A slide is one of the most common features on a children’s playground. It is basically a smooth slope with ladder on one end, soft landing surface on the other and slightly folded sides to keep the child from falling over. Slides may be simple and straight but can also have a more elaborate, wavy or spiral shape. While slides in public playgrounds are mostly made of composite materials, plastic, fiberglass and metal, a backyard slide is best made from wood and metal.
Cut thick 3-by-4 wooden posts for the slide’s supporting structure. Measure and mark height of the posts from the ground to the platform at the top, but also add 3 feet for the foundation. Use a power saw and cut four identical wooden posts for the platform.
Mark the four posts on the ground with spray paint where you are building the slide. If there are any distractions on the ground such as plants and rock, remove them before installing the slide. This structure will be dug into the ground and is thus semipermanent and immobile, so choose the location wisely.
Dig four holes in the ground, in the places you marked. Use a hole digger for this task or a pointed shovel. Make the holes around 3 feet deep and 2 to 3 feet wide.
Pour around 5 inches of fine gravel into the hole. Place the post into the hole and screw in the wooden braces to support the post. Pour fast-setting concrete around the base of the post. Be sure to leave around 5 inches of space to cover with soil later. Use a level to ensure that the posts are absolutely vertical. Repeat for all four posts and leave the concrete to cure for around six hours. Then attach horizontal 2-by-4 wooden elements around each post to connect them and create a ring that makes the whole construction rigid and stable.
Construct the platform at the top of the four posts. Use 1-by-4 and 2-by-4 wooden boards and deck boards to assemble a sturdy and secure deck. First make a frame from the 2-by-4s and then add the 1-by-4s for the floor, across the frame. Attach the elements with screws and then mount the whole deck onto the wooden ring.
Add a rail and pickets to the edges of the deck, using 3-by-4s for four corner posts, 2-by-4s for the top and bottom rail and 1-by-4 for the pickets. Make a hole on the side of the slide, adjusted to the age of the child. On the opposite side, make the same hole, with or without the top rail.
Attach a plastic slope below the hole in the hand rail, making sure to mount it securely and firmly to the deck. These ready-made plastic elements can be purchased in a garden supply store and usually come with an installation kit as well. Use the screws from the installation kit and follow the instruction for attaching the slope to the deck.
Add a small ladder on the opposite side and little plastic handles on the hand rail above the ladders, to assist the children when climbing on the deck. Note that the ladder can be gently sloped or vertical. Also, add a metal tube at the top of the hole above the slide itself for the child to hold onto before sliding down.
Treat the wooden surface of the structure with wood primer and wood paint of your choice.
Paint the wooden structure of the slide into a bright color to match the brightly colored plastic slope element.
Do not spray silicone over the slide’s plastic surface, since it might make the child go too fast down the slide, resulting in injury.