I thought it might be an apropriate time for Boss to line me out. This might prove interresting, might should sell tickets to this one .
Ok Boss ,
Here goes. Ive made trusses for small houses for a long time [Mostly rentals, and very small houses] I have read some of your information and realize compared to you, I dont know a lot about it . All I know is to stay with principals Ive learned over the years. But you break it down lots more. Heres the question ;
Should builders build there own trusses , and if they did , what book would we need , or information should we use
Thanks in advance [because he will take an honest stab at this , yall wait and see]
Tim Mooney
Replies
Boss- where are you?
Half of good living is staying out of bad situations.
So Rez, you think this will be good ?
Tim Mooney
Tim,
Why pay more for an inferior product that has large liability when you can just order trusses?
KK
http://curve.phpwebhosting.com/~luka/ubbthreads/categories.php?Cat=
Ok, How do you know what Im doing is inferior ? Im doing it because of two things , but mostly one. One is green building [lesser] and the other is money .
That answered, we might just learn something out of this . Ive been here a long time , and no one has asked him that I know of. WE could still be percieving the world is flat. [pun intended of course].
Now I will ask you questions. Are your rafters inferior because they are your product ? Do you believe that because trusses come from a plant , are special in some way ? Dont you believe that some of the stuff you are told is selling ???
I have drawings of lots of trusses. I blue print every set I see. Difference is my fasteners are 5/8 plywood. Thats why I asked you how you thought they would be inferior.
There is another issue with me . I grew up with my father on a job. Thats how I was raised. WE did it all! period . all of it . WE are the builders of today .We are letting our trade be a history. Here is a list of things regular carpenters dont do any more ;
Nearly everything !!!!
Tim Mooney
ya- he's either out of the house or thinking real hard.Half of good living is staying out of bad situations.
Tim -
Sorry I didn't reply Sunday - Was out working until 9pm, and didn't feel like turning the computer on when I got home.
Since you asked, I'll assume you want to know the truth about what I think. Actually, I've answered this question a few times before. I've wondered if I wrote something up if Joe F. would be willing to post it on his web page so I could refer people to it.
Basically, I would say that no one should build their own trusses for several reasons. First is engineering. Where will you get it from? There aren't any books out there about making your own trusses. (As far as I know) Anyone who wrote one would be assuming an enormous amount of liability, so I don't look for a series to be published. How will you decide what lumber size, species, and grade to use? How big will the plywood gussets be? How many nails in each joint, and what size?
Getting lumber can be a problem depending on where you're at. Around here, lumberyards don't stock grades of lumber that are adequate for trusses. (Unless you get 2X8 or bigger)
Second is liability. As I understand it, there is no statute of limitations on liability. so you would be responsible for the design of the trusses for as long as they existed.
You also need to throw quality control in there. How will you jig the things to keep them consistent from one truss to the next? You can spend a heck of a lot of time building a jig to try to do this.
Keep in mind that a truss (Like a chain) is only as strong as it's weakest link. Screw up oine thing and the whole truss is basically worthless.
Having said that, I would also say that I've never seen a homemade truss that's even close to the quality you would get out of the worst truss plant I've worked at. I've seen trusses put together with 1/4" luan and staples from a stapler. (The kind you would staple felt down with)
I know of a set where they copied the design from an existing truss. They matched lumber sizes and the web pattern perfectly. And they matched the size of the plywood gussets to the size of the metal plates on the existing truss. The bottom chord splice was held together with a 3X6 piece of plywood with a couple of roofing nails in it. And they used SPF Std & btr. lumber, which has very little structural value. I'd like to go by someday and see if they're still standing.
For some reason this seems to be a touchy subject with some guys. Almost every time this comes up I get flamed by someone who thinks they know better. I once caught hell for telling a guy (On a farming message board) that he shouldn't build his own 60' clear span 8' O.C. pole barn trusses. He thought he knew more about engineering than anyone else and didn't want to hear otherwise.
