Grey PMMA waterproofing membrane freshly applied to a covered terrace before the finished floor goes down

Residential / Balcony waterproofing

The floor underfoot is a roof for the room below.

PMMA and torch-applied modified bitumen membranes, installed beneath the finished floor on balconies, terraces, and decks — so what happens above never shows up as a stain below.

How it’s built

Liquid-applied PMMA

A two-part polymethyl methacrylate resin, reinforced with a polyester fleece, that cures to a seamless membrane in minutes rather than days — no cold joints, no weak seams, tile or pavers the same day.

Torch-applied modified bitumen

SBS-modified bitumen sheets heat-welded into one monolithic layer — the same flexible, traffic-rated system podium decks and balcony substrates are built on.

The transitions

Doors, walls, drains, and thresholds are where these systems succeed or fail — flashed and terminated so water has nowhere to go but off the edge.

In the field

PMMA waterproofing membrane at a door threshold and window wall on a terrace — PMMA membrane detailed at a door threshold and window wall

Roofer torch-applying a modified bitumen waterproofing membrane — Torch-applied modified bitumen, heat-welded seams

Other residential options: Standing-seam metal· Clay & concrete tile· Synthetic shake & slate· Low slope

Planning a balcony or terrace?

Send the plans, or a photo of the substrate. We will tell you which system fits and give you a real number.

Call (512) 263-8870 Send the details