Copper-based wood preservatives are hard on plain steel. Pick the wrong screw and the deck looks fine for two seasons and then starts bleeding rust streaks down the posts.
The three tiers
Hot-dip galvanized is the baseline for treated lumber. Polymer-coated screws add a barrier and come color-matched to decking. Stainless is the top tier — worth it near water, on cedar, and anywhere a rust streak would be unacceptable.
Do not mix metals
An aluminum flashing against copper-treated lumber will corrode. Keep connectors, fasteners, and flashings in compatible material families, and isolate them with a barrier where the plan forces a mix.
Talk it through with us
Bring your plans, sketches, or photos to any of our four Central Michigan yards. We will walk the options with you, pull real samples, and put together a material list you can build from. Estimating is free for any project.
