Rotting boards can make a deck unsafe to use. Learn what may be behind the decay, what you can observe without approaching unstable boards, and when to contact a deck professional.

What may cause deck boards to rot

Wood can decay after prolonged moisture exposure. Poor drainage, debris that holds moisture, a worn protective finish, or aging wood may contribute. From the ground or another stable spot, look for visible discoloration, peeling finish, cracking, sagging, or water that lingers. Don’t walk on boards that look damaged or probe them.

When to arrange an inspection

Contact a deck professional if boards look decayed, cracked, or sagging, or if the deck shifts or feels unstable during normal use. Stay off any section that appears unsafe. A professional can assess whether the damage is limited to boards or involves other parts of the deck.

What to ask a deck professional

Ask which areas they’ll inspect, whether the visible damage appears limited to the boards, and what findings could change the repair scope. Request a written description of the proposed work and any safety limits on using the deck while you wait.

Choose the deck-building service path

Deck Building is the relevant service for an inspection or repair involving rotting deck boards. Continue to the Deck Building page for provider information.

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