truss equations

[Ron Journeau]

Finally got the go ahead from the city and swmbo to start the planning stages for my little shop/storage shed. Initial building size is 14 x 28, hopefully with a 6/12 slope on the roof. I have been searching for the math needed to calculate the height and length of my trusses, but am not understanding the little I have come up with. If I am understanding this correctly, I should have about a 1 ft. overhang on each side, making my truss length about 16 ft....right? So where do I go to crunch out the height of the peak? In case you haven't noticed, math is not my strong suit.....but then again, neither is woodworking!

[Don Baer]

Get a hold of Rennie, that's how he made his living.

[Jim DeLaney]

For a 6/12 slope, with a 16 foot overall width, you'd want the rise to be four feet (48") over the eight foot run (half the truss width), and that'd make the rafters about 8'9½" long.

[Chuck Thoits]

If the bottom cord of your truss is 16 feet. Half of that is 8 feet. you have a 6/12 pitch which means for every 12" in run there is a 6" rise. So 8 feet times 6" = 48" or 4 feet. Now if you have the math skills Jim has you know how to get the third leg of the equation. In theory the math tells you how long the rafter should be. Me I just measure it cause 9 out of 10 times the theory and the real world don't mix.

[Ron Journeau]

thanks guys, seeing it written down on paper in front of me made me realize how easy it really was, couldn't see the forest for the trees. Thanks again

ron

[Jim DeLaney]

...I just measure it cause 9 out of 10 times the theory and the real world don't mix.

See the tagline on my signature? It's true more times than not!

[Chuck Thoits]

See the tagline on my signature? It's true more times than not!

That's what I said Jim

[Bill Arnold]

When I built the addition to my shop building, a friend suggested contacting a local truss company for a quote. They do trusses for any size structure all the way up to major apartment complexes. I was pleasantly surprised when the quote for professionally engineered trusses was for no more than the materials would have cost me, to say nothing of the time savings. It might be worth checking into in your location.

[Dan Noren]

just for the fun of it, i looked for an online truss calculator. i punched in your numbers, and this is what it came up with.

RAFTER LENGTH CALCULATOR

Overhang:1' 0" 0
Span: 14' 0" 0

Your results are as follows:
Units in Feet (Span)= 14
Units in Feet (Overhang)= 1

Slope = 8' 11" 5/16"

[Chuck Thoits]

Dan your math don't agree with Jim"s math
See there ya have it my way of just plan measuring bets math every time