To fix a leaking shower drain, the old drain assembly should be removed to determine the cause of the leak so that any damaged parts can be replaced. A shower drain is comprised of multiple parts designed to fit together and form a watertight seal. If the leak is in the shower drain assembly, these parts can be replaced by a handyman or homeowner with a moderate skill level, and are usually available for purchase at local home improvement stores.
A leaking shower drain is often first noticed as water damage on the ceiling or wall in the room below it. To diagnose the problem, the shower drain must first be disassembled to discover which part is malfunctioning. It may also be necessary to access the crawl space between the floor and ceiling directly below the shower drain to determine the extent of the water damage.
The primary parts used in a shower drain assembly are the strainer, strainer body, shower pan, rubber gasket, drain body, and drain pipe. The drain pipe should be permanently attached to the connecting water lines of the house and is typically made of PVC. If the drain pipe is leaking, it must be unattached from both the water supply lines and the shower drain assembly. This type of repair usually requires the expertise of a professional plumber.
The strainer is the visible portion of the drain, often made of metal, which prevents large objects from going down the drain. This can be removed by unscrewing the two screws which hold it into place. Once the strainer has been removed, the full drain assembly should be visible, and the source of the leaking shower drain identified.
The strainer body and drain body are usually connected by interlocking threads and plumber's putty. Between these two pieces lies a rubber gasket, which rests against the surrounding shower pan. This gasket prevents water from seeping through the strainer body and drain body and into the surrounding wood and drywall of the house. The strainer body can be removed using channel locks to further diagnose and repair the leaking shower drain.
Any old plumber's putty used to install the original drain assembly should be examined and removed with a fine wire brush. As this putty ages, it tends to become brittle and cracked. If this is the source of the leak, and none of the drain assembly parts are damaged, then new putty can be spread into place to create a water tight seal.
The rubber gasket which rests between the drain body and the shower pan can be removed by gently nudging the drain pipe to the side until the gasket is slightly visible. It can be lifted away by hand and examined for damage. Old gaskets, like old plumber's putty, can crack with time until they no longer form a water tight seal around the shower pan. A new gasket can be put in place by sliding it between the drain body and shower pan. New plumber's putty should be used with this type of repair, and spread generously around the strainer body to ensure a water tight fit.
A cracked or damaged strainer body can be replaced with a new one by purchasing an identical or similar match at a local hardware store, or through online ordering. When the strainer body is cracked, it can allow water to seep into the shower pan or between the gasket and drain body, creating the leaking shower drain. The new strainer body should be matched to the threads of the old body exactly, to ensure that the new part will fit with the existing drain body. If the threads are not exact, these two parts will not screw into one another, and will not be able to form a watertight seal.