Hey, I'm building a 10x12 shed. 10 wide, 12 deep. I want to do a barn type roof, kind of like the one here: http://bp1.blogger.com/_b94N237ubqI/...orage+shed.jpg

Edit: I just found out those kind of trusses are called gambrel?

But I don't know how to calculate the angles. Does anyone know of a good site that can teach me how to calculate the angles? Or does anyone know them off the top of their heads?

So the trusses would be 10 feet wide, no over hang. Don't really care on the pitch, just average I guess. I know nothing about pitch either, so any pointers to a site that would help me understand would be great.

Thanks.

 

I wanted to just edit the first post, but can't for some reason. I also was wondering how far apart to space the trusses. For instance, if I'm framing 16" on center for the walls, I was assuming doing the same thing with the trusses. However, I can't place the trusses on the same spots as the wall studs, as there are already nails in place. So do I space them differently, or just adjacent to the wall studs?

Thanks.

 

Here are some photos that might help.



You would use 2 top plates. The studs nail to the first plate then the trusses toe-nail to the 2nd plate. Then you can place the trusses right over the studs.

 

Very helpful information. Thanks a bunch. In looking at some of the sheds at Home Depot, the trusses are space about 2 feet apart, instead of 16 inches. Is this just cutting corners? Would it be safer to just do them 16 inches? 2 feet would save me from building a couple of trusses.

Also, another question, while we're on the topic. In designing my plans, I had just planned on framing 8 foot walls, cause that's how regular framing is done, being easier since 2x4's come in that length, it's convenient. But then I realized with the roof I'm putting on this sucker, that's going to be a tall freaking shed. Over 12 feet tall. Is that too tall? Should I scale the walls down a bit, say to 6'6" or something? Or is it ok to make it that tall? (I must admit, I like the idea of the extra headroom. I am making a loft.

 

Putting the trusses on 2' centers is fine. Your roof sheathing (either 7/16" OSB or 1/2" plywood is rated to span that. The OSB even has lines at both 16" and 24" O.C. that serve as nailing guides.

 

Awesome, thanks!

 

you can put them on 2' centers but you won't be happy with the roof a couple of years from now. you will notice a bow between rafters, especially with thinner decking. up to you.

i would make the walls shorter(depending on what the use of the building is). if you need to stand at the wall, then the wall may need to be at least 6'. i would prefer to make it pleasing to the eye and shorten the walls. with the first part of the roof at a 60 deg. angle, the standing room will be adequate within a couple of feet. i make my studs 4'. with the plates it comes to about 4'41/2". whatever make you(and your wife)happy!

 

If you do go 24 inch on center with the trusses why not go 24 inch with the wall studs also? Add 2x4's between the truss ceiling ties where you plan to have the loft unless you do not plan on anything heavier than a few boxes of Christmas decorations up there. Also 3/4 inch decking in loft.
I realize the rating says 1/2 ply or 7/16 osb will span 24 inch, personally, myself I use 3/4 decking on 24 inch spaced roofs and 1/2 ply on 16 inch. Just the way I am. So if I built this shed on 24 inch centers on walls and roof I would use 3/4 deck on the roof and at least 5/8 sheating on the walls. Cost wise I am not sure which would be better. Just my way.

 

90% of the houses on the left coast are built with trusses 24" O.C., with 7/16" OSB sheathing on top of it, and I haven't seen any noticable bow between the rafters, UNLESS several layers of roofing have been added to it. If you are concerned about, use 5/8" sheathing.

As far as the trusses, I would look around and find a lumber yard or truss company and HAVE THEM BUILT. You can design a loft into the trusses if you so desire -- they can do that. It's faster, more accurate, and stronger than what you will build yourself, and cheaper, unless you place "O" value on your time.

 

Well, I do place value on my time, however, most places around here charge over $30 for a small simple truss. I've priced it out, and I can build them for under $5 a piece. (If I'm using scrap OSB for the connectors or whatever you call them.) I think that's a savings I'm willing to spend my time on. I don't think it will be that hard. The hard part was just figuring out what angles to use. Once I know that, it's just a matter of cutting them and putting them together.

