Power Washing a House Before Painting in Temecula
On stucco that has never been sealed, a pressure wand set too high does more harm than the dirt it removes. For exterior painting in Temecula, CA, the running record exterior painting temecula ncw india holds on prep work starts with washing, because paint only grips a surface that is clean, sound and dry.
What the wash is meant to remove
Washing takes off dust, spider webs, pollen, chalk and any loose, flaking paint. Valley wind drives a fine layer of dirt onto every wall, and it packs into the texture of stucco and the grain of wood. That film acts like a release agent, so a topcoat laid over it lifts in a season. Washing is cleaning, not stripping, and a wall that still has sound paint should keep it.
Pressure settings by surface
Stucco takes a wide fan tip and a low pressure, held a couple of feet back and moved steadily. A narrow tip held close cuts into the sand finish and leaves pits that no primer hides. Wood fascia and siding need even less, because high pressure raises the grain and drives water behind the boards. A soft wash with a mild cleaner and a rinse often does the job on trim, and a pump sprayer with a house wash solution handles mildew near shaded corners.
Water in places it should not go
Water forced up under lap siding, into weep screeds at the base of the wall, or into window frames and light fixtures causes trouble later. Spray downward at the eaves, never upward into vents. Cover outlets and exterior lights, and close the windows. A wall that gets soaked behind the surface will hold moisture for days and can blister the paint that goes over it.
Wind and dust control
Santa Ana wind days are a bad time to wash and a worse time to paint, since dust lands on wet walls and sticks. Work early in the day when the air is calm, wash the upper walls first, and let the rinse run down. Sweep or hose the ground and patio afterward so fresh grit does not blow back up onto the surface while the walls dry. Plants near the foundation get a rinse as well, since cleaning runoff is not kind to them.
How long the walls need to dry
Stucco is porous and holds water for much longer than it looks. In warm, dry Temecula weather it usually needs a full day, and in cooler months near Temecula Creek it can need two or three. A damp wall under a topcoat traps moisture and bubbles the finish. Press a hand to the surface in the morning and check shaded corners and the base of the wall, where it dries last.