Pre-fab trusses for shed style shop?

[N80]

Thanks guys. Tons of great info here. Lots of things to consider.

As far as snow, not an issue. We get snow accumulation every 4 or 5 years but rarely more than a few inches. Sitting on the front porch of the cabin right now and it’s 65, windy and bats are out.

As far as birds in the trusses, I will likely put a ceiling in.

As far as attic storage I’ve already written that off.

As far as steel trusses, my nephew recently built a 40x100 foot barn with metal trusses from a place in Georgia and he says they are already torqued and twisted. Maybe he gave the wrong specs but his experience has put me off of that path until I can do some more research.

Agree about over hang. In my opinion more is better.

A little concerned about the height at the front as someone mentioned.

What is the lowest slope you can use in an area where snow is not an issue?

 

[MasseyFerg231]

I am in the process of planning a shop for down on my property. I have no idea if this will become a reality as it is still early in the planning stage. What I want/need is a 30x40 3 bay shop.

I have had a site prep guy out and he says location is fine and won't need too much earth moving at all.

I will be milling my own lumber. I will be doing most of the work myself. It will be on a concrete slab (concrete contractor). It will be stick built. Probably on a low cinder block knee wall. 5v crimp metal roof. Looking for about 12' of height clearance inside.

When I built my log cabin kit 20 years ago it came with prefab wooden scissor trusses for a single peak roof. They were no problem to install.

However, I would prefer that my shop have a shed roof that slopes to the back (where drainage is best.) I would prefer to have a clear internal space with no posts/columns.

My question is this: Can pre-fab shed type trusses be purchased? Any guesses on cost? Is it feasible to make your own? Any ideas much appreciated.

Are you wanting a single slope roof? If so, you could frame out of i joist or dimensional lumber or a floor type girder truss by building a knee wall on the high side wall.

You would just need to have a girder running perpendicular every so often depending on your spans.

 

[3Ts]

As far as steel trusses, my nephew recently built a 40x100 foot barn with metal trusses from a place in Georgia and he says they are already torqued and twisted. Maybe he gave the wrong specs but his experience has put me off of that path until I can do some more research.

I find that odd. I have a 40' x 95' barn and while it's not exactly a truss, it does have a clear span of 40' with 20' spacing. It uses "I-beam" for both columns and rafters spaced every 20' with purlins in between.

What is the lowest slope you can use in an area where snow is not an issue?

Depends on the roof material. If it's fiberglass shingles, manufacturers say no less than a 3 in 12. If it's steel sheet, I believe you can go as low as 1 in 12, mine is 2 in 12 and I personally wouldn't go any less.

 

[newbury]

As far as snow, not an issue. We get snow accumulation every 4 or 5 years but rarely more than a few inches. Sitting on the front porch of the cabin right now and it’s 65, windy and bats are out.

Are you prepared for it to be destroyed by the changing climate?
I HAD a 40' wide Versatube carport, very sturdy, in northeast Mississippi over 10yrs old. Lasted through several multi-inch snowfalls, one up to 4". But the AVERAGE is only 0.7"/yr linky
Last year we got a snowstorm, followed by an icestorm. Crashed to the ground. As did a lot of structures in the area. There were Gas station canopies down ALL over the area.

 

[N80]

Are you prepared for it to be destroyed by the changing climate?

I'm not planning on ignoring structural concerns. Just probably won't build it to take Buffalo, New York type snow loads. Plus, I'm still in the 'idea' phase here. No hard plans yet.

We have friends in the northern part of the delta. They had a covered pergola type thing in their back yard and the snow collapsed it, probably in the same storm you're talking about.

When I was kid we lived in Clarksdale, just below Memphis. We got snow there regularly.

Where my cabin is, any snow is pretty rare. In the last 30 years I can remember maybe four or five times it has covered the ground there. The last big snow we had there was maybe 5 or 6 years ago and even my 40x20 tractor shed held up fine and it only has a 1:12 slope on it and it was built by someone with so-so skills and virtually no prior experience in that type of construction....although I did look over snow and wind load stuff before I built it. ;-)

 

[N80]

Also, someone mentioned inspections and using my own (ungraded) lumber. I'm not expecting to have to deal with any of that. Typically not a problem in this area with add-on buildings, shops, barns, sheds etc. We did have to have a permit and inspections when we built the cabin of course. The only issue would be if the power company requires a permit or inspection to hook it up to the pole. If that's the case then that's a whole other can or worms and might be a deal breaker.