On the other hand - If you're building for your own house or garage or whatever, why not? Slap something up and go with it. If it gets overloaded with snow and collapses, your insurance will cover it. And everybody else will pick up the cost through higher insurance premiums.
So is that what you wanted to know?
Stop repeat offenders. Don't re-elect them
You must have been posting yours when I was posting mine.
I know that the same plywood size cleat is not the same. I know that spruce is inferior except in the web. I know I dont know enough on this subject . [Thats why Im asking] I intend no insult to you or the truss industry . My family and I have been doing it since 1965. This is not a new thing Im working on here. I can tell your biassed on the subject , and that is perfectly fine. Im the same way where my knowledge is greater. What I do think is funny ; I have most of the rafter books that has been printed. Never in any book that I have explains making trusses. This is amazing . I can find a book on any thing else I want . [that Im aware of anyway ] Ive even got a doctor book !!!!! lol. [pun intended here ]
So lets go at this from another angle . What do I need to do to be a truss plant ? Because information is not available , I think this is a gimic business, until you tell me differently.
Thanks Boss.
Tim Mooney
"I have most of the rafter books that has been printed. Never in any book that I have explains making trusses. This is amazing."
I don't find it amazing at all. Did you catch what I said about engineering and the statute of limitations? If I wrote a book about how to design and build trusses, (and people actually bought it) I woud be asuming liability for an enormous amount of strutures for maybe the next century or more. No way anyone wants to do that for what little amount you could make off book sales.
Another thing to consider is that such a book would be outdated in a few years. They're always tinkering with lumber values, design methodology, etc. So the book wouldn't be effective for very long.
"What do I need to do to be a truss plant ? Because information is not available , I think this is a gimic business, until you tell me differently."
Not sure what you mean by "gimic business". Truss plants - Like most businesses - are turning more towards automation and technology to stay competitive. A basic truss assembly table starts at about $100,000 and only go up from there. Component saws start at $100,000 and go up to $250,000. Then you also need lumber inventory, forklifts, trucks, truss stackers, and staff. Takes a lot of bucks to get off the ground.
Or are you asking how you get started with designing the trusses? Most places that start a plant hire someone away from another company. Don't know that I've ever seen an exception to that. New people are typically sent to the plate/software/engineering company to get training in truss design. Takes about a year to get them to the point where they're productive and can work indepentently.
Truss design is like building a house, in a way. There's no one single thing that's all that difficult. But there are a million things to remember, and you have to remember every one on every job.
I guess I AM biased - but for good reason. As I said in my other post, I've never seen a decent set of home made trusses. And there are a lot of pitfalls - Things people don't think about when they build their own trusses. I don't suggest buying factory built trusses for selfish reasons, but practical ones. I'm not feeding you (Or anyone else) some rehearsed line of B.S. that I've been fed - This is based on my experience.
Keep working, millions on welfare depend on you.
For what it's worth; back in the 60's and 70's Oregon State University Extension Service (and probably other state extension offices around the country) offered a handbook that had a variety of truss plans, all engineered, with specific gusset sizes, nailing schedules, and lumber specs and dimensions for each component. They were, of course, intended for barns, loafing sheds (I could use one of those), or other agricultural outbuildings. I've noted over the years that many of the county fair sites employed those trusses in in the construction of many of the exhibition buildings and they're still going strong.
That being said, in that era, the lumber (doug fir) was tighter grained and the plywood was of a more consistent quality.
My Dad and I built a small barn using those trusses and I distinctly remember his observation that by the time we'd bought our small quantity of lumber, a zillion nails and the plywood, we really didn't save much over manufactured trusses simply because they (the truss plants) could buy the lumber and plywood by the railcar load.
I don't believe that truss handbook is available anymore due to the liability reasons cited by BossHog.
You indirectly brought up something that I forgot to mention earlier.
I've often gotten the arguement that "My trusses have stood for X years and they haven't fallen yet". That may be true, but it's not a guarantee of future performance.
