How Thick Should the Flooring Be on a Fish & Ski Boat

Three-quarter-inch plywood is a deck standard, but there are options.

Three-Quarters, Marine Grade

Most plywood-floored boats come from the manufacturer with decks made from 3/4-inch, marine-grade plywood. Marine grade doesn't mean it's waterproof, just that waterproof glue was used to adhere the plies together and there are no voids in the interior plies of wood.

Try Pressure Treated

Depending on how far apart the floor supports are positioned, you could get by with thinner plywood, perhaps as thin as 1/2-inch. Try using pressure-treated plywood instead of marine grade. The price is nearly the same, but the treated wood is much more resistant to rot from being outdoors or getting wet regularly.

Bottom Line

For strength, go with 3/4-inch plywood, which is the industry standard. If price is a factor, consider thinner, less-expensive wood. In either case, consider pressure-treated plywood instead of marine grade for floor longevity.

References

• Overton's: Greenwood PlyDek XL Plywood Panels

Resources

• Share a Project: Replacing a Boat Floor