The New Shop – To the rafters

Vacation is over, so it’s time to get started on Phase Two. That means it is time to cut and assemble the roof rafters, build the walls, and get this thing to get on a 3D level.

It started with calculating the roof pitch. I used an online calculator to help me out, and I went with angles and lengths equal so that I wouldn’t get trapped in stupid mistakes. I did make a mistake that cost me a few bucks, but I’ll get to that later. I used a 45 degree sweep for the rafters and calculated that my roof height would reach six feet off the walls.

Calculations complete, first up was cutting the gussets. I went with a two foot width to maximize material use. They were 8.75″ high. I bought three sheets of 7/32″ OSB and brought them home in the back of the van. The plan was to use my parallel guides to cut to height, then crosscut to length. Unfortunately, I can’t get to that narrow of a cut – about 12″ is my smallest. So I cut to about 15.75″ for all of them, and ripped them in half at the table saw. An added step, but it worked well. I then crosscut them all at the miter saw to about 24″ across.

That complete, it was time to cut the peaks. I hadn’t planned on how to do this except for drawing lines and cutting with the circular saw as is custom. I did notice though that my miter gauge went to 22.5 degrees, thus making the 135 degree peak possible. I set up the stop on the gauge and this went really fast. It was still a chore, but I figure I spent perhaps a third of the time doing it this way than with the circular saw. Repeatability is everything. A couple hours after I got home all 54 gussets were cut and stacked ready for the next step. Friday evening was in the books.

Saturday morning I got up and headed to the big box store for some rafter material. I picked up 20 2x4x10s for the inside rafters and started to look at the plans. I decided to cut a bit long so that I would have an inch or so overhang outside, to help water dispersal when it rained. But when I put it together on the shop floor, I came up way short. Where did I go wrong?

Well, two issues. One was that my miter saw hadn’t been set up at 22.5 degrees, but around 18. Also, when I made my plans I forgot to adjust the rafter depth from 4″ to 3.5″. Thankfully, I had only cut one board too short instead of two or all. I tested my next two boards with the corrected measurements and it came together well. My template appeared to be off-kilter, but it did not impact how it all came together. I then went back to the store to buy my replacement board plus the overhang I planned for the entry.

I set my miter saw up with a stop block at about 57″ and cut all boards to that length, getting two spans in those 10′ boards. I have enough scrap blocks at a decent length that I think those will make my overhang. I then set the miter saw at 22.5 degrees (this time) and set an angled stop block. I had to cut on the right side for the first angled cut, flip it over, slide it down, and cut to final size. There were 48 of these trapezoidal boards ready to assemble into rafter hoops. I used scrap to screw down into the new shop floor for my template and all the boards seemed to match up well. Not super perfect in spots, but good enough.

Trying to keep costs to a minimum, to nail the gussets on I wanted to use more of these galvanized 2-3/8 nails I bought to install the floor. But that meant if I installed one side of the gussets I would nail the entire thing to my floor, so I set up the opposite side gussets at the same time and nailed through both. Even then the nails poke out just a touch, but won’t impact anything as long as I don’t scrape my face when in the loft. I stood up the rafter assemblies and nailed a couple more on each one from the back side for good measure. These things are strong. What isn’t strong is the Johnson ties I tried to use on the outside rafters. I didn’t expect them to bend so easily, and I’ll be returning the ones I didn’t use. I’ll just nail these directly to the siding. Or some other solution. Or I make a couple more gussets, as I have a scrap piece of the OSB available.

Next up is making the walls, and things are going to get real, real fast. I’ll be using Sketchup this week to try and avoid any surprises, as I’ve been doing every step of the way to this point. I am digitally modeling the entire shop in every detail, and I have gotten caught up to the complete floor to this point. Now that the rafters are complete I can accurately model those and have them ready to put on the walls. Now I can model the walls with every stud and mark out exactly where the windows and doors will go. I’ll post an update with the digital model in a few days if I remember.

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