Waterproof Coatings

Water Does Not Come Through the Middle of a Deck

It comes in at the edges. The junction where the walking surface meets the wall, the drain or scupper edge, the base of a railing post, a sheet metal lap, a crack that opens and closes with the sun. Almost every soft balcony we are called to look at has a sound field and a failed perimeter, and almost every recoat that failed early was a field coat rolled over a perimeter nobody addressed.

So that is where we start. We look at the joints before we look at the surface, and if the joints are the problem we say so, even when the owner was expecting to be sold a full deck coating.

Deck and Traffic Coatings

For balcony walking surfaces we apply waterproof traffic coating systems: an elastomeric or polyurethane build with an aggregate broadcast into the intermediate coat for slip resistance, then a topcoat over it. Existing coating that is delaminating comes off. Cracks and low spots get patched with a compatible filler rather than being buried under extra material, because a coating follows the shape it is put on and a puddle that sat there before will sit there again.

Perimeter detail is the part that earns the money. Sealant at the deck to wall junction is cut out rather than caulked over, backer rod is set to the right depth so the bead can move, and a fresh polyurethane sealant is tooled in. Post bases get the same treatment. Old, hard, cracked sealant is a wear item that has reached the end of its life, not a defect in the original build, and it needs replacing every several years on an exposed elevation here.

Stucco Walls, Parapets and the Breathability Question

Santa Monica has a lot of stucco: Spanish Colonial Revival houses, Ocean Park and Sunset Park bungalows, and the flat faced apartment blocks that went up between the 1950s and the 1970s. Hairline cracking in stucco is normal and an elastomeric coating will bridge it. That is the correct answer on some walls and the wrong answer on others.

An elastomeric film is thick and it slows drying in both directions. On a wall that gets wet from behind, from a leaking window head, a failed deck edge above, or rising damp at a slab, sealing the outside face traps that moisture in the wall assembly and the coating eventually blisters off in patches while the stucco stays wet. So the decision gets made per elevation. Bridge the cracks where the wall is dry and the cracking is surface movement. Use a breathable masonry system where the wall needs to dry outward. Find and fix the source first where there is one.

Rust Staining and the Wall Below a Railing

Brown streaks running down a stucco face nearly always trace back to metal above: a post base, a lintel, a bracket, a fixing. Cleaning and repainting the wall without treating that metal gets you a matching stain by the following spring. We deal with the source, let it dry, then clean, prime the stained area with a stain blocking primer so the iron oxide does not bleed through, and repaint the affected elevation to a sensible break line rather than leaving a patch.

Occupied Buildings and Tight Streets

Most of this work happens on lived in buildings, on narrow lots with permit parking. We plan staging and containment before day one, keep the deck usable where we can phase the work, and give residents honest notice of when their balcony is out of use. Coatings need real cure time before traffic, which is longer than the dry time on the label, and rushing that is how a brand new deck picks up permanent scuffs and heel marks.

Call (424) 587-8615 for a walkthrough and a written scope.