Steel Trusses

vpapai · #1 01/14/14, 12:10 PM

Thinking about using steel trusses for a pole barn type garage. Looking at 50 foot long by 26 wide. Want to make it two story so we could have storage/living space above. Planning to store the RV on one side, and tractor and equipment on the other.

Trusses would span 26 feet, plus would like to have about a 3 foot overhang on each side, as well on the front and back.

Anyone have experience using these rather than wood roof rafters?

Something along the lines of the ones on this site. http://www.buildyourown.ws/garage-ki...l#.UtV9fLQqeSp

Darren · #2 01/14/14, 12:37 PM

Those aren't the ones you'd need for a second story floor. Depending on the layout below, you'll need a hefty header over any opening for equipment access. You'll have to go with larger vertical columns (poles) too. You'll also need a way to brace the trusses to resist side loads. You can't just bolt them to a top plate.

I'm interested in others' suggestions or experience. I've thought about doing something simila rin the past. I was looking at a steel frame building instead to avoid the complications.

jwal10 · #3 01/14/14, 12:37 PM

Why? Wood is cheaper, easier to work with and easier to insulate. I can see using them if your posts are steel or an open building but for housing, no....James

Darren · #4 01/14/14, 01:14 PM

I can see an advantage in load carrying capacity with steel. Unless you're going to have a library upstairs, it might be worthwhile to talk to a wood truss company.

jwal10 · #5 01/14/14, 02:30 PM

I have seen a lot of them for loafing sheds and commodity buildings on dairies with steel pipe posts. Closing them in becomes the hard part....James

NorthwoodsMike · #6 01/14/14, 03:01 PM

I'm not sure if this helps, but we used wood floor trusses on our house. Our build is 40x24, and the 24' is free span. The trusses cost about $2100 for this size per floor. It makes running mechanical/plumbing/electrical so much nicer. I know you asked about steel, but like the others said, it might not be necessary.

bigjon · #7 01/14/14, 05:07 PM

u'll need concrete footers,with steel uprights bolted at both ends (top&bottom)

travisn · #8 01/14/14, 05:29 PM

Quote:

Originally Posted by NorthwoodsMike

The trusses cost about $2100 for this size per floor.

$2100 for each truss??? or $2100 was the total for the whole structure, per floor?

NorthwoodsMike · #9 01/14/14, 07:17 PM

$2100 for all the trusses on the first floor. The second floor was slightly higher, but had some cantilevered dormers.

travisn · #10 01/14/14, 07:20 PM

doesn't seem too bad, did you quote steel beams?

NorthwoodsMike · #11 01/14/14, 07:51 PM

I didn't, but based on the cost of the steel supports I ended up not using, I suspect it would have been a lot more.

vpapai · #12 01/15/14, 07:33 AM

The trusses would only be for the rafters, not the floor between the first and second floor. I think the trusses would be quicker/stronger than wood rafters.

Darren · #13 01/15/14, 07:58 AM

They would be stronger. The problem is trusses aren't designed to be connected to wood. The way the load is transferred to the support is different. When sitting on a concrete block wall, they're welded to an embedded plate for a couple of reasons. You may have to weld plates on the ends to do the same thing to reduce the bearing pressure. You're not concerned about uplift for a floor. The bearing pressure may be an issue and you'll still need the connection to tie the structure together to resist wind loads.

Part of the benefit of using steel is to have a greater span between them. That means more weight at the bearing points than floor joists at a much closer spacing.

rod44 · #14 01/15/14, 08:16 AM

Why not use "floor trusses"? Here is my shed and the room above it. The floor trusses were not that much more than regular trusses. They are engineered to hold the same weight as a house floor. You could use these trusses over where you have your tractor and smaller stuff and a cathedral ceiling type truss where you need more clearance for the RV. Here are picts of the shed and the room above. I think my main level ceilings are 10 or 12 feet. Shed is 30 by 50 and you need a steeper pitch for the room above. Sorry I didn't have a pict of the shed without me in it.

NorthwoodsMike · #15 01/15/14, 08:28 AM

Quote:

Originally Posted by Darren

Part of the benefit of using steel is to have a greater span between them. That means more weight at the bearing points than floor joists at a much closer spacing.

Actually, this is true for all trusses, including wood. Steel probably just takes it a step further.

For what it's worth, my floor trusses are spaced 19.2 OC, when conventional lumber would have required 16 or 12 OC, plus support beams. I wanted free span, and the trusses weren't much different in cost than LVL's/I-Joists.

haypoint · #16 01/15/14, 08:34 AM

Local Township was gifted a building kit for the Fire Dept. Open steel span. The concrete footers had to connect, under the floor from side to side to hold the building from splitting. Cost more for extra concrete than a pole barn would have cost.

Mt son designs trusses. I think he'd suggest an attic truss, putting your second floor within the roof truss. 12:12 pitch or gambrel.

haypoint · #17 01/15/14, 08:38 AM

Quote:

Originally Posted by NorthwoodsMike

Actually, this is true for all trusses, including wood. Steel probably just takes it a step further.

For what it's worth, my floor trusses are spaced 19.2 OC, when conventional lumber would have required 16 or 12 OC, plus support beams. I wanted free span, and the trusses weren't much different in cost than LVL's/I-Joists.

Is that a misprint? 19.2 inches? Really? How can you build anything with truss spacing that doesn't match anything?

wy_white_wolf · #18 01/15/14, 09:02 AM

Quote:

Originally Posted by haypoint

Is that a misprint? 19.2 inches? Really? How can you build anything with truss spacing that doesn't match anything?

96" / 5 = 19.2"

If you look at floor trusses you will see that spacing quite often. More span than going with 24" spacing and cheaper than going all the way down to 16" and gives more room for ducting between the trusses.

WWW

rod44 · #19 01/15/14, 12:22 PM

Mine is 30 feet wide and there are no support beams other than the side walls. The trusses are engineered to handle it.

If you ever have a fire with something in your shed, you are better off with wood than steel. The steel will collapse way sooner than wood due to the heat.

rod44 · #20 01/18/14, 08:28 AM

My term was incorrect on my trusses. They are "attic" trusses not "floor" trusses. They cover a 30 foot wide building with no interior support poles.

Sorry