Step 6: Framing the Roof and Installing the Purlins
To make a long story short, the first step was to erect the ridge pole which is a 14 foot long piece of 2 by 6. Then, each 2 by 4 rafter is put in place on 24 inch centers and secured both to the ridge pole on top and the wall's top plate on bottom. A strip of 1/2 inch plywood was secured along each side of the ridge and another strip of plywood run along the bottom edge of each side of the roof. This plywood serves as an attachment point for the glazing and to hold the roof square.
The rafter tails overhang the walls by one foot. The facia and soffit are dressed in 1/2 inch plywood.
The roof and walls are all dressed in purlins which are the horozontal members that are used to support the glazing and serve as an attachment point. They are made from 8 foot long pieces of 2 by 6 lumber ripped down into 3/4 inch strips. This method is way cheaper than buying the strapping from the store. All that was needed was a table saw and some patience.
Finally, corner braces were added to each corner of all four walls for a total of 16. These are necessary to hold the structure stiff and square since there is no sheeting to handle that task. The ridge pole was also supported by a diagonal brace on each side to help hold the roof square. The final structure is as stiff and solid as a rock.