Could timbers with wooden spikes be used instead of galvanized steel when repairing the wood cribs that support a boathouse? Would wooden spikes shrink and swell with the rest of the wood, leaving less space for rot?
You’re better off using galvanized steel. In the past, dock and ship timbers were fastened with hardwood spikes, more commonly called treenails (pronounced “trunnels”), but that was because the only available alternative – iron – rotted out quickly. Galvanized steel corrodes over time too, but much more slowly.
The advantages of galvanized steel are its shear strength and ability to withstand lateral pressure, which is exerted by waves, currents, and ice. Since treenails have less shear strength, cribs will probably last longer with galvanized steel. Another fastening option is stainless steel.