- 1). Plan the site for your gazebo. Choose a level area away from trees or shrubs, whose roots could grow into the foundation. Mark out a 12-foot square with pegs and string.
- 2). Dig out the square to a depth of 6 inches. This will help the gazebo base to drain properly. Inside the square, measure and mark a 10-foot square. This will be the footprint of the gazebo. Dig a 2-foot deep hole at each corner of the smaller square to site the corner posts. Check that the square has a level base, or the gazebo will not stand squarely and will be unsteady.
- 3). Plant a post in the first corner hole, making sure it is set squarely. Have an assistant hold the post while you fill the foundation hole with Quikrete. Set the remaining three posts in the same way, and leave to set.
- 4). Take the 3 by 8 inch boards and cut both ends off at a 45-degree angle. At one end, cut the bottom point of the angle off to give a flat surface. Position the first board with the flat surface resting on top of the first corner post so that the board extends diagonally upwards into the center of the gazebo. Have an assistant support the board while you nail it into place against the top of the post. Your assistant should continue to support the board while you position the second board. The top ends of both boards should meet and support each other, allowing you to fix the second board in place. Continue until all four boards are in position.
- 5). Fix the 3 by 12 inch fascia boards into place around the sides of the gazebo at the top of the posts to form a rigid square. This will keep the structure stable. As the wood is thick, drill two holes in each face of the post and use screws rather than nails.
- 6). Measure the distance from the top center of the roof join to the middle of the fascia board. Cut four boards to this length, and cut each end to a 45-degree angle. Nail the boards in position as center struts with the help of an assistant. Measure the distance between this strut and the end of the fascia board. Mark the center of this measurement.
- 7). Measure from your marked point to the roof strut. Cut eight boards to this length, and cut each end off to a 45-degree angle. Fix all eight boards in place, two on each side, halfway between the center strut and the corner.
- 8). Fill the foundation pit with gravel and level it off. Plant climbing plants such as ivy, honeysuckle, climbing roses or wisteria against each corner and tie loosely to the corner posts for support.
Source...