So you think building a shed doesn't take engineering?

It does if you want a shed that's twenty feet wide with no center poles, low enough to fit under the eave of an existing building, and enough headroom that your six foot-four buddy doesn't bonk his head on the rafters. AND, it's gotta be cheap.

The answer is "bar joists". These are frames made of angle iron and rod, that are very strong and don't take up much headroom. Next time you go to Wally World, look up at the ceiling. Those are bar joists.

Bar joists are pretty much standard in size, length, and loadbearing ability. The problem with this is that if you want something different, it has to be custom made, and that costs money. In my case, a joist strong enough to span twenty feet was too tall to fit under the eave of the existing building. Plus, the joistes are designed to have rafters on top of the joist, adding even more height. What I needed was a narrow joist made so the rafters would pass right through the open spaces. And I didn't want it to collapse when we have a freak storm that dumps a foot of really wet snow.

I got out my twenty-something year old Schaum's Outline (kind of a Cliff's Notes for engineering), thinking the answers would just jump right out at me. Wrong. I had to do a whole bunch of cipherin'. It was so tough, it caused my wife to go stay with friends.

When the cipherin' was done, I bought the steel and started the easy part - building the trusses. Three friends helped put up the posts, bolt the trusses on top, and slide in the rafters. They told me the roof was gonna sag. I had the two biggest ones hang from one joist, and the third measure how much it moved. Their combined weight was 551 pounds, and the joist didn't budge. Ha.

Here's the shed, complete with stored treasures:

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