Coastal lighting - things to remember
Author: Glenn Harper
Published: March 7, 2013
Regardless of where you are in Great Britain, you’re never really more than about 70 miles from the sea. The coast plays some part in most of our lives, even if it’s only a place where we occasionally go to relax with family or friends. It’d be a rare British photo album that was bereft of any seaside snaps!
If you are running or opening a business near the sea - perhaps one that caters specifically for the holidaymaker like a B&B or seafront hotel - effective exterior lighting helps create that all-important first impression. But as we’re about to discover, coastal locations present particular challenges for specifiers, designers, or end-users when it comes to choosing suitable materials and products.
Various influencing factors dictate the amount of airborne salt that a coastal property is subjected to. These include topographical features such as beaches and cliffs, land and water temperature differences, wind speeds and direction, sea and surf turbulence, and land projections into the sea. Coastal salt is hygroscopic - it attracts water, thus it easily creates a highly corrosive electrolyte solution that acts as a catalyst to oxidation and rust. This only gets worse as the seasons warm up and humidity rises.
A building that is close to sea water is patently exposed to more salt than one that is several miles inland, whether it’s by direct spray or splashing, although this may be mitigated by a sheltered or calmer location such as a harbour or estuary. Regardless, if you’re within a few miles of the sea you’ll save yourself needless hassle and expense by investing in the right kind of light fitting from the outset.
Material gains - misconceptions and making the right choice
When choosing exterior lights for a coastal property you’d be forgiven for thinking that stainless steel may be a good choice of material. After all, under ordinary circumstances it lives up to its name by not staining or corroding easily. However, stainless steel is manufactured to a variety of tolerances and is graded accordingly; the type of stainless steel you’ll typically find in lighting products is no match for airborne sodium chloride and its high-speed corrosive effects.
Installing standard-grade stainless steel at a coastal location will result in staining and corrosion within a short space of time; even regular marine-grade stainless steel can sometimes be susceptible to corrosion in harsh environments. In any case, marine-grade stainless steels such as types 316 or the more resilient 2205 are prohibitively expensive for the purposes of lighting manufacture, so aren’t typically used.
Brass is another popular choice for outdoor lighting under normal circumstances, but in coastal areas it becomes vulnerable to corrosion by the same path as stainless steel - a process that is accelerated in either of those metals when temperature and humidity levels rise above an optimum salt activation level (10°C and 76% humidity in the case of sodium chloride, which is the predominant chloride in coastal salt). Most types of brass are prone to a process called ‘dezincification’, which increases vulnerability towards corrosion, and excludes it as a suitable and affordable material for coastal lighting products.
Light-fitting materials particularly suitable for coastal areas are:
- Bronze, a copper alloy that oxidizes very superficially to produce a protective layer—the attractive verdigris patina that is often seen in outdoor bronze statues. Be sure to double-check for coastal suitability, as ‘bronze-finish’ lights are unlikely to be resistant to salt corrosion.
- Galvanised steel is coated with a zinc oxide and once exposed produces a protective compound called zinc carbonate, which retards corrosion. Note that products manufactured in galvanised steel are likely to be irregular in texture and finish, which is often considered an inherent part of each item’s unique appeal.
- Copper can be pre-treated to preserve its polished finish or left to its own natural devices to form a weather-resistant patina (copper carbonate). Again, the more natural look is sometimes preferred.
- Polycarbonates are often used in no-nonsense exterior lighting designs, and are an ideal choice for coastal applications where function takes precedence over decorative appearance. Construction is usually extremely tough - resistant to vandalisation as well as the elements.
Maintenance of coastal lights
Whilst polycarbonate products are intrinsically low maintenance, copper and galvanised steel used in a corrosive coastal environment can benefit from a regular dousing with fresh water. General cleaning of a galvanised surface can be carried out with laundry or car wash soaps, taking great care to thoroughly rinse afterwards. Avoid any type of abrasive or mechanical cleaning that is likely to breach the zinc patina of the product, as resulting damage means the coating has to then repair itself, and by digging into its reserve of zinc this reduces the effective lifespan of the fitting. Try to rinse your exterior lights around once a month.
Tried & Tested Bestsellers
To supplement this guide to coastal lighting, please allow us to point you towards a selection of high quality products that are resilient to corrosive sea air!
In terms of galvanised steel lights you might like the Vejers Standard Wall Lamp, Luxembourg Wall Light, or perhaps the Stockholm Exterior Post Light for garden or paving areas. You’ll note that many of our exterior lights are Scandinavian in origin, the Scandinavians being vastly experienced in lighting design for harsh environments!
We also offer handsome copper lights suitable for coastal locations such as the Blokhus Wall Light and complementary Blokhus Post Light. These lights come with a 15-year anti-corrosion guarantee, and as you’d expect offer complete weather-proofing, as evidenced by the IP54 Ingress Protection rating.
Finally, if you’re running a business near the sea that needs practical, anti-corrosive lighting with a less decorative and more functional leaning, take a look at tough polycarbonate products such as the neat Marine PIR Wall Lantern from Massive, or the no-nonsense Horizon Bulkheads with an extremely water resistant IP rating of 65.
Lyco has an extensive range of coastal resistant lights, so whether you run a restaurant or B&B, a hotel or residential home, or any other form of business that happens to be within 10 miles of the sea, you can be sure we have your needs covered!
For more advice, inspiration and news take a look at our Lighting Advice section.