Re-coring a rotted deck plate
Let’s begin with the fact that nearly all boat decks are cored with materials like balsa, plywood and foam. The coring is necessary for several reasons, including strength. But the cores are also good heat insulators too, and there’s nothing wrong with the basic concept of coring a deck except when water gets into it. Leaking decks usually have two basic causes:
1. Improper design, construction and installation of hardware.
2. Installation or removal of hardware and other equipment by the owner.
The first thing we need to understand about decks is that the cores must be designed to be completely water proof, followed by the rule that nothing must ever be done to the deck to damage that water proofing. Of course, people find it necessary to attach things to their decks, and that’s where the second basic problem arises. They drill holes in the deck and screw things down without realizing that what they are doing is creating a point of water entry into the core.