 

[jthibodeau89]

Here in TN, our local power co-op requires an electrical permit to install a meter. If you daisy chain from house, they could care less. When installing a meter to a structure they require the meter box, 2 8' ground rods driven vertically with 6ga solid copper wire (not stranded), and a distribution panel with at least 3 circuits: an out door light, an indoor light, and an outlet. All installed to code prior to meter connection. The only exception is a well pump meter which is just a weather tight CB box below the meter (no lights). I have one of those, too.

 

[meackerman]

when I build my 30x40 shop I went with premade trusses. The best part was the truss company delivered them and put them up on the roof. We just had to move them to where they went. I also had them design into the trusses, storage space....so some of the members are bigger than if I hadn't had them design in storage space.

 

[N80]

Here in TN, our local power co-op requires an electrical permit to install a meter. If you daisy chain from house, they could care less. When installing a meter to a structure they require the meter box, 2 8' ground rods driven vertically with 6ga solid copper wire (not stranded), and a distribution panel with at least 3 circuits: an out door light, an indoor light, and an outlet. All installed to code prior to meter connection. The only exception is a well pump meter which is just a weather tight CB box below the meter (no lights). I have one of those, too.

I suspect if I have them put in a meter our requirements here would be the same or similar. The county goes by what they call the International Building code. At least they did 20 years ago. It almost derailed the construction of my cabin as they make no provision for things like hunting cabins etc. So unless you knew people then you had to follow the code to the letter. We 'knew' a few people and got some slack here and there thank goodness. If you _really_ knew the right people you could get away with just about anything. Seen it first hand.

I don't mean to rant too much but to put things in perspective, when we built the cabin there was a house a mile or so down the road without running water. It is among the poorest counties in a poor state and is rife with corruption at the county level. To have "international" building codes is a bit of a joke and many of the requirements, especially for a hunting cabin, were simply a joke.

So if at all possible I will daisy chain from the house. I know an electrician who will guide the work that I am able to do and I will pay him to do the rest. It will be done properly and safely.

As an aside, we had to drive in the two copper ground rods for the cabin as well. We have a few inches of decent top soil, a few feet of clay and then rocks or very hard crumbly material. I got one of the eight foot rods down about 5 feet and it wasn't going in any further. I asked a local fellow how he did his and he said he "drove them in with a hacksaw". I thought that was very funny. So both of mine went down about 5 feet and then got lopped off. Not sure it was wise but we've had zero problems in 20 years.

 

[N80]

when I build my 30x40 shop I went with premade trusses. The best part was the truss company delivered them and put them up on the roof. We just had to move them to where they went. I also had them design into the trusses, storage space....so some of the members are bigger than if I hadn't had them design in storage space.

There is some space in the trusses of our cabin. Not what I would call an attic but still usable storage space. I put down some ply-wood for reinforcement. I'm pretty sure the truss spec says not to put anything heavy up there and we don't.

 

[meackerman]

There is some space in the trusses of our cabin. Not what I would call an attic but still usable storage space. I put down some ply-wood for reinforcement. I'm pretty sure the truss spec says not to put anything heavy up there and we don't.

yeah lots of trusses have what looks like storage space. Mine were specifically engineered for storage. I wouldn't store thousands of pounds in mine.
I'd have go find the drawings for mine to see what the load rating is, IIRC it was pounds per square foot (though I could be mis-remembering about that), but what I have up there is way under the limit.

 

[3Ts]

If you want to store stuff up in the attic among the trusses, tell the truss company that and they will design the trusses so you can do so. You will need to tell them how much weight you plan to put up there. I had some trusses made to support 60 #/sqft with a clear span of 24'. Also, depending on the load, some of the truss members may be 2x6 or 2x8 so you'll need to know that if you plan to put a floor on the truss.

 

[jthibodeau89]

So if at all possible I will daisy chain from the house. I know an electrician who will guide the work that I am able to do and I will pay him to do the rest. It will be done properly and safely.

We are also out in a poor county. We bought the property from an estate, so no previous owner to ask questions. Went to pull the septic records to confirm the tank sizes (house has 2 separate systems) and was advised that they don't have records for our property. The 48x108 horse barn has an office with roughed in plumbing including toilet and shower, but no idea if it goes anywhere. We added a 36x66 shop and roughed in a bathroom there, too. Excavation contractor suggested that we just put in a 275 gal IBC tote for a tank. But i think I'll go with a 300 gal septic tank.

