Yes, you can replace wood boards with composite, though there are a few factors to take into consideration. First, you will want to make sure your substructure is code-compliant and can hold the extra weight of a TimberTech composite board. Confirm that the thickness of the new TimberTech board is the same as the wooden board it replaces to ensure your deck remains smooth and flat. You can find the thickness of our products on their individual product pages.
Although replacing old wood deck boards with TimberTech boards can be done, it can result in an undesirable patchwork appearance. A better option, if your substructure is code-compliant, would be to replace your entire deck with all TimberTech deck boards.