Deck and balcony waterproofing in Long Beach, CA

A deck over a bedroom or a balcony on a condo is a small flat roof that people walk on, put furniture on and wash down. Most of the leaks we trace on these decks do not start in the middle of the surface. They start where the deck meets the wall, at the door threshold, around railing posts and at the edge where water should drip clear of the stucco but does not.

Our crews waterproof decks, balconies, exterior walkways and stair landings on Long Beach homes, condos and apartment buildings. This page covers the deck systems we install, the flashing details that stop most leaks, and what happens when we open a deck and find rotted framing.

Deck membrane systems and how each one wears

The right system depends on what you want to walk on and how much the deck flexes. Fluid-applied urethane traffic coatings are built in layers over plywood or concrete with a textured top that resists slipping. Cementitious coatings with a lath base give a harder, stucco-like surface often seen on older Southern California balconies. Vinyl deck membranes are heat-welded sheets that come in patterns and handle foot traffic well.

When you want tile or pavers, the waterproofing goes underneath, with a sloped mortar bed or pedestals and a membrane that drains to the edge. Tile on its own is not waterproof, and grout passes water straight through.

• Urethane traffic coating: textured, flexible, recoatable
• Cementitious deck coating: hard surface, common on older balconies
• Vinyl deck membrane: welded sheet, many finish patterns
• Membrane under tile or pavers: hidden layer with sloped drainage

The details that stop most deck leaks

Waterproofing the flat surface is the easy part. The work that decides whether a deck leaks is at its edges. We cut back stucco at the wall so the membrane turns up the wall behind a new flashing, rather than stopping at the stucco line. At the door, a pan flashing under the threshold carries water back out onto the deck.

Railing posts are another common leak path. Posts screwed through the deck surface let water down every screw. We prefer side-mounted or fascia-mounted railings, and where a post must go through, we set it on a raised, flashed block.

• Membrane turned up the wall under new flashing
• Pan flashing under the door threshold
• Drip edge that throws water clear of stucco below
• Flashed blocks or side mounts for railing posts
• Scuppers or drains sized to clear a heavy rain

When we find rot under the deck surface

Decks that have leaked for years often hide soft plywood and damaged joists. We probe the deck and check the ceiling below before quoting, but the full picture shows once the old surface comes off. If we find rot, we stop and show you photos, explain what needs replacing and give a price for that framing work before going on.

Rebuilt decks get new sheathing with a slight slope away from the house, built into the framing or with tapered strips. A flat deck with no slope will pond, and no membrane lasts long under standing water near a door.

When to call about deck & balcony waterproofing

Decks and balconies near the Long Beach coast

Long Beach has a lot of decks over living space: roof decks on the canal homes of Naples, balconies on the condos and apartments along Ocean Blvd and in Alamitos Beach, and second-story decks added to homes in Belmont Shore and Belmont Heights to catch an ocean view. Salt air near the water corrodes railing fasteners and metal flashings faster, so we use corrosion-resistant metals on coastal decks.

Many balconies here look fine all summer and then leak in the first heavy winter storm. On condo buildings, balconies are often shared between owner and association responsibility, so we document what we find with photos for both. The City of Long Beach may require a permit for deck repair depending on the scope, especially when framing is replaced, and we check before starting.