How to Stop Squirrels Chewing Your Deck

Squirrels chew decking for minerals and tooth wear. Their incisors grow continuously, and salt-contaminated timber tastes better than a branch. Remove the salt, treat the edges, and cap the worst of it with metal.

Step 1: take the salt away

This is the part that gets skipped, and it is the reason the deck was chosen over a tree.

• Keep de-icing salt off the deck in winter — sand or grit on the steps instead
• Wash the timber down in early spring, especially railings, stair nosings and the areas near doors
• Clear spilled food and drink. Sugary spills and barbecue grease both leave residues
• Sweep up spilled birdseed daily, or move the feeder 15–20 ft away
• Handrails collect salt from hands — give them the same wash

Chewing often spikes in late winter and early spring, which is exactly when de-icer has soaked into the wood and natural food is scarcest. That timing is the clue.

Step 2: treat the chewed areas

Apply to the surfaces actually being chewed rather than the whole deck. Squirrels work edges — the top of a railing, the nosing of a step, a corner post, the lip of a joist — because an incisor needs an edge to bite around. Those are the square feet that matter.

Step 3: cap the edges with metal

The only permanent fix, and it is cheaper than it sounds because you are covering edges, not areas.

• Aluminium or galvanised flashing bent over a railing top, screwed down
• Stair-nosing trim on the steps
• Corner protectors on posts
• Hardware cloth stapled along the underside of a chewed joist edge

Where a railing has already been destroyed, replacing the top rail with a composite board solves it permanently — composites get gnawed far less because there is no mineral reward in them.

Step 4: reduce how many squirrels the garden supports

• Move or baffle bird feeders, and sweep the ground beneath
• Switch to hulled seed so there is no shell litter
• Use pepper-treated birdseed — birds are unaffected, mammals are not
• Prune branches back about 10 ft from the deck; squirrels jump 6–8 ft
• Smooth metal bands on posts, and guards on downpipes

What does not work

• Mothballs and naphthalene. A registered pesticide, illegal used this way in many places, and genuinely hazardous in a semi-enclosed outdoor space
• Ultrasonic repellers. No reliable evidence
• Fake owls and plastic snakes. A few days, then ignored
• Greasing the railings. Ruins the finish, traps birds and insects, and they find another route
• A salt lick “to give them an alternative”. It draws more squirrels to the deck, which is the opposite of the goal
• Poison. Not legal for squirrels in many jurisdictions, and it kills whatever eats the poisoned animal

Repair the damage promptly

A chewed edge is a marked edge. It carries scent, it offers a ready-made grip for the next animal, and bare untreated end grain absorbs water. Sand it back, treat it, and cap it in the same visit — otherwise the same six inches get re-opened every spring.