Gel coat. The next day’s work begins with more sanding (Figure 10).

Figure 10. After the base coat has dried, sandpaper is used to knock down edges and rough up the whole surface to improve bonding with the finish coat (left). Brooms and leaf blowers are used to remove excess particles from the surface before applying the gel coat finish (right). Using a 36-grit sanding disc on a grinder, all of the frayed seams at the drip edges are sanded back to true the edges; the rest of the surface is sanded to remove any lumps and to rough up the base for good bonding. In final preparation for application of the gel coat, dust and residue from the sanding are cleaned off the deck using brooms and gas-powered leaf blowers. The gel coat Rick and Dan use is formulated for exterior applications and contains UV inhibitors as well as additives to increase abrasion resistance (Figure 11).

Figure 11. Tinted gel coat is applied first at edges and penetrations (top left), then on the main deck (top right), using short-nap paint rollers. The final product cures in about 30 hours and looks much like the surface of a fiberglass tub (bottom). It is also available in several colors; on this job, we used beige for the decks and white for the continuous rail capping the 3-foot tall bulkhead walls that were used instead of posts (Figure 12).

Figure 12. On this job, the wood railings were also flashed with fiberglass mat (left), then finished with white gel coat to contrast with the deck color (right). Once the resin is mixed with hardener, application begins at the edges and proceeds to the field. As with the base coat, the gel coat is applied using throwaway paint rollers. The finished product looks similar to the surface of a fiberglass tub, except slightly rougher, because it picks up the texture of the glass mat below, and also because of the nonskid surface provided by the sand. We allow the gel coat to cure for 30 hours before we set the doors. We always work while standing on sheets of plywood placed on the deck, because at this point the gel coat is not fully cured. Even after the surface is cured, we always work off of the plywood to protect the surface. The gel coat will take a lot of abuse, but early on it’s still tender. Nothing will ruin a day faster than dropping your hammer off of a 6-foot ladder and putting a chip in the new surface.

Details & Maintenance

Siding is installed as usual, with the building paper overlapping and taped to the fiberglass where it runs up the wall. At railings, we have had problems in the past with checking of the wood posts, which allows water past the fiberglass counterflashing and into the building envelope. Now we usually wrap our posts with 1x6s, holding the boards 1/2 inch off the surface of the deck to prevent wicking of moisture. In the search for the perfect railing, we have tried a few vinyl systems. The vinyl post covers that come with some of these systems work fine. Routine maintenance of the fiberglass deck surface is the same as any fiberglass boat. The surface should be cleaned periodically with a non-abrasive cleaner, such as Spic ‘N Span, and visually inspected every year for signs of excessive wear, especially at the deck-wall junction and around the posts. We have decks out there that are 10 years old and have needed nothing more than an additional application of gel coat. Repairs are fairly easy. The affected area is removed, the edges of the fiberglass are ground back, and the plywood is reinforced to ensure a sound surface. Then the fiberglass is reapplied to make the patch. The gel coat blends almost perfectly. Eric Borden owns ESB Contracting, a remodeling company in Forked River, N.J.