Shed trusses and snow load capacity

I'm working on a 3 sided run in for livestock, and had previously been using traditional 2x8 rafter construction for the roof. I came across these designs, and am very intrigued at using this 2x4 truss system instead. One thing I don't see mentioned though is roof load capacity. I live in Michigan, and have to account for snow load in addition to just the weight of the roof. Are 2x4's with this construction able to withstand additional snow load? Ground snow load for my areas is 25psf. Roof pitch will be 3/12, span of roof is 12'.

I looked at the 3D model of your 16x12 shed as well, with this style roof. In the model it looks like you added collar ties on all the trusses. Is that for additional load capacity or another reason? At what point does the need for collars become necessary? I'm planning on doing a 24'x12' structure, and thought about buying and adapting those plans to my needs, but wanted to ask about the snow first.

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Aug 17, 2019
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2x4 shed truss system and snow load capacity
by: John

Hi,

I'm not sure I can adequately answer your question about snow loads since I don't have those figures for my sheds. Your main concern with the truss system is to be able to stop your shed walls from spreading so it's important to either have ceiling/loft joists spanning across from wall to wall and connected to your truss bottoms where they rest on the top plates, or use them in conjunction with collar ties. As for the collar ties, I recommend those where you cannot place ceiling/loft joists. However I don't recommend using just collar ties with no ceiling/loft joists at all.

Safety is my number one concern with my shed plans so I always recommend submitting the plans you buy from me to your local building inspection department for a permit. You can make changes on the plans for things you want to add/delete. Most local building departments will make notations on the plans that require you to do or make certain modifications in order to pass inspections.

Most shed construction shown on my plans is identical to typical house framing. If you have for example a ranch style home with gable roof framing that is built with a ridge board, 2x4 rafters spaced 24" on centers with 1/2" roof sheeting, then you can get an idea of what your local building codes are.

If you buy a set of my plans that do not have a ridge board and want to add one, its just a matter of subtracting 3/4" off the inside vertical top of the truss. You can also swap out the 2x4 truss members to 2x6, and space them 16" on center.

I hope this helps clear up any confusion about your snow load question. I can tell you that most roof configurations that show a ridge board for the roof framing will not require a snow load rating (at least for 12' wide sheds). That has been my general experience anyway.

If you have any more questions, please email me shedking@gmail.com

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