Plan your building with simple sketches of the floor plan and sides, showing the doors, roof, building height, and choose a level, dry and solid area for the building. You may use steel or wood posts or even posts made up of planks laminated together. View lightweight trusses and purlins on Google Images to gain a visual understanding of your options.
Hammer in stakes to mark the four corners and measure corner to corner to make sure the diagonal lengths are exact and the overall shape is perfectly squared. Use string to line up four stakes on each side for your poles. Dig holes, about 800mm wide x 1600mm deep (32 inches x 64 inches), for your posts.
Pour in about six inches of gravel at the base of each hole, pack it down, then pour eight inches of concrete. When dry, set posts into the holes level with each other and brace as necessary. Pour concrete into the holes until slightly higher than ground level.
Affix stringers to the tops of the poles, using appropriate hardware and bolts, after the concrete footings have dried and cured (three to five days). Mount the trusses over the tops of the poles as shown in the references. The first truss will require extra bracing but subsequent trusses will be braced together with attached purlins on the tops of the trusses.
Drill metal roof panels onto the roof purlins beginning from a lower corner. Overlap roof panels slightly, as suggested by manufacturer. Affix a metal ridge cap and side trim to complete the roof.
Make a frame and pour a concrete slab floor if you are planning one. Now that the roof is up it may be poured free from weather worries. For the exterior walls, attach galvanized metal stud framing as necessary. Metal lathe may be used on the long sides where structural poles exist.
Install batt insulation if desired, a plasting moisture barrier and the exterior siding, such as metal paneling. Install the doors, windows and final metal trim at the corners.
Things You Will Need
- Hole digging equipment
- 8 marking stakes
- Carpenter's level/string
- Four 20-foot roof trusses
- Power drill
- 8 Posts
- Metal roofing/siding
- Metal hardware/fasteners
- Metal trim
- Use lighter cold-rolled galvanized steel channels for your trusses and purlins instead of heavier wood trusses or steel joists and you probably won't need to use heavy duty mechanical lifting equipment for the job.