I look at it like this: Take off down the highway in your car. Close your eyes for 10 seconds and see if you hit anything.
Since you didn't hit anything in that 10 seconds, does that mean you won't in 15 seconds, or 20?
That 100 year snowfall may not have happened for a long time. Might be 50 years off, or could be next winter.
Another thing to consider is construction loads. I designed trusses for a job last year that due to a collapse. The homeowner hired someone to come in and add a second layer of shingles to their house. The roofer was in the process of stocking all the shingles along the ridge when the roof collapsed.
PETA: People Eating Tasty Animals.
> A basic truss assembly table starts at about $100,000 and only go up from there. Component saws start at $100,000 and go up to $250,000. Then you also need lumber inventory, forklifts, trucks, truss stackers, and staff.
Boss, could you post some pictures?
Thanks --
-- J.S.
There is another issue with me . I grew up with my father on a job. Thats how I was raised. WE did it all! period . all of it .
Really? Planted them lil saplings? Felled the trees? Milled 'em? Graded 'em? Calculated the span tables? Made the nails? Filled the saw blades from a blank? Etc.
As a home inspector, I see site built trusses from time time time, mainly cheap mini-ranches with a host of problems - sometimes in the trusses, although they tend to appear overbuilt.
FWIW, if I saw a new house with site-built trusses I'd tell my client to be very careful: e.g., demand engineering plans for the the trusses, which would wipe out any cost savings, if not the sale. I'd also go on high alert, figuring anyone who did something so unconvential probably has donme some other curious things which I ought to pay close attention to.
Bob , where are you from ? Where do you hang your hat?
I live in rural Arkansas . Yes we did log the timber and take it to mill. But I have a feeling you live in a much better place
Tim Mooney
Really? Planted them lil saplings? Felled the trees? Milled 'em? Graded 'em? Calculated the span tables? Made the nails? Filled the saw blades from a blank? Etc.Everything except file the saw blade. Have made small buildings from trees I planted myself also.
What's this 'grading' stuff though, that mean lookin' at it and figuring its solid enough? Only once made own steel from stuff dug out of the ground, only once made a small bullseye of glass. Probably no one alive could make a microchip themselves with only a shovel and pick to start with though........
"Boss, could you post some pictures? "
Pictures of the wood ???
O.K., just kidding. Here are some different component saws:
http://www.alpineequip.com/AutomillRS.htm
http://www.alpineequip.com/autoweb.htm
http://www.alpineequip.com/tm620g.htm
http://www.alpineequip.com/tm4-14.htm
for truss assembly, here's an older style hydraulic press:
http://www.alpineequip.com/lm5000.htm
Here's a relatively poor picture of a more modern roller press;
http://www.alpineequip.com/rolamast.htm
This is an automated jigging system:
http://www.alpineequip.com/autosetc.htm
And a finishing press:
http://www.alpineequip.com/rollerpr.htm
How about a truss stacker, for after they're built?
http://www.alpineequip.com/autostkr.htm
Here's a floor truss roller press:
http://www.alpineequip.com/FloorMaster.htm
How about some wall panel equipment?
Here's a framing table:
http://www.alpineequip.com/FramingStation.htm
And a sheathing table:
http://www.alpineequip.com/SheetingStation.htm
And a stapling bridge:
http://www.alpineequip.com/NailingStation.htm
Bumpersticker: Do you think you'd drive any better with that phone up your ####?
Boss, I want to thank you for your time. An exellent job done again. You are the stand up guy I adverstised you to be. You are always great under fire , and I commend you.
On one more note that you need not answer. Our truss plants here in rural Arkansas look more like an implement shed . I have seen none of the fine things you mention . So now Im wondering if they should cut a truss for any one. Im sure you would call their facility a joke . You dont think I should make my own , and after reading , I dont they should either. Now its got me wondering .
