Waterproof Coatings

Coating Is Not the Same as Painting

A paint film is decorative and mildly protective. A waterproof coating is a building component. On a Santa Monica house the places that need the second thing are the stucco walls facing the weather, the parapet caps on a flat or low slope roof, exposed decks and balconies, and the planter walls that somebody built tight against the building forty years ago.

These are also the places that get blamed on paint. A stain appearing on an interior wall after a wet week is almost never a topcoat failure. It is water arriving through a cap, a coping joint, a deck to wall transition or a crack, and then finding the path of least resistance.

Elastomeric on Stucco, and When Not To

Spanish Colonial Revival and the stucco bungalow stock here crack. Some of it is shrinkage from the original render, some is seasonal movement, and the fine map cracking that results will take in wind driven rain even though the cracks look cosmetic.

A high build elastomeric coating is genuinely good at this. It goes on far thicker than paint, it stays flexible, and it bridges hairline cracks so they stop breathing water in. Applied properly on a sound, dry wall it is the right answer and it lasts.

Applied on a wall that is already wet, it is a mistake. Elastomeric slows the wall’s ability to dry outward. If moisture is entering from a failed parapet, a leaking window head, a planter wall or rising damp at the base, the coating locks it in and you get blistering, sheets of coating lifting off, and in the worst cases damage to the render behind. This is not a rare edge case here, it is the single most common thing we walk into.

So the sequence is fixed. Moisture read first. Find and fix the water source. Only then coat. If somebody quotes elastomeric on your stucco without putting a meter on the wall, that is worth a second opinion.

Parapets, Caps and the Details That Leak

The top of a wall takes water straight down. A parapet cap with an open joint, a coping that has lost its seal, or a scupper that was caulked with the wrong product is a direct route into the wall cavity, and the damage shows up several feet away from the cause. We treat these with the appropriate sealants and coatings for a horizontal surface rather than running wall paint across them, and we detail the terminations rather than feathering them out and hoping.

Flashing at roof to wall junctions and at deck to wall transitions is the same story. Coatings are the last line, not the first. Where a metal flashing has failed, a coating over it buys a season.

Deck and Balcony Coatings

An exposed walking deck needs a system built for foot traffic, usually a reinforced base with an aggregated wearing surface and a topcoat, taken up the wall at the perimeter and properly terminated at the door threshold. Salt air and standing water find every unsealed edge. A deck coating that stops short of the wall, or that dies at a threshold with no upstand, will leak into the room below no matter how good the middle of the field looks.

Recoating a sound deck on schedule is inexpensive. Rebuilding the substrate under a deck that has been leaking for three years is not, and it is one of the few places where we will push an owner to spend now.

Interior Repair After the Fact

When water has already been inside, we deal with that too. Water marks need a stain blocking primer, not another coat of wall paint, or they ghost back through within weeks. Damaged drywall or plaster gets cut out and made good rather than skimmed over. But we fix the exterior source first, every time, because the interior repair is the visible half and the least useful half.

What a Survey Covers

We look at the walls, the caps, the decks, the window heads and the planters, we take moisture readings, and we tell you which of those is actually letting water in. Sometimes the answer is a hundred dollars of sealant and no coating at all. We would rather say that and be the people you call for the repaint.

Call (424) 320-8137 to book one.