I know, you're saying, if you can build them for $5 a piece, why are you worried about saving 2 trusses by spacing them farther apart? Well, I'm thinking I'm going for quality, so I'm thinking I am going to go 16" and pay a little extra. But now I still can't decide on the best angles to build them at. The example above has 30 degrees for the top, and 60 degrees for the bottoms one, but I found a plan with some different angles. So I guess I just can't decide. Thanks again for some good replies.

 

paqman,

$5 a truss might be a little optimistic, but you can probably do them for less than $15 each.

Find a large flat area and build a jig so that you get all of the chords aligned, so all of the trusses are the same. Nothing wrong with building one or two extra trusses and setting them at 16" O.C.

OSB or plywood for the gussets is the way to go if you build them yourself. That's how I did mine. I also put a loft in that shed and lined it with 5/8" plywood.

 

Great, thanks. What do you mean by build myself a jig?

 

The trusses have to be identical. The easiest way to achieve that is to fabricate a jig so that each part of the truss lays in exactly the same spot. You'll be cutting every part of every truss with at least one angle on it. Some of those angles can be done with a chop saw (power miter), but a lot are greater than 45 degrees. Those will have to be done with a Skilsaw.

It's challenge, and you have to think the whole process through thoroughly before you start cutting.

 

Well, I understand the criticality of planning it all out before cutting, and making sure the measurements are exact, and that they're all the same, but just wasn't sure what you meant by a jig. Like some sort of template or something?

 

I looked for pictures of a truss jig but came up blank. So here are my thousand words.
A jig is made by taking plywood and strapping it together until you have enough space to lay your 1st complete truss on it. Sometimes people use the floor of the building instead. Lay the truss on the plywood and take short pieces of 2x4 and screw them on each side of the truss to hold it in place. Not attatched to the truss just beside it. Be sure you place one at the bottom on both sides so the truss cannot slip down. Do several places like this to ensure that when you remove the 1st truss and begin putting the pieces for the second truss in the slots they align perfectly. After all 4 pieces of truss are in the slots and butted together it will be a simple matter to install the gussetts at the joints without them coming apart. Then remove the 2nd truss and install the gussetts on the other side. Then place the parts to the 3rd truss in the jig and continue until done. The jig insures every truss is exactly the same.
If you have level ground space large enough you could drive stakes around the truss instead of using the plywood and 2x4's.
The whole idea is to hold it in place while you install the gussetts so every truss is the same.
Boy a picture would have been a lot easier.
Hope you understand now what the jig is.

 

Well, for working without a photo, you did a pretty good job. Thanks for explaining. I think I get it. That will make it alot easier and faster to make quality trusses.

 

This is a crappy picture, but I think this is what you were getting at?

 

Build the first truss. Leave it resting on a flat surface such as a driveway or garage floor and build the second truss on top of the first, using the first one as a pattern. Remove the second truss and lay it aside. Repeat the process until you have the required number of trusses.

 

yes. I've seen some of the houses on the west coast and elsewhere with 24" O.C. trusses. I have worked and reworked some of them here in TN.. That is why I say I wouldn't build a doghouse on 24OC. If you don't have time/money to do it right, when will there be time/money to do it over. The majority of complaints/problems I see on this site is where someone/somewhere cut some corners!!

 

This isn't really about cutting corners. Really, the difference in price isn't that much. I'm going to do it 16" on center. That was more of a curiosity. I'm really more interested in finding out how to calculate the pitch and angles of the trusses.

 

If I'm building my trusses to exact width of my shed (with no overhang), is there a way I can implement a simple little overhang with just the shingles? Let's call it more of a drip edge. Or is there a better way to implement an overhang.

I just wanted to avoid having cross beams at the bottom of the trusses (for higher storage access) so I'm not sure how to build an overhang into the trusses. FYI - The back half of the shed will have 2x6's going across the trusses, as I'll be building a loft, and they will be going across the top supporting it.

By the way, if anyone is interested, here is a pdf of the angles and dimensions I've got planned for my trusses.

 

You can always use a double starter strip on the shingles to create a drip-edge of sorts. Or install a metal angle at the start...maybe a drop ceiling wall angle. Depends on how much edge you want.
Nice pdf by the way.

 

Thanks! By double starter strip, you mean, just two shingles on top of eachother on the edges? Sorry, not very technical. Also, what's a drop ceiling wall angle? I'm assuming just a strip of metal placed on the edge or something?