Building the main frame
Measure exactly 950mm from ground level and cut each post to height. This can be done with a portable skill saw or a hand saw. Make sure you keep the saw straight as you cut. Measure and mark the required height on all four sides of the post. Use these marks as a guide as you cut.
Attach the lengths of 45mm by 65mm timber to the tops of the posts as shown in Figure 3.1.
Use construction adhesive in the joins, as this will provide a stronger bond. Nailing these can be difficult. It can help to have an extra person to help hold them in place as you nail. Nail diagonally as you did for the timber around the edge of the floor.
Decide where you want the door. Attach the 770mm length of 45mm by 45mm timber vertically as shown in Figure 3.1. Make sure it is 250mm from the nearest post.
Then attach the 250mm length of 45mm by 45mm timber. Attach it 250mm from the edge of the rim around the floor as shown.
You should have formed a square 250mm by 250mm which will become a door later.