24' trusses

[ironman2424]

im fixing to build a 24x30 shop and need a little help on the trusses. i'll be doing all the work myself (pad included) with help as needed. my question is: on a 4/12 pitch how long do the 2 top cross peices need to be to come out to a true 4/12 across 24'. i'm guessing 14' each side but im not sure. also the trusses are not going past the walls which will be alittle over 10' high. im planning on setting the trusses on 3' centers and using 1x4's across the trusses to skin out the roof with galvalume. i will be putting 2x4's between each truss for bracing to keep them from shifting side to side. i'm in south arkansas and we rarely see snow and ice so weight load is not a big issue.
are and all advice is appreciated. my reason for 3' on center is so i can screw the metal through both the 1x4's and each truss where the metal will overlap.
does this sound right to ya'll? thanks ahead of time.

 

[Kevin54]

With no overhang at all and coming out right at an even 12' across the bottom chord, each side ofyour top 2"x4" calculates out to 152.96" or 12.75'. That is from the longest point on each end as the ends will be cut at 18.435 degrees. So if cut correctly a little less than 13'. And you'll have to pick up 14' lengths. Are you planning on building the trusses yourself? If so, I would save some time and just buy them. By the time you get the lumber, do all the cutting, cut the webs in between.........Most lumber yards stock the 4/12 x 24' trusses on hand for around $30-40 apiece. Just my $.02 on it.

 

[boiler7904]

Like Kevin, I'd order the trusses from a lumber yard - preferably one with a truck crane to set them on the walls. The cost to do it yourself is going to be close to what they'll charge before you figure in the value of your time.

One thing to consider is that a metal panel that's advertised as 36" coverage may have attachment clips that are off of that dimension by a fraction of an inch. I doubt that you'll be screwing each panel into the top chord of a truss. Trusses at 24' on center and plywood or OSB sheathing might be a better route to go - especially if you plan to insulate and heat the building.

Something else to consider is the engineering that goes into designing the trusses. Most municipalities won't allow homebuilt trusses unless you have a set of signed and stamped engineering drawings from a local structural engineer or architect. That in itself can be several hundred dollars. Again eating into your perceived savings of building them yourself.

 

[CraigFL]

...Something else to consider is the engineering that goes into designing the trusses. Most municipalities won't allow homebuilt trusses unless you have a set of signed and stamped engineering drawings from a local structural engineer or architect. That in itself can be several hundred dollars. Again eating into your perceived savings of building them yourself.

The thing I'd worry about most is the actual truss construction. Companies that do this use special "nail" plates that are pressed into the junctions of the wood chords. This is not easy to do by hand to give it the proper strength.

 

[boiler7904]

There are a couple of ways to design the connections between the chord and web members of the truss depending on the loading conditions and the materials that are available. Not something that I would encourage a DIY to tackle though as there would be very specific fastener schedules and fastener placement requirements. The cost of some of the specialty hardware also drives the cost up making pre-fab trusses that much more attractive.

Another thing that I didn't mention in my first post is that if you are able to build your own trusses, you need take the time to build a jig that allows all of the trusses to be identical. If the trusses end up being different lengths or the peak is off center, the metal roofing, ridge cap, and fascia / gutters are going to be anything but straight.

 

[1atom12]

Ive built many of my own trusses, some up to 32 feet wide, plywood gusset plates glued and screwed or nailed together, after twenty years I haven't had one fail, thats with alot of snow, ice and wind. Do build a jig make sure your cuts are clean and all connection points are tight. Good Luck. I have also bought many prefabbed trusses and I believe mine will hold up better. Just my .02cents.

 

[ironman2424]

i was planning on building a jig after i pour my slab. using the slab to build my jig on should be about as flat a surface as one could get. im out in the country. building codes don't apply here for outbuildings as we call them down south. i am going to use plywood gusset plates along with glue and nails. i priced pre built trusses from $95 to $110 apeice locally. that's just to high for a shop building. 16' untreated #2 2x4's are around $5 here which puts each truss at about $40 max; if i do it myself.
i can have a reputable construction company build me a 24'x30' for alittle less than $9000 w/4" pad but i see no reason why i couldn't do it for less than $6k. plus my wife has agreed to let me have a new high dollar stainless steel grill if i do the buiding myself.
i'm very able to do trusses. i just wasn't sure how long the top chords needed to be. the only thing i am going to hire out for sure is the pouring/finishing of the slab. that's going to cost me $300 plus 11 yards of concrete. my dad is going to help me build the forms this weekend. it may take me till the end of may to get it all done but time is money to me
and i don't mind the time. i work 6 straight and have 4 days off in a row so that's going to be a big help with building it myself.
thank yall for all your input and help on this.

 

[Kevin54]

i priced pre built trusses from $95 to $110 apeice locally. that's just to high for a shop building. 16' untreated #2 2x4's are around $5 here which puts each truss at about $40 max; if i do it myself.

Those prices are way too high for a standard 24' truss. I think all of the lumberyards, including Home Depots and Lowes carry the 24' as standard stock. I was a little low on the $35-40 as it has been a couple of years since I bought any, but I remember seeing them at Carter Lumber yards for around $35 on sale which was last year I believe. But as everything prices have went up some. I did a search on truss prices and in Michigan and Indiana, one particular chain sells 24' for $44 and change http://www.michianabuildingsupplies...chianabuildingsupplies.com/trusspricepage.htm That same company sells a 40' for a higher load /sq.ft. for only $116.00. I'd call around a few places in your area and get some different prices. As I stated. $110 for a standard 24' is way too high. You might even do an online search for truss manufactures in your area or even out of your area as they may deliver past your way. All I know is that for the price and time, I'd buy before building my own. If I were going to build my own, I would change the design somewhat so you could incorporate a floor into the design and then just put rafters up. Then you would have either overhead storage or an overhead mancave.