Replacing a Large Deck with Pavers: Tree Root Constraints

You cannot add 3.5 feet of fill over mature maple roots—it will kill the tree. Compaction and pH change from gravel are fatal. Keep the deck or explore alternatives: lighter composite decking (Eon, Fiberon), light-colored boards (cooler feet), or outdoor linoleum over wood. Composite runs 25%+ over pressure-treated ($15/sf installed).

If the tree stays, the deck stays. Design around it.