A shower pan is a pan that is placed below the floor tiles or below the concrete base of the shower. It helps prevent water leakage from the shower. It constitutes the floor of a shower, providing it with a firm base to stand. It is provided with a non- slip surface.

It is an indispensable part of bathroom furnishings. When installed properly, it directs all the water from the shower into the drain. Shower pans can be made from a variety of materials; synthetic such as fiberglass and acrylic or from other materials that are durable, strong and waterproof. They are also made from composite molded materials, which make them look like stone or marble. Some shower pans allow for tiles to be kept over them, to conceal and make decoration possible.

When investing in shower pans, it is important to ensure that it is of good quality, as the labor cost of replacing a shower pan, by far, exceeds the cost of buying a new one. To avoid water penetration, special care must be given to the joints between the wall tiling and the shower pan. It takes anywhere between four to six hours to install or replace a shower pan. Replacement requires advanced plumbing skill and light demolition. While fixing the pipe into the drain assembly from underneath, the help of one other person may also be required.

A shower pan consists of two parts: the pan and the drain assembly. The first part of the drain is a chrome plated ring. It is threaded on the outside to allow a nut to be screwed into it from below. The nut, in turn, tightens the ring to two gaskets; a waterproof gasket on top and the metal gasket below. These are the parts of the drain assembly that direct the water from the shower into the drainpipe, preventing leaks. The final part of the drain is the strainer. The strainer is a mesh or metal screen that prevents large objects from falling into and clogging the drainpipe. The strainer is the last part to be installed. Once the shower pan is completely installed, the strainer is the only part that shows.

In new shower enclosures, quite often, the floor of the shower is made of ceramic tile, sometimes even grout. Though, a traditional shower pan is not needed in such cases, leaks must be regularly checked for I such shower enclosures. People often think that a ceramic tile floor will not retain water, that it will naturally slope towards the drain and shed all the water. It is however, possible that a substantial amount of water seeps through the tile and grout into the mortar layer. If the leak is big, it can lead to mildew and other problems. An alternative in such situations would be to use a shower liner or another impenetrable layer under the tile to serve the same purpose that a shower pan would.