. I'm thinking I would use hangers to connect the joists to the beam.

 

[jkuro]

I think LVL is cheaper than Glulam.

Here's some info:

https://www.westfraser.com/sites/default/files/products/LVL/LVL%20Users%20Guide%20-%20US%20%20v0415.pdf

 

[472scout]

I think LVL is cheaper than Glulam.

Here's some info:

https://www.westfraser.com/sites/default/files/products/LVL/LVL%20Users%20Guide%20-%20US%20%20v0415.pdf

I'm getting a deal on ones that were ordered, but never used.

 

[Hank11]

I'm getting a deal on ones that were ordered, but never used.

this might come down to how much of a deal. If it’s a few hundred dollars to do this in a way that suits you better probably better off doing that.

 

[472scout]

this might come down to how much of a deal. If it’s a few hundred dollars to do this in a way that suits you better probably better off doing that.

I like that these glulams are only 9.5" tall. Just don't know if one of them would be strong enough.

 

[Skooterj]

https://www.fp-supply.com/cmss_files/imagelibrary/Glulam/Glulam%20Span%20Table.pdf

Glulam span chart, quick google search.

 

[472scout]

https://www.fp-supply.com/cmss_files/imagelibrary/Glulam/Glulam%20Span%20Table.pdf

Glulam span chart, quick google search.

Good find. Appreciate it.

 

[472scout]

Ok, am I reading this correctly. The 3.5"x9.5" glulam with a 16 ft span can handle 236 plf (pounds per linear ft). 236x16 = 3776. So it can support 3776 lbs?

 

[545_days]

Please don't be insulted by an obvious statement: Don't forget that the glulams also must support the joists, flooring, railing and live loads in addition to whatever your store. 11.6 lbs/ square foot for both live and dead loads sounds really low.

 

[472scout]

Please don't be insulted by an obvious statement: Don't forget that the glulams also must support the joists, flooring, railing and live loads in addition to whatever your store. 11.6 lbs/ square foot for both live and dead loads sounds really low.

If I can ask how did you calculate that? Are you taking into account that the load would also be supported by the back wall?

 

[545_days]

While I am an engineer, I'm not a structural engineer by training or experience, I'm not your engineer, and I turned to the dark side and became a manager over 25 years ago. In other words what I type below is not competent advice


I was assuming 3,500# divided by 300 sq ft on the basis that your 3,500 includes the dead loads from the joists, floor and plywood (which it probably doesn't) I also did not use any safety factor. I do believe that typical loads per square foot for a floor used for storage should be much higher.

Assuming 2x6 floor joists on 16" centers and 3/4" plywood which should be good for a live loads around 50# per sq ft. Your dead weight of materials not including railing is (guessing) 50# per foot. Assuming half the weight of on the live and dead loads is supported by the glulam beam and a 50#/ft^2 live load I would think you would want to support closer to 275#/ft of beam. (10' wide x 50#/ft^2 + 50# per foot for floor joists and plywood = 550 lbs. per foot with half supported by the glulam and half supported by the back wall.)

Of course I completely ignored seismic loads, wind, or any safety factor that a real structural engineer would include. Not because they are not necessary, but because I am not a real structural engineer.

 

[Kaizen]

I did a 4x36 mez. Used 2 center posts 6x6 and 2 at the end. Double 2x overlapping each other. I love it. I am glad i built it twice what i thought i needed. I made a mobile elevator which allows me to put all kinds of stuff up there that i never would attempt on a ladder. So overengineer it even if you need another post.

 

[472scout]

While I am an engineer, I'm not a structural engineer by training or experience, I'm not your engineer, and I turned to the dark side and became a manager over 25 years ago. In other words what I type below is not competent advice


I was assuming 3,500# divided by 300 sq ft on the basis that your 3,500 includes the dead loads from the joists, floor and plywood (which it probably doesn't) I also did not use any safety factor. I do believe that typical loads per square foot for a floor used for storage should be much higher.

Assuming 2x6 floor joists on 16" centers and 3/4" plywood which should be good for a live loads around 50# per sq ft. Your dead weight of materials not including railing is (guessing) 50# per foot. Assuming half the weight of on the live and dead loads is supported by the glulam beam and a 50#/ft^2 live load I would think you would want to support closer to 275#/ft of beam. (10' wide x 50#/ft^2 + 50# per foot for floor joists and plywood = 550 lbs. per foot with half supported by the glulam and half supported by the back wall.)

Of course I completely ignored seismic loads, wind, or any safety factor that a real structural engineer would include. Not because they are not necessary, but because I am not a real structural engineer.

I think your material weight might be high, but that is really useful.

A 50 lb live load for 300 sq ft would be 15,000 lbs. According to my math with one center post at 15 ft that 30 ft glulam can handle 8,880 lbs. Of course, it won't be supporting all the weight and I could also sister a 2x10 to it.

For material weight I found some calculators. 28 2"x8"x10' joists (on 12" centers) will weigh approximately 635 lbs and 3/4" plywood decking is 486 lbs.

2×8 Lumber Weight Calculator & Chart by Wood Type & Length

Comprehensive calculator and table gives the weight of 2×8 lumber by wood species and board length. 2x8 weights for pressure-treated wood included.

roofobservations.com

Plywood Weights, OSB Weights & More: Calculator + Charts

Calculator and charts for plywood weights, OSB weights and weights for MDF, MDO, and particle board. Charts have weights per standard sheet and per square foot.

roofobservations.com

That said, a 50 lb live load is considered on the low side for storage from what I've just been reading.

 

[CraigStu]

If you are going to use joist hangers be careful about glulams or lvls. Years ago I got a few 2ft cutoffs after a friend built his garage. I thought they's make some great blocks for something, sometime. Then I tried to use my circular saw to cut them. Dang things were HARD. I am not actually sure what they were but to screw something to them I am pretty sure you would need to predrill the holes.

 

[Hank11]

If you are going to use joist hangers be careful about glulams or lvls. Years ago I got a few 2ft cutoffs after a friend built his garage. I thought they's make some great blocks for something, sometime. Then I tried to use my circular saw to cut them. Dang things were HARD. I am not actually sure what they were but to screw something to them I am pretty sure you would need to predrill the holes.

Pay attention to this ^^^^^^^ You might want to add a piece of solid two by material to your beam to let you nail the hangers in or you might want to pre-drill and use hanger screws.

 

[stuartmichael95]

I'm about to order the lumber to build a 10' wide x 30' long mezzanine along the back wall of my 30'x40'x14' pole barn.

This will be for general storage. Extra car parts (not drivetrain), winter tires, misc. household goods, etc. The only heavy item I can think of is a 80 gallon air compressor. For a W.A.G. I'm going to say 3,500 lbs total. Mostly along side and walls.

Here's where it gets interesting. Naturally before I've had a chance to get deep into the research an opportunity to get a Rosboro "X Beam" 3.5"x9.5"x30' Glulam (or 2) for cheap has presented itself. I'm good with an single center post (no wall) to support the glulam, but any more than that is a non-starter.

So should I jump on buying one of these Glulams or is it too weak?

have you considered steel mezzanine? the company i work for designs, engineers and installs custom mezzanines for all applications

 

[LOW1]

Any building codes that you have to comply with?