A shower trench drain apparatus includes a shower trench drain body of polymeric material having an integrally-formed drain channel with angled bottom surface and drain opening or openings, a waterproof membrane over the drain body, a clamp ring retaining the membrane to the drain body, and a grate adjustably retained to the drain body by a height adjustment mechanism. The trench drain body formed from a block of material such as PVC or ABS, which are compatible with approved plumbing materials and codes. The block has a flat bottom adapted for horizontal support during installation and includes integrally-formed features facilitating adjustment during installation while minimizing components and separate parts and simplicity of installation.