Building a deck is a major project that requires serious planning. As with any outdoor project, you must abide by local zoning as well as provincial ordinances and by-laws.

Delineating the perimeter of the deck

Use string and pickets to trace the perimeter of the deck. Be sure that the strings that run from the house are perpendicular to the house. If yours is a two-level deck, delineate both levels.

Building the foundation

When it comes to choosing a type of foundation, consider one of these four options: concrete piers with footings, concrete piers without footings, Dek-Blocks® and screwable foundation posts.
»»  Concrete piers with footings
Dig out 4 in. of soil inside the perimeter. You need to calculate the weight of the deck in order to decide on the number of piers required. If you have drawn your own plan, you may need to consult an expert to determine that. Then, determine the location of the piers. If you’re planning to build the deck at the same time as the house, have both foundations dug at the same time. That will make it easier for you to install formwork (54 in. deep) and pour the concrete.

Concrete piers with footings

If your deck is an addition, it will be easy for you to dig 54 in. deep holes using a posthole digger. In such cases, use pre-fabricated circular footings which adapt to circular forms of varying diameters and in which you will pour the concrete.
Using 2 x 8 pieces, build square forms work of 24 in. per side, 8 in. deep. Lay in a reinforcing rod (diagonally) and add wire mesh.
Stand an L-shaped reinforcing rod in the centre of the frame, placing the short end of it under the diagonal reinforcing rod. The L-shaped rod will serve as the link between the footing and the pier. Hold it erect as you pour the concrete. Be sure to comply with the concrete manufacturer’s instructions on curing time.

Place tubular forms (Sonotubes®) on the centre of the footings and hold them up with pieces of wood. Use a level to ensure the tubes are vertically levelled. Nail the tube to the footing at a 45°, from the outside of the tube into the footing.
Backfill the footing using the original soil. Use a long narrow object to slowly stir the concrete to the bottom of the tube, making sure the concrete remains homogenous and free of air bubbles. Before the concrete sets, insert, in the centre, the rods to which beam brackets will be attached later. Be sure to comply with the concrete manufacturer’s instructions on curing time.

Concrete piers without footings

Dig out 4 in. of soil inside the perimeter and determine the location of the piers. Use a posthole digger to dig holes 54 in. below the surface of the soil.

Insert tubular forms (Sonotubes®) in each hole. Use a carpenter’s level to ensure the tubes are on the level and at the same height so as to minimize adjustments later. Pour the concrete in the frames. Insert a steel rod in each frame to reinforce the pier and minimize damage caused to the structure by frost. Install beam-retaining brackets. Be sure to comply with the concrete manufacturer’s instructions on curing time.

Dek Blocks ®

Dig out 4 in. of soil inside the perimeter.
Determine the location of the Dek-Blocks®. Dig holes, 12 in. deep, 24 in. x 24 in., for a total of 16 in. in depth. Fill the holes with 3/4 in. gravel, in three successive coats of 4 in. which you will compact using a vibrating plate or mechanical compactor. Spread a geotextile sheet over the entire excavated surface and lay the Dek-Blocks® in place. Backfill the entire perimeter using 3/4 in. gravel.

Screwable foundation posts

Purchase screwable posts and determine the location of the posts.
Insert a beam in the pillar-supporting bracket at the top of the stake to screw the posts into the ground, below the frost line and attach a pier to the bracket.