A sump pit is little more than a hole in the ground used to gather water. The most common residential applications are in basements and crawl spaces. Normally a sump pit houses a sump pump, which automatically pumps the water out and away from the residence. While sump pits themselves are quite basic, proper planning and preparation will help ensure trouble free operation.
Determine the proper location for your sump pit. Ideally the pit will be located at the lowest portion of the basement, crawl space or other area where unwanted water gathers. Locate the sump pit away from traffic, such as in a corner or against an exterior wall. Mark out a square approximately 24 inches across.
Excavate the area to a depth of approximately 33 inches. An electric jack hammer is a good tool for breaking through concrete flooring. Work slowly to help reduce damage to the surrounding concrete. Once through the concrete, remove the dirt and make certain the sides of the pit are smooth and free of obstruction.
Build a wooden frame 30 inches high by 18 inches square. At the top of the frame add a one-inch lip, which will create a seat in the new concrete on which the pit cover will rest. While you can use any type of wood, the smoother the outer surface, the better your results will be. The frame must be sturdy and strong enough to hold the cement in place until dry.
Mix the cement in the wheelbarrow, keeping it at a fairly thick consistency. Once the concrete is thoroughly mixed, poor enough into the pit to form a 3-inch floor. Carefully smooth out the surface, then place the frame into the hole, letting it rest gently on the wet cement. Keep the frame centred and level, allowing 3 inches on all sides. With the frame in place, fill the outer area with cement until it is level with the existing floor. Smooth the concrete to fill any cracks or damaged areas left by the excavation process.
Remove the frame after the concrete has dried for at least 24 hours.
Construct a pit cover to help prevent anyone from accidentally stepping into the sump pit. A heavy metal grate is a good choice because water can pass through, yet it is sturdy enough to support the weight of an adult. Cut the grate to the finished size of the pit opening and allow it to rest on the one-inch inset left by the frame. This will allow the grate to be flush with the existing floor to help prevent trip hazards.
Keep the bottom of the pit as smooth and level as possible.
If the basement is wet or has standing water, use extreme caution using electrical devices such as the electric jackhammer.