Hello, I am in the planning stages of building a 50'Wx 60'L clear span truss hybrid shop. I have recieved qoutes from WebSteel and Perka, and have liked dealing with Perka the best. The Perka sales person has suggested the 4000 Series truss, which is two frames welded together, but she said that the engineers will determine what size Angle would be used. Anyone have any idea what size angle would be used??? If I can save enough I would just build my own, current price is $13K for 6 Trusses. If you cant answer this specific question, what kind of material is used for your clear span trusses. Thanks.
Perka Truss Angle iron size
- Thread starter Midge907
- Start date
You want to build your own 50 foot clear span steel truss and you are asking the interwebs what size steel to use.
PAToyota
Well-known member
I'll do the engineering calculations and give you fabrication drawings for $9000...
Wow, I was thinking of charging him only $3700. I defer to your better estimate.
PAToyota
Well-known member
Well, since he didn't list a location, I was throwing in costs for out of state sealing of the drawings.
OUCH!!! Burned on my first posting. I am in Fairbanks, Alaska, so the shipping of the plans will be spendy, lol. I am a Journeyman-Foreman welder/fabricator by trade, and am very capable of building angle iron trusses, even though sometimes it easier and worth just purchasing such things. I dont need to have a engineer stamped plan in order to build in my location, so that is not of consideration. I was just wondering what approximate size angle that others are using for doing a double frame with a 40lb live load. Not a joke, but a serious question. I could go to the engineering firm next to my shop, but all we seem to ever do up here is I-beam construction, so I doubt they would be able to help. I have mechanical engineers at my disposal, but I know they wont be any help for clear span trusses, with a wood shell. So take it easy on me guys, lol. Im sensitive.
LutzTD
Well-known member
If everyone around is doing ibeams I would bet thats the cheaper construction. considering the wind and snow loads in Alaska Id be a little hesitant to use angle trusses, and maybe even a little less willing to be under some fabbed from scratch
Justanoldguy
Well-known member
LutzTD
Well-known member
Every truss ever made is fabbed from scratch.
true, but a truss maker will have experience and jigs.......
Well I guess I asked this question in the wrong spot, and wrong context, with the wrong crowd. I will speak with one of our mechanical engineers and see what he suggest. Not a big fan of dealing with engineers just so I can get a "stamp" of approval, on something that has already been manufactured all around the country.
And I could and would build a Jig. Choosing the correct material size without going overboard is my main concern. I am still planning on purchasing, but I am just looking at my options.
$13k for trusses plus shipping or Price of angle and my labor is something I will have to work out.
MBfreak
MEMBER EMERITUS
Hi Midge.
I have built a carport where the structure is made from I beams. Due to planning restrictions I had to make a flat roof. Span is 24 feet. Module between beams is 2 feet. Calculated for 1 meter ( 40 inches) of snow load, which is the norm here at 60 degrees North.
Calcs gave next biggest beam as 16 cm I beam. The max flex was 2 mm at a simulated snow load of 1 meter when the inspection geeks came and "verified" my calcs. Calcs were based on a 45 year old textbook from college.
I hade no isues with the fire code since it is an open, outdoor structure. Had it been an enclosed building steel fram would not be an alternative, due to prohibitive cost of fireproofing the steel. I would then have gone with laminated glued beams, with no issues for fire code.
The calculations for the trusses are easy and I am sure that there are standard programs that plug into excel that will give you accurate results.
Good luck with your calcs and build.
Ola
I have built a carport where the structure is made from I beams. Due to planning restrictions I had to make a flat roof. Span is 24 feet. Module between beams is 2 feet. Calculated for 1 meter ( 40 inches) of snow load, which is the norm here at 60 degrees North.
Calcs gave next biggest beam as 16 cm I beam. The max flex was 2 mm at a simulated snow load of 1 meter when the inspection geeks came and "verified" my calcs. Calcs were based on a 45 year old textbook from college.
I hade no isues with the fire code since it is an open, outdoor structure. Had it been an enclosed building steel fram would not be an alternative, due to prohibitive cost of fireproofing the steel. I would then have gone with laminated glued beams, with no issues for fire code.