Thanks again ,
Tim Mooney
Boss -- Thanks for the links. I think the pictures really make your point that trusses can be made more efficiently by a fully equipped plant.
-- J.S.
I also agree .[ If we just had one]. He does this every time he is called upon . Ive told him already we are lucky to have him aboard.
Tim Mooney
Boss
I enjoyed your input on the subject, I once considered doing the same thing that Tim wants to do but I ran the numbers and all engineering aside I didn't feel that there was that much if any, savings. I felt that I could probably go down to the local fast food joint and work a couple of evenings and have the difference and no worry that I was screwing something up. Just my opinion and nothing against Tim for wanting to do it.
Doug
Thanks for the kind words, guys. I've dealt with all these issues we've covered many times over many years. Once you get me started on this stuff it's hard to shut me up.................(-:
A couple of other notes regarding specific posts.
Tim Mooney - Your plants in Arkansas might not look great, but may still be O.K. A look inside will tell you a lot more about how they do things and whether or not they do a good job. Kinda like judging a contractor by how his pickup truck looks.
John Sprung - I hope I didn't imply that all truss plants have modern equipment. But like most businesses, they're buying each other out and automating in order to become bigger and more efficient. Automation reduces the need for labor. And truss plants have as hard a time getting and keeping good help just like everyone else.
To give you an idea of what an automated saw can mean - An older component saw had either hand cranks or motors to move the blades around into the correct position. Then a board was run through and checked for the correct length. This process may take up to 10 minutes, and involve 2 people. If the saw is calibrated correctly, you don't need to measure the stuff coming out - It's always correct.
An automated saw can do the same thing in 10 to 30 seconds. Since roof truss profiles are trending towards low quantities of oddball trusses instead of high quantities of simple ones, this is important.
BTW - Didn't know if you realized that the pieces go through the component saws on a conveyor. The boards are stood up on edge and held in place with chains. The blades are stationary, and the boards pass by them. All the cuts are done on a board in a second or 2, and the pieces on the conveyor go through at the rate of one every couple of seconds. They're done on a conveyor so that each piece is consistent. Much more so then if they were cut by hand or on a radial arm saw. Some of these saws have an ink jet printer that marks each board as it comes out, so you know exactly where it goes in what truss.
The modern roller presses are also important. When I started in the business, there was a big hydraulic clamp suspended from an I-beam. You had to drag it around to each joint manually, then stop and press each joint. It worked O.K., but was painfully slow. The newer roller presses simply pass over the entire truss, and press every plate no matter where it is.
Wall panel equipment is also amazing. The last plant I worked at was turning out roughly 1,500 running feet of wall panel per 8 hour shift with 5 guys. And the quality of the panels was superior to most anything I see that's stick built on site.
The tables have light bars to show where each piece goes. There are clamps at 16" O.C. so you don't need to lay out the studs on the plates. And there's a computer monitor suspended from the ceiling so you can see a picture of the wall panel that you're working on. Nailing the studs is done with 2 nail guns mounted on a carriage, so the guy doesn't have to carry them. The stapling bridge I linked to can put staples in an entire stud in a couple of seconds. (I think there's about 15 staple guns mounted on it)
I told you once you got me going on this stuff I wouldn't shut up.................
My kid beat up your honor student.
Thanks for not shutting up.
Tim Mooney
James Ambrose has out a truss book.
"Design of Building Trusses"
http://www.amazon.com/exec/obidos/ASIN/0471558427/qid=1026752408/sr=1-17/ref=sr_1_17/002-6213366-0467257
He also has some simplied building design and simplied engineering series. I looked at one (forgot which one, the computer crashed), but the table of contents also showed some truss design information.
Also it appears that barnplans.com designs comes with the truss designed for their buildings.
http://www.barnplans.com/trusses.html
Bill thanks for posting the information , I will look at all of it and buy the book .
Tim Mooney
Boss,
View Image
matched the size of the plywood gussets to the size of the metal plates on the existing trussLOL at that part --