BACKGROUND

Shower drains can be time consuming to install and if not done properly can result in leaks that can damage the floor and ceiling beneath it.

In a typical shower stall having single point drainage, the shower drain comprises three primary components: a primary drain body that couples to the drain pipe and includes a raised lower flange; a locking flange that sandwiches a membrane between it and the lower flange body; and a height adjustable drain cover assembly.

In a typical installation, the body is installed first and connected to the drain pipe through a hole in the subfloor. The drain body is secured to the subfloor wherein the top surface of the lower flange typically rests above the subfloor a predetermined distance to accommodate the thickness of the shower pan. Next, the shower pan is installed which can comprise a plurality of pre-sloped panels that terminate at the edges of the lower flange and are generally flush with it. If the panels or dry set pan is not waterproof, a membrane may be bonded to the pan as well as over the drain's lower flange. If the pan is waterproof a section of membrane can be placed over the drain that overlaps the pan. The membrane is then sandwiched between the lower flange and the locking flange. Finally, a height adjustable drain cover is threadably installed at a cover surface height above the locking flange that takes into account the thickness of the finish flooring, such that the drain cover will rest flush or slightly lower than the surface of the surrounding finish flooring when the stall is complete.

As can be appreciated, if the membrane is not properly secured between the lower flange and the locking flange, such as might be caused by a fold or crease in the material a potentially costly leak can result. Further, just the act of trimming the membrane around the opening including cutting holes for a plurality of affixing fasteners can add a substantial amount of time to the installation process.

In other instances, and installer may want to use a different drain cover assembly than is supplied with the lower pieces. However, this is often not possible. Even though the threading in the drain body or locking flange can be similar between drains of similar size among different manufacturers, in practice the actual sizes, because of differing manufacturing tolerances and standards, may be sufficiently different to prevent the drain cover from one manufacturer being used with the threaded locking flange or body of another manufacturer.