The calculations for the trusses are easy and I am sure that there are standard programs that plug into excel that will give you accurate results.
Good luck with your calcs and build.
Ola
Nothing simple about 50+ tons over your head subjected to wind, snow, and earthquake loading. How do you expect to insure this cavern?
LutzTD
Well-known member
your choice. I think there is a lot to know about such a large structure, but if your life and peace of mind are only worth the 2-3K you would spend on a PE, thats your decision........ maybe my opinion, but you asked for opinions, knowing how to weld is only a fraction of the requirements to get a safe building with such a large span.
After building I would have it appraised.
I'll be talking to a engineer in about two hours to get some more opinions, and they have plenty
Good choice. I predict you will be glad you did. I actually hope this works out for you and that you can use your expertise in the build. An appraisal after the fact does you no good insurance-wise if the agent considers your build too big a risk. You may not even be able to obtain insurance. Or your premiums are so high you could have saved money with engineered trusses. A good appraiser will want to see the stamp or specs on the build. You would eventually have to disclose to a prospective buyer the nature of the roofing job and that could cost you plenty.
Do it right and save money in the long run. No building rules.
Justanoldguy
Well-known member
I can see why a lot of guys don't bother asking questions on here.
Rarely do they ever get a clear answer to anything.
Usually things end up in a ***** fest ...
Rarely do they ever get a clear answer to anything.
Usually things end up in a ***** fest ...
PAToyota
Well-known member
Wasn't trying to be a smartass, but from your initial post we had no way of knowing if you just "thought" you'd be able to weld this up with the MIG welder you just picked up at Harbor Freight...
Yes, angle iron trusses are built and used everywhere. But I can guarantee you that the ones designed for a building in my area aren't going to work for your area... I wouldn't even know what a "general" snow load would be for your area (yes, I could certainly look it up). But what would be a straightforward design if someone local asked me the same question would first entail a bit of research to do the same for your area.
Yes, angle iron trusses are built and used everywhere. But I can guarantee you that the ones designed for a building in my area aren't going to work for your area... I wouldn't even know what a "general" snow load would be for your area (yes, I could certainly look it up). But what would be a straightforward design if someone local asked me the same question would first entail a bit of research to do the same for your area.
willymakeit
Well-known member
To the OP ,I will bet that there is a web site where the calcs. will be.
There are all sorts of span charts for wood framing members and there is no reason not to have some for steel. Look them up ,take the calcs to your engineer and the truss drawings and he can make the needed changes if any.
All of their info is in a data base and is what is used. You will have done the legwork and proably saved yourself money. Ive had engineers stamp items for me in the past when doing mods. The info is out there.
Hope this helps. I build items myself all the time and commend you for wanting to do yours.
There are all sorts of span charts for wood framing members and there is no reason not to have some for steel. Look them up ,take the calcs to your engineer and the truss drawings and he can make the needed changes if any.
All of their info is in a data base and is what is used. You will have done the legwork and proably saved yourself money. Ive had engineers stamp items for me in the past when doing mods. The info is out there.
Hope this helps. I build items myself all the time and commend you for wanting to do yours.
I can understand your concern when it comes to this. We generally build to 40lb sf live load, even though we havent seen anything close to that since 92. I would bet that you get more snow in Erie, PA at one time, then we get all year on most years. Fairbanks also does not have much for wind, and the building will have low walls (12' outside). No tornadoes, or hurricanes either
And no I didnt just buy a mig welder from harbor freight, and think that I could build these out in my yard, lol. My mechanical engineer is trying to get me in touch with two structual engineers to see if they have any experience with clear span trusses, at least that way I can bounce ideas with him.Thanks, and I am trying to find more info. However there is only so much time in the day, so I am bouncing all over with different stuff. That is why I was just trying to see what material others had there trusses made out of, so that I could do so real quick approx. angle sizes, just so I can see "about" how much angle I would have to purchase and cost. My "guess" at the moment would be 3"x3"x 1/4" angle, but not enough info to go on. I did have to order 3400Lf of 1.5"x 1.5"x 1/8" angle today for a totally un-related project. Not looking forward to cutting it all up in the iron worker to tell you the truth, all of it gets cut to between 18" and 22".