Pressure Washing and Prep

The Part of the Job That Decides the Other Part

Preparation is most of an exterior repaint by hours and most of it by cost, and on a house near the harbour it is the difference between a coating that lasts eight years and one that starts letting go at three. Everything on this page happens before a drop of finish paint is opened.

The reason it matters more here than inland is simple. Salt. It arrives on the wind off the water, dissolves in the overnight damp from the marine layer, soaks into the top of the stucco and dries into the surface. It is invisible on a light coloured wall. It is hygroscopic, so it keeps pulling moisture out of the air and holding it right at the point where you want paint to bond. A coating applied over a salt film is being asked to stick to something that is permanently slightly wet.

Washing, and Why Pressure Is the Wrong Word

Most coastal prep is a rinse, not a blast. On stucco we work at low pressure with a wide fan and plenty of clean water, moving from the top of the elevation down, and we keep going after the wall looks clean because the point is to dissolve and carry away salt rather than to remove dirt. A quick pass with a high pressure tip does the opposite of what is wanted: it drives water into the wall, chews out soft stucco around cracks, and leaves wand marks that show through a satin finish for the life of the coat.

Higher pressure has its place on sound concrete, on a driveway, or on a stripped section where we are removing failing coating deliberately. On old wood siding it is close to vandalism. Water forced up behind a lap board takes weeks to dry and comes back as a blister in the new paint.

Mildew is the other thing that comes off at this stage. On a north facing wall under an overhang, in a city with damp mornings, mildew is normal rather than a sign of neglect. It is treated with a dilute bleach solution and rinsed, and it has to be killed rather than just washed, because painting over live mildew simply feeds it through the new film.

After washing, the wall has to dry. Genuinely dry, not surface dry. Stucco that has been soaked wants a day or two of decent weather, longer in a heavy June gloom week. Rushing this is one of the two most common reasons an exterior fails early. The other one is below.

Scraping, Sanding and Feathering

Every square inch of loose coating comes off. Not most of it. All of it, because whatever is left is now the weakest layer in the system and the new paint is only as good as what it is holding onto.

Once the loose material is off, the edges of the sound paint around each bare patch have to be sanded back so they feather into the substrate. Skip that and you get a visible ridge around every repair, which in low afternoon sun turns a repainted wall into a map of its own history. Feathering is slow, unglamorous, and it is the single clearest tell between a professional exterior and a fast one.

On any house built before 1978 this step is done lead safe: plastic sheeting down, wet sanding or a shrouded sander with a vacuum, no dry scraping into open air, and a proper clean up at the end of each day. The bungalow streets here are largely pre-war, so this is routine work rather than an exception, and it is a fair question to ask any painter who quotes your house.

Priming, and Why the Primer Is Not Generic

Primers are not interchangeable, and the wrong one is worse than none.

• Masonry and alkali resistant primer on bare or patched stucco. Fresh stucco and patching material are strongly alkaline, and a standard primer will saponify against them, meaning the film chemically breaks down and turns soft.
• Bonding primer where a wall has been chalking heavily and cannot be washed back to a clean sound surface. It grips loose pigment that a normal primer would simply sit on top of.
• Stain blocking primer on bare wood, particularly on redwood and cedar, where tannins bleed straight through a waterborne finish and show as brown streaks a few weeks later.
• Rust inhibitive metal primer on railings, screens and any ferrous fixing, back to sound metal first.

Spot priming is normal. A wall that is largely sound does not need priming end to end. What it does need is every bare patch primed properly, and every patch primed with the right product for that patch.

Caulking and the Small Holes

Caulk goes in after priming, not before, so it bonds to primer rather than to dust. We work the joints where two different materials meet: trim to stucco, window frame to wall, corner boards, the top of a sill. A good exterior sealant stays flexible for years and moves with the joint. The cheap acrylic tubes go hard and split within a season, and then the joint is worse off than if it had been left open.

Nail holes and small gouges get filled and sanded flush. Larger stucco cracks get cut out, patched and cured before anything else happens to them.

Masking, Containment and Living in the House

Almost every job we do is an occupied home. Windows, light fixtures, meters, plants and the neighbour’s car all get covered. Drop cloths go down and come up daily rather than sitting out for a fortnight. Where we are sanding, containment goes up. At the end of each day the site gets swept and the driveway gets cleared, because a two week exterior job should not mean two weeks of not being able to use your own path.

Call (562) 235-8413 to talk through what your walls actually need, or find us at 2573 Clark Ave, Long Beach, CA 90806.