What a Deck & Balcony Waterproofing Job Involves, From Inspection to Closed Permit

The sequence, start to finish

Step 1: the inspection, and why the test section matters

A deck cannot be quoted from the surface. The free inspection checks the places decks leak, the door threshold, the wall, the posts, the low corner, the ledger and the scupper, and the ceiling below for stains, then opens a small test section of the old coating where the signs point. Firm, dry plywood with intact flashing means a re-coat may be enough; soft or wet plywood, or flashing that was never installed, means the deck comes down to the sheathing. The re-coat, tile or rebuild guide goes through that decision.

Step 2: the scope and the fixed price

The proposal lists what comes off, what is repaired, what is flashed, which system goes on and which permit and inspections are included, line by line. That is the document the price is attached to and the document the final invoice is checked against. A scope that says "waterproof deck" and a number is not a scope. Ask for the manufacturer and the ICC-ES report number of the system, and for the flashing to be named at each transition.

Step 3: the permit

Inside the City of Los Angeles, replacing a deck or balcony waterproofing system is permitted work through LADBS, and the plywood, joist, ledger or railing repairs found under the old coating are inspected under the same permit; hillside parcels add the Baseline Hillside Ordinance review. Burbank, Glendale, Beverly Hills, Pasadena, Santa Monica, Culver City and West Hollywood issue their own. The permit is pulled in the owner's name by the contractor, and the closed permit at the end is the record a buyer, an insurer or an SB 721 / SB 326 file will ask for.

Steps 4 and 5: tear-off, and what it finds

The failed coating, tile or magnesite comes off to the sheathing. This is the only moment anyone sees the plywood and the framing, so it is photographed, and the photos go to the owner. Soft sheathing is replaced; a joist or a ledger section that has rotted is sistered or replaced; a post base that has gone is rebuilt. On most decks that have leaked for a while there is some of this, and it is why the inspection opened a test section: so the scope already includes what the test section showed, and only genuinely hidden conditions are priced as a written change before the crew continues.

Steps 6 and 7: slope and flashing, the layers that keep the deck dry

Water that sits finds a seam; water that leaves does not. The deck is corrected to drain to its scupper or drain, with no low corner. Then every transition gets metal: the door sill flashed and the membrane turned up behind it, the stucco wall counter-flashed so water behind the stucco cannot get behind the membrane, each railing post flashed or sleeved rather than caulked, a drip edge that reaches past the fascia, and the scupper tied into the membrane. These two steps are where most failed decks were never done right the first time, and they happen before the system goes on.

Step 8: the system

Pedestrian traffic coating systems for decks over plywood or concrete carry an ICC-ES evaluation report that states the layers, the substrate conditions and, for most, a Class A roof-covering classification. The system is installed in the order and at the coverage the manufacturer specifies: primer, base membrane, reinforcement where specified, intermediate coats, and a slip-resistant wear coat, with the cure time between coats respected. Rushing cure time or thinning coats to save a day is invisible on the day and visible in two winters.

Steps 9 and 10: inspections, walkthrough, closed permit, warranty

The building inspector sees the framing before it is covered and the finished deck at the end; the contractor schedules and meets both. The walkthrough with the owner checks every threshold, edge and drain, the punch list is cleared, the permit is closed, and the written workmanship warranty is handed over with the manufacturer's product warranty registered where the manufacturer offers it. Final payment follows the walkthrough, not the last coat.

Questions that tell you whether a contractor works this way

• Will you open a test section before pricing, or quote from the surface?
• Which system, and what is its ICC-ES report number?
• Where exactly will you flash, and how will the stucco wall be counter-flashed?
• Who pulls the permit, and will it be closed before the final payment?
• What happens if you find rot the scope did not include?
• Is the workmanship warranty in writing, and for how long?
• May I verify your license at cslb.ca.gov and see the insurance certificates?

A contractor who answers all seven without hesitation is doing it in this order. Right Image Builders does, across Los Angeles and 27 cities, with its own crew, one permit and one contract.

Sources (checked October 2026): ICC-ES evaluation reports for pedestrian traffic coating systems over plywood and concrete (for example ESR-2201 Westcoat ALX, ESR-2097 Pli-Dek, ESR-1757 Dex-O-Tex Weatherwear), including Class A roof-covering classification and installation conditions; Los Angeles Department of Building and Safety, plan check and permit information; Health and Safety Code §17973 (SB 721, as amended by AB 2579): exterior elevated element inspections for buildings with three or more multifamily dwelling units; first inspection by January 1, 2026, then every six years; non-emergency repairs within 120 days of the report; Civil Code §5551 (SB 326): inspections of load-bearing exterior elevated elements and associated waterproofing in condominium associations with three or more units; first inspection by January 1, 2025, then every nine years, by a licensed structural engineer or architect; Right Image Builders service and neighborhood pages (2026 planning ranges, timelines, permit authorities). Cost figures are Right Image Builders' 2026 planning ranges from its service and neighborhood pages.