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Math Fail! Anyone want to design me a garage?

Rednecktek

Solar Wizard
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Sep 8, 2021
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On a boat usually.
So I need to build a building up at the camp to house the new mini excavator and have space for a small utility/laundry room. The problem I'm having is that me and Trig are NOT friends and I don't know how to calculate the width of the building. All I know is that I want 10ft walls and I want to use the 10ft sheets of steel roofing, either 1 row or 2 if 1 row is too narrow. I am coming up with insane numbers that are different every time I try to calculate how wide the building can be and still deal with snow load and such for Eastern Washington.

It'll (unfortunately) most likely be east/west facing slopes (stupid terrain) so solar panel weight isn't a huge deal, although extra points if it's strong enough.

Anyone architects around here want to earn a couple hundred bucks designing the building? PM me and I can give you what I've got.
 
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No architects in the house? :cry:

I guess I should add my plan is to do post & beam then frame in the back end for a laundry/utility room if that means anything. I'll need to get full plans if possible.

Anyone?
 
How much overhang do you want and do you have snow load? Is there any other reason you would want a higher pitch rather than a low pitch?

I think the minimum pitch for the metal sheets is 3:12 to prevent leaking. So in plan a 10' panel would span 9'-8 3/8". If you have a gable vent at the top then that adds an inch or so of width on each side. Your facia-facia width would be 19'-3" with a 1/2" drip edge. Subtract out your overhangs on each side and wall thickness for interior width.

Formula is sqrt(rise^2 + run^2).
 
I only need to worry about snow load 4 months a year. ? Anything over 6" of overhang is gravy. My plan (hope?) is 6x6 post and beam with 2x6 for the roof (Joists? That's not the right word...) and hoping for about 24ft deep and I'll just frame in the back end so don't count it.

Unfortunately Trig and I don't get along.
 
what Is the overall size of the building
That's what I'm trying to figure out. I'm hoping for 24ft deep but I don't know how wide I can get with 10ft and 8ft sheets of roofing steel. That will determine the width. Cutting it straight is a real PITA so I'd like to use full sheets, but the only information I can find for snow load is that 50lb and 110Mph are the county requirements.

What I'm hoping to do is get in the neighborhood of 10-16ft of width using uncut sheets (either 2x 10ft or 10ft + 8ft or 2x 8ft) but I can't figure out how tall the center post needs to be and how wide the structure will be. Hence looking for an architect who can do all the math before I just get a pile of lumber up there and guesstimate.
 
You don't have to cut the sheets; just let them overlap more. How wide would you like the garage to be inside? There are plenty of options once you set at least a few basic parameters.
 
With a 3/12 pitch your center would be 54 inches each rafter would be approximately 17ft with a 6 inch overhang on a building 30 ft wide
 
A decent architect won't work for a couple hundred bucks. Besides, you don't need an architect, or trigonometry. All you need is a ruler and some paper. 1/4" = 1' is a good place to start.
 
ProTip:

Btw. there is many, many garage prebuilt kit suppliers on the net.
Find a model which seems to cover your needs and copy the layout like a M.F.! :)
Profit. ^^
 
Having lived and built in Washington State many decades past my experience tells me that you will either need to submit a standard pre-approved design or need a licensed architectural/engineer stamp for your trusses. I found it was easiest to simply buy pre-built trusses with the company giving the necessary paper work for the building department approval.
 
You must be planning to put solar panels on your roof. Your first concerns should be building orientation and roof pitch. Having defined the roof pitch, we can tell you garage width for every 10' of roof.
 
I was assuming you were doing a standard truss design with 1 8ft and 1 10ft sheet per side if you are doing a mono truss (just one slope) it would be 15 ft, as Mattb4 said unless you are doing this rougue ( farmer style ) you will have to check with the county building inspector, ferry and stevens county’s I believe may be a little more relaxed than king or Spokane for example assuming you are in that general area from previous conversations but remember we are living in a nanny/communist state so have your current colonoscopy and any other documents ready for inspection and a thick wallet it costs a lot of money to have these people regulate your life
 
You must be planning to put solar panels on your roof. Your first concerns should be building orientation and roof pitch. Having defined the roof pitch, we can tell you garage width for every 10' of roof.
Nope, need a place big enough to park a mini excavator and make a small laundry room. Topography makes solar panels useless at the site.

I was assuming you were doing a standard truss design with 1 8ft and 1 10ft sheet per side if you are doing a mono truss (just one slope) it would be 15 ft, as Mattb4 said unless you are doing this rougue ( farmer style ) you will have to check with the county building inspector, ferry and stevens county’s I believe may be a little more relaxed than king or Spokane for example assuming you are in that general area from previous conversations but remember we are living in a nanny/communist state so have your current colonoscopy and any other documents ready for inspection and a thick wallet it costs a lot of money to have these people regulate your life
I was planning on a basic shed style with a single 10ft sheet on either side of the peak and trying to figure out how wide the building would be.

Fortunately this is WAY off grid so permits aren't required for under 600sq ft and I'm looking at about 300sq ft-ish by rough napkin math. Gotta love Pend Orielle!

Looking up some various plans it looks like I could go as wide as 16ft and still meet the 50lb as long as my trusses are close enough together (thanks LydMekk) and I'm rethinking the amount of work this is going to take. Because of the insane price of lumber still for treated 6x6's and 4x6s and the length involved, I might just get a Home Depot shed and some extra 2x4's to bulk things up a bit. It looks like 8ft steel will fit nicely on that.
 
a2 + b2 = c2
Roof pitch allows you to calculate the ridge height. For example a 4/12 pitch is 4 in up for every 12 inch over.

Easiest thing to do is decide on a width. Lets say 12ft wide. Half of that is 6 ft therefor a 4/12 pitch roof means the ridge is 6 X 4in =24 in.

2squared=4 6 squared=36, 4+36=40 the square root of 40= 6.32ft A 8ft sheet of steel will do this and give you 1.68ft of overhang.
 
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