Here on the Central Coast of California many are blessed with the opportunity to build homes in close proximity to Monterey Bay. Whether contemplating constructing a new home or building alterations or additions to an existing home, those nearest the shore would do well to consider a few of the basic tenets for constructing in the nearshore environment.
This zone, or microclimate, is characterized by wind-driven spray and salt-saturated fog, presenting specific challenges to the longevity of the completed building. Depending on geography, this zone can extend from several blocks to several miles inland from the shore.
This is one of the more corrosive environments to build in, attacking especially exposed exterior metals, wood, and building elements including windows, doors, and hardware. Interior items can also be affected: I’ve seen old metal parts stored in attics in advanced stages of ocean-induced corrosion.
Symptoms of ocean-induced corrosion in metal range from simple patina effects, to encrusting, to wholesale degradation of the affected item. In wood, unless carefully selected and protected, the effects generally result in accelerated aging and deterioration of the material. Subjected hardware becomes “sticky” or fails altogether: locksets fail to lock or unlock, hinges are attacked and eaten through, aluminum windows don’t slide properly. Even structural elements are susceptible to corrosion, rendering them subject to failure, and presenting very real life-safety issues.
Fortunately, there are guidelines to follow in the near-shore environment to offset these effects.
For structural metals and connectors, galvanization is often the answer. Some manufacturers also offer extra-thick galvanized coatings, especially developed for more corrosive environments. For other exposed metals, such as gutters, downspouts, and flashings, the prudent designer will generally specify copper in lieu of the ubiquitous sheet metal for these applications. Plastic products also present an attractive alternative, although even these products will suffer shortened lifespans in this environment, and their susceptibility to impact damage should be considered by the specifier.
Unprotected woods will patina from their fresh golden hues to a steel grey or even black, depending on the species. For many, this is a distressing sight; for others this is a natural phenomena to be welcomed. The darkened color of the patina signifies that the the exterior surfaces have oxidized, helping to protect the interior material. But only redwood, cedar, or the adventuresome, traditional exotics such as teak are acceptable materials in the nearshore environment.
For those who would prefer see the greatest longevity in these materials, painting is usually the answer. The designer is then careful to specify paint product regimens which will hold up well over time. Back-priming, always a good idea, becomes imperative to assuring a successful installation.
Even the fasteners used for laying up the siding need careful consideration in this environment. Ordinary galvanized nails, adequate for most applications, may not hold up, or may leave unsightly plumes of stain on the surface of the finish wood. Better options begin with stainless steel fasteners, and progress to more exotic metals such as copper, although copper is not suitable for some woods including cedar.
As suggested earlier, aluminum windows are a definite non-starter in this environment. Wood, pultruded fiberglass, or vinyl windows are the acceptable options, although the latter two have a relatively short life-cycle experience behind them: only time will tell how these newer product lines will hold up.
Even for wood windows, the serviceability of the unit will be a direct result of the finish option specified: vinyl cladding or factory-installed and warrantied coatings such as kynar will offer the greatest longevity. Hardware, such as hinges and latches, should be specified for maximum corrosion resistance, lest they too be subjected to briny degradation.
Building in the nearshore environment demands that the designer devote greater attention to detail and a higher caliber of specification writing if the end product is to hold up well over time. This is one instance where a little extra “T.L.C.” today will pay dividends in the years to come.