Building a Garden Shed & High School Geometry

When we built our little barn a few years ago, we had a 12'x12' concrete slab poured and built a building with a loft and a slanted roof. This was supposed to house the Gravely, the ATV, the tiller, and other gardening stuff. Then we built a work bench and got a table saw and a miter saw. I wanted a workshop, but it was too crowded with all that stuff in the barn. Subsequently, I built a 8'x12' lean-to shed next to the barn, and that's where the ATV, Gravely, and ATV trailer are stored. Now we have a chipper-shredder and the tiller, and these are really difficult to transport up to the garden and back down. Both pieces of equipment have been sitting outside up by the garden most of the summer. Exposure to sun and rain will take a toll on equipment, and so the obvious thing to do was build a shed dedicated to storing garden equipment. Then the barn can become a dedicated workshop.

Figure 1. Shed Plans (6'x8')

I found a nice set of shed plans (Fig. 1) on the Mother Earth website, and altered them slightly from a 6'x8' shed to an 8'x8' one. When I got to West Virginia this past Wednesday, the ground was perfectly dry, so my hope was that I could haul construction materials up to the garden clearing with my truck. Between late Wednesday and early Friday it rained 1.27", turning the road into a muddy mess. No chance of getting the truck anywhere. I went ahead and ran to 84 Lumber in Elkins and got the 2"x6"x8' floor joists, a 4"x4"x8' post for the supports, concrete piers to support the shed, and two sheets of 3/4" treated plywood. This is so easy with the full bed on the truck: everything just fits flat on the bed with no need to tie anything down or have anything stick out. As expected, I got the truck into the house clearing but not up the road. I got the boards up to the garden just by stacking them on the front and back ATV racks with the concrete piers in the trailer. The plywood was another story. Eventually, I figured out that I could take one sheet at a time, lay it cross-ways on the back ATV rack with the front laying on the seat. I sat on the wood to hold it down and drove very slowly up the road, eventually getting both pieces up. Treated plywood is very heavy, particularly because it was waterlogged from sitting in the back of the truck in the rains. It was way too heavy for me to pick up.

Figure 2. Roughed-in Framing and Piers.

The first issue in setting 12 concrete piers is getting a perfect square and having them completely horizontal (level). Given the fact that there isn't a level piece of ground on the entire 87 acre property, this required lots of digging for the uphill piers. They were sort of roughed-in, and the 2"x6" frame was set on them.

Figure 3. Frame and Joists.

Getting framing into a perfect square or rectangle is a non-trivial process. The lengths of the boards are easy to cut accurately, but putting them together in a square is not.  Most often the frame is a slight parallelogram, and this means the floor and walls won't fit properly. You have to use some of that long-forgotten high school geometry, and the Pythagorean theorem. The two diagonals will be identical in a perfect square or rectangle, as they represent the hypot-enuses (yes, that is the plural of hypotenuse) of two separate right triangles with all sides 96", so the corners are adjusted until this is the case. The above picture (Fig. 2) shows the result: 2"x6" framing set on concrete piers in a perfect square.

After getting the frame square, I added the joists, 24" on center (it's only a shed, so no need for 18" on center joists). All connections were made with 3 1/2" deck screws. The entire base is treated pine, as it will be on or near the ground. The framing was tied into the 4"x4" supports with 3/8" galvanized lag bolts (Fig. 3).

Figure 4. Base of Shed with Floor.

The plywood was dragged onto the frame and a final check on the squareness was made. The plywood was fastened to the frame with 3" deck screws. The end result came from about six hours of labor. Lots of heavy lifting. This is the base of the shed (Fig. 4).

Construction of the walls required a nail gun, so they were assembled in front of the barn and hauled up to the garden. The two side walls were trivial, 96" wide with studs 24" on center. There was a small snafu, though, and that was because I had no 96" long 2"x4"s. Studs are 92 1/2" long because they fit inside a frame of 2"x4"s. The solution was to splice a 24" piece onto a 72" piece using a brace, and this is what you can see along the top and bottom of the walls (below). The back wall will contain a window, so this was framed appropriately leaving a 24"x36" hole for the window. This can be seen on the back wall. One item that we could envision storing in this building is an ATV mower, most of which are around 54" wide. Thus, the door needed to be 60", and this left little space on either side of the door. The side frames were double 2"x4"s, and the lintel was just a 2"x4" on its side.

Now these walls are all about 8'x8' and quite heavy. The ATV trailer is only 36" long including the tongue, so balancing the walls on this small trailer seemed impossible. Fortunately, I have a 5'x8' trailer for the truck, but I was uncertain if the ATV would haul it. In the end, I stacked three of the walls (not the one with the door) on the trailer and strapped them down. With considerable trouble, the ATV managed to haul them up to the garden. The wall with the door was hauled in a manner similar to the plywood, using the ATV trailer. By this point, you can see how many times I ran the ATV up and down to the garden, and the poor dogs trailed along each trip.

Figure 5. Walls Attached to Base.

Installing the walls proved trivial, once they were set-up on the platform properly. They were screwed to the floor frame and to each other with deck screws, and they fit perfectly. They were even plumb, plus or minus a bit (Fig. 5). This is the point at which I ran out of materials and time.

This is a view of the shed so far, with the 60" door in front and the window in back. Next step is to add siding and the roof joists, but that will be next trip.

UPDATE 9/26/13

I built the rafters and installed them with 6" screws and hurricane straps (Fig. 6). The siding is 5/8" T1-11 siding is really heavy, but I managed to get that up and nailed securely. Most of the connections were made with 2"/3"/3.5" deck screws as there isn't any power for the pneumatic nail gun. Furring strips were installed in preparation for the metal roof.

Figure 6. Rafters, Siding, and Furring Strips Installed

FINAL UPDATE 1/14/14

The doors were mounted and the shed trimmed using treated 1x6" lumber, ripped in half. The shed was stained in late October, this time by hauling the generator up to the garden and using a power paint sprayer. It took longer to set-up and clean the painter than it did to paint (Fig. 7).

Figure 7. Stained Shed w/Doors

The metal roofing came in later that week, and was installed without too much hassle. I got it on mostly correctly, but this is the first time I've installed this sort of roofing, so it isn't too bad. I don't have a picture of the final product, but one will appear soon.