Landscape lighting systems contain metals that react with salts and moisture. The corrosive nature and extent of these reactions depends on the type of metal, any protective coatings and the duration and frequency of wet contact.
Emphasizing the corrosive strength of sea spray, a study showed that the corrosion rate of metal 80 feet from the shore is 10 times that of the same metal at 800 feet. All types of corrosion are accelerated - pitting, rusting, stres cracking, and loss of protective coatings (including powder coat). In deciding the materials to use in seaside landscape lighting projects, corrosion resistance is paramount.
Keeping this list in mind, we can look at each system component in turn, idenifying the types of materials and construction that will best suit seaside projects.
- Multi-tap Transformers
The heart of the transformer is its core For best protection against moisture, select a transformer with a resin-sealed (potted) core. Also select one that has a stainless steel enclosure.
Many contractors use stranded copper wire for lighting jobs. A better choice for oceanside projects (and all projects, for that matter) is to select tin-coated marine-grade wire - it costs a few dollars more, but is well worth the money for the extra corrosion resistance.
- Splice Points
Wire splices are the most vulnerable part of a lighting system, its best to reduce the number of splices by using pre-wired fixtures and the CAST Spider Splice method of installation. in addition, for maximum protection, splice points should be soldered and sealed in silicone-filled wire nuts.
In wet environments; lamp sockets can be periodically coated with lithium grease to prevent corrosion of the contacts. Also, better fixtures will have crimped and soldered internal connections to the sockets for the most corrosion-resistant construction.
In selecting fixtures for seaside projects, choose for corrosion resistance and durability; solid bronze is the ideal metal on both counts. It's more corrosion resistant than copper and brass and can withstand the physical abuse of storms. Natural bronze also quickly turns a natural patina due to the salts in the sea spray, and its appearance continues to improve with age.
More Material Considerations
To protect against storm damage, all fixtures should have unbreakable (preferably solid bronzze) stakes or be securely mounted with stainless steel screws. Also, since some landscape surfaces near the sea are subject to change due to wind, water, and shifted sand, an installer should leave plenty of extra wire bruied near the fixture to allow repositioning when needed. the installer may also want to keep in mind that if cold sea spray contacts an exposed lamp (bulb), it may burst. For this reason, a fixture subject to sea spray should be constructed with its lamp enclosed or shielded.
Aside from technical considerations at the shore, there is also much to be said about the lighting design. Good landscape lighting illuminates beauty that already exists in the property and enhances the nighttime experience. The most obvious (and beautiful) feature of an oceanfront property is the ocean that is already perfectly lit by the moon and stars. The designer needs to take that as a starting point and devise a lighting design on the property that extends the natural beauty of the nighttime ocean into the property. In most cases this will necessitate a subdued lighting with a natural, moonlit feel.
To accomplish this, the designer may use moonlights from trees on the property and accent these with low-wattage fixtures strategically positioned to provide safe passage and usability of decks and patios. If possible, lights should be positioned to provide a natural-looking and subdued visual pathway to the ocean.There should be no glaring lights to interfere with or distract from the ocean view. If docks or piers are present, they should be lit with glare-free lights at minimal levels for safe passage. In some cases, lights may be aimed into the water to produce both diffuse glows and dynamic (yet subtle) reflections onto pilings or piers.
To conclude, enhancing the nighttime experience in a seaside landscape can only be accomplished with the intelligent choice of low voltage lighting system components and with the esthetic sense to recognize that the beauty of the ocean is the visual backdrop for the lighting design.
*“Atmospheric Corrosion of Metals, CBD-170”, Canadian Building Digest, National Research Council Canada, 1975, website: http://irc.nrc-cnrc.gc.ca/cbd/cbd170e.html
**. The Landscape Lighting Book, by Janet Lenox Moyer, John Wiley & Sons, N.Y., 2004
Created on: 07/31/08