How to Cut Through an Upstairs Floor to Enter a Basement

Decide on a location for the hole in the floor to enter the basement.

Drive a nail through the floor in the desired location using a hammer. Do not drive the nail all the way but just enough so the tip protrudes from the ceiling in the basement. Check the nail tip in the basement to ensure there are no pipes, wires or floor joists directly under the location for the hole. You may need to repeat this procedure several times before finding a good location.

Install a hole saw bit into the chuck at the end of an electric drill. Open the chuck and install the bit, then tighten the chuck. Use a hole saw that creates a hole big enough to accommodate the pipes or wiring but not much bigger.

Hold the drill at a 90-degree angle to the surface of the floor to ensure the hole is drilled straight. Start the drill before placing the bit against the floor. Use a moderate amount of pressure, but do not force the drill. Once the hole is drilled completely through the floor into the basement, back the bit out while it is still spinning to avoid splintering the edges of the hole.