A seesaw can be built with a long board and something to use as the fulcrum. That is all the fun you need for a fun addition to your playscape.
A fulcrum is something that is strong and that the seat can rest on and stay centered. It should be round for a better see saw motion. At a home center you can purchase a round barrel. Be sure the barrel is painted with weather resistant paint. Bury half of the barrel into the ground and let the top half be the fulcrum for the seat. By putting the barrel on its side with half into the ground will keep the see saw in place. Be sure the barrel does not have any sharp edges. The barrel ends should be closed and sealed for safety. It is optional to fill the barrel with sand or soil before burying one half, in order to keep it from collapsing.
A frame built from four inch by four-inch wood can also be built. Be sure and make it strong enough to hold plenty of weight. Another option is to use galvanized steel window wells. They are naturally round in shape. Two added together will make the fulcrum even stronger. Whatever you use it should be safe for all to use. Be sure it is attached to its location securely. You can use spikes that are put through the fulcrum into the ground to hold the see saw in place, if needed.
The seat of the seesaw should be about ten feet long. A board that is about two inches thick will be strong enough not to break. It should not be too wide, as people will sit with their legs on each side of the board. Since the seesaw will most likely be outdoors you will need to get pressure treated wood. You can also paint the see saw, but will have to re-paint it ever few years. Be sure the pressure treated wood is dry before painting. You can also stain and seal it instead of painting it.
The underside of the seat will need two blocks that will keep the seat centered on the fulcrum. These blocks can be a little narrower than the seat. These can be attached with screws or nails. Each end of the seat, where the people will sit, will need a handle for them to hold onto. Using lag bolts, bolt on a piece of wood that is about five inches wide and six inches high, which will be the handle support. The lag bolts should go through the seat and into the handle support far enough to make it safe and strong. Three-inch lag bolts should be long enough. Then the handle can be made from a piece of wood that can be gripped by your hands, such as a two inch by two inch piece. The handle can be about eight inches long and can be rounded for more comfort.
