Measure the PVC pipes with measuring tape, and use a pencil to mark the measurements. Draw on the 5-foot pipes, two pipes to at 40 inches and two pipes at 16 inches. Draw a pencil mark at the measurements.
Align the PVC pipe cutter blade with the pencil line and cut on the inside of the line. Rub sandpaper on the edge of the freshly cut pipe.
Create a rectangle with the pipes from step 1, using four three-way L fittings to keep the corners together; this is the towel rack’s base. Apply PVC cement into the fittings to keep the pipes from slipping.
Measure and cut four PVC pipes to 36 inches out of the 6-foot pipe, the same way as in step 1 and 2. Insert the 36-inch pipes into the top of the three-way L fittings from step 3.
Push one tee fitting on all four of the 36-inch pipes, and center them on the pipes. Turn the fittings so that they face the opposite side of the rack long ways, since these fittings will hold a lower-tier towel rod.
Cut two pipes to 40 inches from the 4-foot PVC pipes. Insert the pipes into the tee fittings from step 5, with one tee fitting on each end of the pipe.
Cut two more pipes to 40 inches and two more to 16 inches, out of the 5-foot pipe, like in steps 1 and 2. Assemble another rectangle on top of the 36-inch pipes with four more three-way L fittings.
Put the PVC towel rack in or any room you like and hang towels over the 40-inch pipes from steps 6 and 7.