Siding-lap-clearing

The scraping sound of a sharp putty knife against a dried cedar lap reveals how much paint has accumulated on the edges. Every teardown santa monica house painting ca sealaska timber has logged shows the same thing, where thick layers of old latex prevent the boards from seating correctly. Proper paint work in Santa Monica, CA requires clearing these overlaps to prevent moisture trapping and peeling.

The Mechanics of Lap Clearing

Excessive mil thickness at the overlap creates a wedge that pushes the bottom board away from the substrate. This build up often happens after multiple cycles of applying a semi gloss or satin finish without stripping the previous layers. Using a stiff blade to scrape the lip of each piece of siding is the first step. A flat blade works better than a rounded one for removing the stubborn buildup of an old oil based coating. The goal is to reach the original profile of the wood or fiber cement without gouging the material.

Surface Preparation and Sanding

Once the heavy ridges are removed, the edges require a smooth transition to prevent the new coating from pooling. Scuff sand the cleared edges to remove any remaining microscopic bits of dried enamel. This creates a mechanical bond for the next layer. If the siding shows signs of rot or deep cracks, patching with a high quality filler is required before any liquid is applied. A clean surface ensures that the new coating sits flat against the board rather than bridging the gap between the lap and the face.

Applying the Foundation

A high quality primer must be applied to the cleared edges and the face of the board. This prevents the thirsty cedar from sucking the moisture out of the topcoat too quickly. Using a brush to cut in around the laps allows for deep penetration into the cleared groove. If a sprayer is used, the pressure must be adjusted to avoid heavy buildup in the overlap area. Too much material in the lap leads to the same problem that necessitated the clearing in the first place.

Finishing and Sheen Selection

Applying two coats of a durable acrylic coating provides the necessary protection against the coastal air in Santa Monica, CA. The choice of sheen affects how well the edges appear seamless. While a flat finish hides imperfections, a satin or semi gloss makes the laps more visible if the clearing was not done correctly. Ensuring even coverage across the laps prevents water from sitting in the grooves. Once the coating cures, the transition between boards should be nearly invisible to the eye.