After the sills are set on 1" X 2" X 11" temporary wood blocks, make sure they are absolutely level and square. This is the most important step in the assembly of the greenhouse structure. Take several measurements down the length of the greenhouse, to verify that the dimension from inside face of sill to inside face of sill is correct, and exactly the same at each location checked. Also check diagonally from corner to corner. These dimensions should be the same. Make sure spacing between gable and/or side door sills is accurate.
Stretch a taut string down the length of each sill, and verify that it is level and straight. Do this three times: (1) after the sills are placed in position on the wall, and toe-nailed into position (2) after the structure is erected (3) after glazing, before cementing in the sill anchors.
Install the roof bars, side bars and eaves first. Do NOT erect the end rafter(s) until after vent shafting is installed. (D) (For non-curved eave models, assemble the roof and side bars with splice plates furnished.)
Install the ridge next, then the vent header(s). Slide the vinyl plastic into the groove on the bottom of the vent header, before installing the header on the roof. Snip out excess plastic where the header crosses the roof bar. Attach glazing clips to bottom of header - see vent sash assembly page near the end of instructions.
The position of the vent header down the roof from the ridge is determined by use of gauges: hook the end with a diagonal cut over the leg on the bottom of the ridge, and position the upstanding leg of the vent header in the notch on the lower end of the gauge.
Slide the vent shafting through the holes in the roof bars, installing and locating the arms and rods in accordance with the assembly drawing. Note also where the manual gear is located, depending on length of greenhouse, and install gear at correct location. Then install the gable end rafter(s).
Assemble the roof sash on the ground in two or three section lengths. Do not attach the muntins at splice locations at this time. Assemble sash top rail, so slots match pins in ridge. Lift the sash assembly into position on the greenhouse roof, and hook the sash top rail into position on the ridge in two and three section lengths. Then splice the sash sections together, and attach the muntins at splice locations.
After the greenhouse is fully glazed, and the sills ready to be grouted, move the door closures snug against the masonry, and attach to the wall with angle lugs provided, drilling through the wall for installation of Rawl plugs.