How to Install EVA Foam Decking (SeaDek-Style Pads) on Your Boat

Walk the boat and mark the areas to cover. Keep pads off drains, scuppers, fuel fills and vents, and cut separate pieces for hatch lids so the hatches still open and close. Plan a gap of at least 1/4 inch between pads; SeaDek says the foam expands and contracts, and the gap also lets water drain. On decks with raised nonskid surrounded by smooth gelcoat, BoatUS recommends making each pad reach at least 1/4 inch past the raised pattern onto the smooth border, because the adhesive grips smooth gelcoat far better than textured nonskid.

BoatUS uses clear Mylar sheeting. Cut it at least half an inch bigger than the area on all sides, tape it down tight with no ripples, and trace the outline with a permanent marker, using a straightedge for straight lines. Make separate templates for hatches and around obstacles. Write "top" and the location on each one.

If the decking came on a roll, unroll it and let it lie flat for several hours before cutting. BoatUS notes it relaxes faster on a clean, warm surface in the sun.

Lay the material on plywood, tape its edges down, then tape the template on top. Cut along the lines with a sharp knife, using the straightedge on straight runs. Change blades as soon as they drag; a dull blade tears the foam. Round any sharp corners slightly; they are less likely to catch and peel.

SeaDek says to install only between 50 and 100°F. Cold adhesive does not grab well, and very hot weather makes the foam soft and stretchy. Work on a dry day with the deck dry to the touch.

Boating Magazine pried up each old pad's edge with a plastic putty knife and pulled slowly, without gripping so hard that the foam tore. SeaDek suggests a little acetone under a pad that tears instead of lifting. The leftover adhesive is the slowest part: Boating Magazine wiped on mineral spirits, let it soak a few minutes, scraped carefully, and repeated three times before wiping with acetone. Work outdoors with eye protection, gloves and a respirator, and use a plastic or gentle scraper so you do not gouge the gelcoat.

Prep decides how long the pads stay down. SeaDek's current instructions: scrub with Dawn dish soap and a clean, lint-free rag to remove grease, adhesive, wax, mold release and dirt, then wipe with 99 percent isopropyl alcohol on a fresh rag. BoatUS adds that some makers want an ammonia-based cleaner first, and that acetone or alcohol is the final wipe; follow your decking maker. Brand-new boats can carry mold release that takes more than one pass. Let the surface dry completely.

Before peeling any backing, lay all the pads in place and check the fit and the gaps. SeaDek is clear that once you start sticking a pad down you cannot adjust it, and BoatUS warns the adhesive is aggressive and fast. Fix any fit problems now.

Flip the first pad over. With a sharp knife, cut only through the paper backing (not the foam) from the center out toward the edges. Peel back a couple of inches on each side of the cut and crease it so it stays folded. Flip the pad back and set it exactly in position.

Tape one half of the pad to the deck with masking tape so it cannot move. Lift the free half, peel the backing back, and lower it onto the deck, pressing from the center outward so no air is trapped. SeaDek has you peel and press a few inches at a time. Then remove the tape, lift the other half, peel, and press the same way. Do not pull, stretch or squeeze the foam while you lay it, or it will distort.

When the pad is down, press firmly over the entire surface; BoatUS stresses the edges, where lifting starts. A small hand roller helps. Boating Magazine simply walked over the new pads. BoatUS says the decking can usually be walked on in about an hour, but check your maker's instructions for any cure time.

SeaDek recommends its own foam cleaner, or dish soap, an all-purpose cleaner or degreaser in warm water with a medium-bristle brush, then a rinse. For stubborn stains it suggests a diluted bleach solution scrubbed gently with a soft brush and rinsed well, and vinegar or oxalic acid for rust spots, kept away from pad edges where it can attack the adhesive. A light-duty, low-pressure washer with a wide tip is OK if you keep your distance. SeaDek lists several common boat soaps and protectants to avoid, so check its list before using a product. Clean spills, fish blood and sunscreen soon, before they set.

BoatUS describes a rare problem called sunburn: a shiny metal fitting or white gelcoat surface at just the right angle can focus sunlight onto the foam and melt a spot. It usually is not covered by warranty, and the fix is to change how the boat sits relative to the sun or shade the area. Check edges every few trips. BoatUS found that pads with poor prep, or ones that do not reach smooth gelcoat, start to lift after about three years and need resticking with spray adhesive, while well-installed pads were still solid in their fifth season.