Pre-fab trusses for shed style shop?

N80 · Dec 22, 2021

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.

duffer · Dec 22, 2021

N80 said:
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.

Sure. Any truss company can make shed roof trusses. Easy peazy. I just got done quoting a shed roof design for a 4 car garage/shed my neighbor wants to build. Depending on the slope you want (1½:12, 2:12, etc) cost will vary, along with the length you're wanting. I planned on 2' OC spacing, and using 5/8" sheathing for the roof, or better yet, use the zip system for the roof, then add shingles or metal.

Quoted 24 common trusses, and 2 end trusses, 32' long, with 2x4 chords top & bottom, was $3350

tfuller · Dec 22, 2021

Here is a place in Augusta, GA that should be able to help you out Armour Metals

3Ts · Dec 22, 2021

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.

1) Yes, 30' is not that big of a span for engineered trusses.
2) No, I did mine over 10 years ago so what I paid won't reflect todays prices with all the increases over the years.
3) Yes, BUT! It is feasible to make your own but I found that the truss company could do the load analysis, make them and deliver them on site and certify the drawings for the inspector, for a little less than I could buy the lumber (from a big box store).

N80 · Dec 22, 2021

@duffer Excellent info. Looks like my costs would be similar to your quote and that's really not bad and seems low enough that making my own would not be worth the time and effort (or the inferior product if I make them).

@tfuller Thanks for the link. Had not thought about metal but it seems worth looking into it.

@3Ts Agree. Looks like making my own would not be worth it.

As usual, great info from TBN members.

PILOON · Dec 22, 2021

I have built a few sheds using prefab trusses.
The specs for sheds/barns/garages are less than for homes and much more affordable.

In fact I cost compared DIY vs prefabbed and simply could not justify DIY based on materials alone since they use up all those bits and pieces that we'd otherwise simply trash.
Also they make them on a huge jig table and hydraulically ram the plates in better than we could do manually.
Plus each one is an exact copy of the first.
Another bonus is they only use KD #1 wood therefor much lighter.

In my area most yards stock a range of prefab shed/garage trusses.
The last one we did was for a 24 x 36 building.

jthibodeau89 · Dec 23, 2021

tfuller said:
Here is a place in Augusta, GA that should be able to help you out Armour Metals

The metal shed sttle trusses are not shown in 30' span. Perhaps they can build custom. The steel trusses are usually placed on 10-12' column spacing with 2x6 purlins for pole barns. Not the same structure as wooden trusses, but can be adapted to stick frame walls on a slab. Would need 5 steel trusses for a 40' wide building

buckeyefarmer · Dec 23, 2021

When I needed floor trusses to span my garage I just went to the manufacturer and they designed them for me. Same with roof trusses.

Egon · Dec 23, 2021

Go to a few suppliers and get Quotes. They will be able to design and build the trusses for you.

Prefabbed is the way to go. Building them you’re self involves setting up jigs and lots of angled cuts. The cost will probably end up the same as self built or even lower.
At thirty feet you may need equipment to place the joists. Again an area that may be easier/quicker done by an experienced crew. A slightly crooked roof can be real fun when the roofing material is applied.