Installing fence posts can be a difficult and gruelling task. You first must choose the post style, align a perimeter for your fence, dig the holes, and then slowly pack dirt in and refill the post hole while keeping it level. So why not eliminate one of those steps and use a product that doesn't erode away like dirt? When it comes time to refill the fence post hole with dirt, you can use expanding foam as a quick and easy method for securing your fence post into the ground.
Shape out a hole with a diameter that's 7.5 cm (3 inches) greater than the diameter of the fence post. Using the posthole digger, make the hole 75 to 90 cm (2.5 to 3 feet) deep and pile the dirt a couple feet away form the hole.
Place the fence post in the hole. Pry the top towards yourself. Stand the pole up straight against the other side of the hole. Use the level to make sure the fence post is as straight as possible.
Use a broom handle or dowel to pack soil around the base of the fence post in the hole. Slowly scoop the dirt into the hole and tamp it tightly around the fence post between scoops. Pack approximately 7.5 cm (3 inches) of soil around the base of the fence post or until the post can stand upright on its own.
Attach the spray nozzle to the expanding foam can. Spray the foam closely to the base of the fence post in the hole, and slowly fill the base and hole until the hole is halfway full of foam.
Allow for the foam to expand and dry for 8 hours.
Remember to only fill the hole half way full of expanding foam, because it will double in size after expanding.