I Beam for structural support

[MotorSeven]

If your rural, stop by and talk to your road super. They pull out old steel beams all the time when replacing bridges with the new "fancy" concrete ones. Some scrap them, others sell them at auctions, others let them go for free if you go haul them off.......... You never know until you ask.

 

[MotorSeven]

so you dont think my drawing on the picture will be sufficient? (assuming the beam is the correct size), starting to sound like this may be more trouble than its worth. Maybe I should just live with two poles as the support.

I think it's worth it, just size it properly and you won't have any problems. Like Crazyal said, wood trolley beams are in almost all of the really large barns here and have been operating since the 30's. I would use steel(today), but it shows you how strong wood really can be.

 

[GLyford]

You have a lot of vertical space there, which opens up a lot of options for you for a taller beam. I wonder if you could find a truss that would use less material but take advantage of more of that space? You'd likely have to brace it horizontally at several spots. I'm looking up at the ceiling of an industrial building right now and the whole flat roof is a crisscross of trusses about 3' tall. I've seen some for sale used, if you can afford to wait a little something might turn up near you.

 

[KennyG]

This is just a little "outside the box" thinking, but consider this. I'm not 100% sure why you have the existing columns. A ridge pole in a rafter roof doesn't take a vertical load. The roof load is passed all down through the walls. The ridge board distributes the horizontal loads between the two sides and prevents rafters from twisting. (I've seen old houses built without ridge boards. Scary but they didn't fall down.) Theorectically, you can build a rafter roofed building infinitely long with no interior posts. We use trusses on pole barns to make them easier to build and span longer, but the trusses aren't needed for vertical support.

If this building rafter system is too weak to transfer the loads to the outside walls, you will need the vertical support. If the ridge board is being vertically supported by the posts, the existing column span seems too large. If it was mine, I think I would add the i-beam and then build a wood truss system between it and the ridge pole, not just vertical supports. Still, the whole thing strikes me as odd. With this construction, it could have been a flat roof.

 

[GLyford]

I'm not 100% sure why you have the existing columns. A ridge pole in a rafter roof doesn't take a vertical load. The roof load is passed all down through the walls.

That's true if there are collar ties to keep the walls from spreading. If there are no collar ties, then supporting the ridge keeps the rafters from dropping at the ridge and pushing out sideways as they change angle. Kind of an either-or thing...some people do both.

 

[RoyJackson]

Hello, Iam looking for a couple opinions... I am planning to upgrade my exsisting pole barn to a shop/workspace...

I suggest you contact the manufacturer of the pole barn with your question. That would be the safest way to go.

 

[mjncad]

so you dont think my drawing on the picture will be sufficient? (assuming the beam is the correct size), starting to sound like this may be more trouble than its worth. Maybe I should just live with two poles as the support.

I haven't seen a roof supported in such a manner as you are thinking of doing; hence my suggestion to convert to a truss type system to support the roof, and just use the beam as a hoist trolley.

 

[mickd]

All pretty good advise, a 10" x 12 lbs per ft beam seems extremely light for your 30' span. When calculating you must factor not only your the span and the
dead load ( the roof itself )but live load ( roof + snow/ice + loaded trolley while at center span ), to properly size the member. If you're buying this iron new you may be surprised at the current prices.

 

[LD1]

I wish the OP (shibaura_4043) would get back with us.

Last question I asked was about rafter sizes and spacing so we can kinda reverse-calculate what that roof is designed for and go from there.

Upon further looking at it, it appears as though the roof isnt designed to hold much load at all. I dont recall wether he ever said where he lived, or what kind of snow loads can be expected??? But....

It "looks" like they are 2x8's on a little more than 4' centers He said his barn was 30x30, so each rafter is spanning 15'. The load table I just looked at for a measly 20psf live load lists 2x8's (no. 1 grade) max span of only 14' AND thats on 24" centers:confused2: So that span is over that, and will less than half of the required rafters....

Usually never see rafters more than 2' centers. Any mroe than that and its truss territory....

As to the beam and what will or wont work....can help without more info. And even then, our ability to help is limited. I'd try to find out who built the building, and it may be worthwhile to have an engineer take a look. Cause right now...I'm not liking the rafter situation from what I can see.

 

[mx842]

I wish the OP (shibaura_4043) would get back with us.

Last question I asked was about rafter sizes and spacing so we can kinda reverse-calculate what that roof is designed for and go from there.

Upon further looking at it, it appears as though the roof isnt designed to hold much load at all. I dont recall wether he ever said where he lived, or what kind of snow loads can be expected??? But....

It "looks" like they are 2x8's on a little more than 4' centers He said his barn was 30x30, so each rafter is spanning 15'. The load table I just looked at for a measly 20psf live load lists 2x8's (no. 1 grade) max span of only 14' AND thats on 24" centers:confused2: So that span is over that, and will less than half of the required rafters....

Usually never see rafters more than 2' centers. Any mroe than that and its truss territory....

As to the beam and what will or wont work....can help without more info. And even then, our ability to help is limited. I'd try to find out who built the building, and it may be worthwhile to have an engineer take a look. Cause right now...I'm not liking the rafter situation from what I can see.

Yeah those pics are hard to tell just what he has going on there but just looking at then it seems to me he would be better off going with a truss system rather than those large beams. That way he would not have to worry about the post in the middle or the added load of the roof on his trolley beam. He could also have the truss beefed up to help carry a little of the load on the H beam he wants to add.

I went through the same thing when I built my barn and I remember spending two or three months arguing with some folks on another site about why what I wanted to do would not work. Heck, I even had one guy follow me around to other sites telling everybody I was crazy and not to give me any help for fear I would kill myself and most of the neighborhood. I finally gave up on the internet search and built the dang thing and it’s been up for two years and last year the hurricane knocked over a giant oak tree and sent it through the barn and on to the tower and it never budged, so much for it falling down under its own weight.
Having said that putting something like this up needs to be done right and you need to make it strong enough to carry its weight and the load that it may be asked to carry without coming down on your head. I don’t think the beam he first mentioned would be large enough to do it on its own, just to carry the roof load, not to mention any added load like the front end of a car or truck someone may decide to try and lift someday.
He would also need to put in place some pretty decent footers for the upright beam supports before he pours any concrete. I built mine with 4 uprights sitting on footings that were 3’ deep and 30” square with rebar and concrete poured to finish grade. The uprights and cross members were built out of W10X20 I beam and the cross member at the big door was doubled. The 30’ section of beam that spanned the center of the building was a W10X39. I had to weld a 20 and a 10’ section together to get my 30’ span and then I welded two 15’ sections of S 5X10 together and then welded this to the bottom of the large beam for the trolley to run on. So far it hasn’t fell down and killed anyone but I haven’t tried to lift any 10,000lb caddy’s yet though.
Not knowing what kind of experience the OP has it would be hard to say just what he may or may not want/should fool with, with this kind of job. It is after all a dangerous job to begin with messing with 1000+ lb beams on the ground let alone hoisting them 14’ into the air in a way that is safe to use by him and others.