Home’s Outside Wall Material Has Little Effect on Moisture

Question: We will build a new home on our lot in Cambria, Calif., about a mile from the ocean near the Hearst Castle. Should we use wood siding on the house, stucco or a kind of texture stucco that I understand will not hold moisture or cause moss and mildew to grow in the house and closets?

Answer: You’re talking about apples and oranges here: the choice of an exterior wall covering--siding or stucco--should be governed by aesthetic considerations, not moisture ones.

Make sure that the architect specifies a first-quality vapor barrier to prevent moisture problems. This is easier said than done; even the architects aren’t sure about proper vapor barriers. Vinyl vapor barriers are often recommended, but they are difficult to apply properly; one or two holes in the vinyl can defeat the purpose of the barrier.

Paul Bozarth, 557 Sturgeon Drive, Costa Mesa 92626, an architect who designs homes and remodeling projects in coastal Orange County, suggests the use of felt paper as a vapor barrier under wood siding and a similar product under stucco. Wood siding has an edge--because of its porosity--over stucco if there is a concern about moisture and mildew, but it requires more maintenance than stucco, he said. Make sure that proper ventilation is provided, in the form of roof and/or gable-end vents or attic fans. Bathroom ventilation is especially important and you might consider special exhaust fans for the bathrooms.

Manufacturers’ representative Jack Janofsky, 148 S. Crescent Heights Blvd., Los Angeles 90048, handles a line of “liquid foil” vapor barrier coatings that might be ideal for a high-moisture area like Cambria. You might have your architect and/or contractor get in touch with Janofsky or another supplier of a liquid vapor barrier.

Dale Baldwin will answer remodeling questions of general interest on this page. Send your questions to Home Improvement, Real Estate Department, Los Angeles Times, Times Mirror Square, Los Angeles 90053. Baldwin cannot answer questions individually. Snapshots of successful do-it-yourself projects may be submitted but cannot be returned.