If you daisy chain the shop, be sure to run both neutral and ground. We ran a 230V/100A service 230' to the barn with 2-2-2-4 in 1 1/4 pvc conduit to replace the 12/2 direct bury wire that prev owner put in. Had a meter base on barn that was never hooked up.

Also, if you daisy chain be sure that the remote panel is not bonded. My shop has temporary 230V/ 60A service from the barn panel. Both barn and shop are 4 wire unbonded with their own ground rods. Will eventually have a separate 200A service in shop with its own meter. Be aware that shop meters are charged at a different rate than a residence.

 

[newbury]

<snip> Be aware that shop meters are charged at a different rate than a residence.

They tried to do that to me. I've a house on a small hill

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and about 100 yards away the "shops".

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Both have their own meter. One of the buildings in the "shops" has a kitchen, bedroom, and bathroom w/ toilet sink and shower etc. They started to charge us at a higher rate for the shops but I argued it was a residence and the power company agreed.

 

[N80]

Now I’m sure I will not be putting a meter on the shop!

 

[LD1]

Regarding the electric......I think that is dependent on your electric provider.

I have two meters, one at the house and one for my shop. The "fixed" fees are the same. The "usage" fees are more simply because I use less electric. But its the same at the house. In the spring and fall when my usage is down around 1200kwh/month....I actually pay MORE per kwh than in the winter when my usage gets north of 2000kwh/month. And at the shop, my usage is 300-400kwh/month. So it makes sense it cost more. (kinda like buying in bulk and saving)

Regarding the trusses....The only time I have seen single slope roofs is either for much smaller sheds, or for open sided animal barns where having posts in the middle to carry some of the load, where posts in the middle is not an issue for a simple livestock barn.

My 2 concerns for a mono-truss are 1. aesthetics. I think they look cheesy honestly. And as someone else already pointed out...your front wall even with a LOW 2:12 pitch is still gonna be 5' higher.

Second concern that you might not have thought about is the roof metal. You are most likely gonna have to use TWO sheets per run and have a seam. With an overhang, you are pushing a 33' long run of roof metal. And metal that long....even if you could find someone that can make it, is gonna be hard to handle and install without buckling.

If watershed is your only reason for not wanting a common truss....control the water with gutters. Dont know if you were planning on a gutter anyway....but for a single roof pitch sloping to ONE gutter....that gutter now has to carry twice the water as having a gutter on the front and back, with each only carrying water for 1/2 the structure

 

[3Ts]

Second concern that you might not have thought about is the roof metal. You are most likely gonna have to use TWO sheets per run and have a seam. With an overhang, you are pushing a 33' long run of roof metal. And metal that long....even if you could find someone that can make it, is gonna be hard to handle and install without buckling.

I had an 80' wide barn put up with a 4-12 pitch (made it a 2 story barn with a usable loft). The roof panels were about 42' long. I did not do any of the work on the barn. The panels came in on a semi truck and the builder did not seem to have a problem putting them up.

Here in Texas, metal barns are common and there are several companies that have the equipment to take a coil of steel and bend it into the panels for however long you need. The builder waited until the frame was up before he ordered the side wall panels and the roof panels, that way he could specify the length to the inch and he wouldn't have to cut anything.

 

[N80]

@LD1 I hate gutters. Constantly have to clean the ones on the cabin. But, they are a requirement on the cabin due to the layout and slope etc.

With the shop, if it was a shed roof with decent overhang, gutters would not be needed front or back. If I use a typical common truss type roof then gutters will absolutely be necessary on the front. Maybe not on the back

I'm not committed to a shed roof at this point but I still think it would fit the bill best. Not too worried about having multiple runs of the 5V crimp metal roofing. We have two runs on both sides of the cabin roof and there have been no issues in 20 years. If I did a shed roof it would be roughly 17 feet high on the front and 12 on the back. So certainly not too big to manage.

Agree that a common truss, if that is the right term....single ridge line in other words....would be easier for a non-carpenter like me, especially since I've done it before.

Either way, I wouldn't be opposed to renting a boom truck or Lull type fork lift for putting up whatever type truss I end up going with.

 

[jthibodeau89]

Lull type fork truck? Do you mean a telehandler? I.e. a telescoping boom with forks on an AWD buggy?

 

[buckeyefarmer]

When buying trusses you need to spec the live load you intend to put on them, ie the weight of insulation and ceiling. For a house they will probably include live load, for a barn probably not. If you spec floor space built in, it will have at least 30 psf built in. It’s up to you to specify. The trusses will come with the paperwork to show the inspector IF you pay for engineered stamped drawings.