Closet Flange

• Toilets are held to the floor by a piece of plumbing called a closet flange and two concealed bolts. The flat, circular, floor-mounted flange with screw and bolt holes got its name from an old term for a toilet: the water closet. Closet flanges may be made of metal or plastic. In addition to holding down the toilet, the closet flange also forms part of the joint between the toilet’s waste outlet and the floor drain that carries the waste to the sewer.
  
  

Installing the Flange

• To mount a toilet, you first join the closet flange to the drain pipe by solder or cement, then fit it with two vertical closet bolts that will anchor the toilet in place--the bolts fit into edge slots on the flange. Next, secure the flange to the floor with wood screws or self-tapping concrete screws, depending on the floor type. If you're replacing an old toilet and the old closet flange is still in good, uncracked condition, you can reuse it, but you probably will have to replace the closet bolts. Closet flanges come in sizes to fit 3-inch or 4-inch drains. Flanges and closet bolts are sold at hardware stores and home improvement centers.
  
  

Setting the Toilet

• Once your flange is in place, you must place the seal that will render watertight the joint between the toilet elbow and the closet flange. The seal consists of a ring of sticky wax that you stick to the closet flange. Wax seals come in sizes to match the flanges, and are sold at hardware and home centers. With the seal stuck to the toilet flange, lift the toilet up and over the closet flange. Make sure the mounting holes at the toilet’s base line up with the closet bolts, and set the toilet down over the closet flange and press down with light force to seat the wax sealing ring.
  
  

Floor Mounting

• With the toilet bowl in place, slip a washer and nut over each of the exposed closet bolts and hand-tighten the nut. Complete the tightening by alternately tightening each nut 2 or 3 turns with a wrench until the toilet fits snugly to the floor. Complete the mounting job by cutting off the excess length of closet bolt with a small hacksaw and concealing the hold-down nuts with plastic trim caps that match the color of the toilet. Depending on toilet model, you may also have to attach the water line, water tank and flushing mechanism to the bowl after securing the bowl to the floor. That’s it. Your toilet now is held tightly to the floor and you can’t see what’s holding it down.