Squirrels and Metal Roofs: What They Can and Cannot Do

A squirrel in the attic is one of the more common reasons people call about a roof, and it is a fair question whether a metal roof would have stopped it. The honest answer is that it would have stopped the part of the roof squirrels attack, and it would have done nothing about the part they usually use. Here is how they get in, what metal changes, and what it does not.

How squirrels get in

Squirrels do not chew through a sound roof surface. They work an edge that has already softened or a gap that was never closed.

• Fascia and eave decking. Years of ice damming leave the first foot of the roof edge soft. A squirrel gnaws into that in an afternoon, and the hole is the size of a fist.
• Gable vents and soffit vents. A rusted or missing screen is an open door. Squirrels widen a gap with their teeth.
• Lifted shingle edges. On aging asphalt, the edge of the roof is loose enough to get a nose under. Once through the shingle, the plywood is next.
• Roof-to-wall joints and dormer corners. Wherever trim meets trim and the joint has opened up.

They get up there from trees. A branch within ten feet of the roof is a bridge. A bird feeder near the house is an invitation.

What they do once they are in

Chew. Insulation gets torn up for nesting. Wiring gets gnawed, which is the genuinely dangerous part. Stored things get ruined. And the entry hole lets water in along with the squirrel, so the roof problem and the pest problem grow together.

What a metal roof changes

The roof surface stops being a target. No animal is chewing through steel, and a standing seam or interlocking metal shingle roof has no loose edge to get a nose under. The eave is hemmed over metal trim. The field of the roof is out of play, and that is the part of an asphalt roof squirrels actually open up.

It also tends to get the edges fixed. A re-roof is when rotten fascia and eave decking get replaced, because the old roof is off and the damage is visible. A metal roof over fresh trim with a proper drip edge is a hard edge.

What a metal roof does not change

Here's the tradeoff. The vents, the soffits, and the trim joints are not the roof. They are wood, screen, and caulk, and a squirrel that was using a gable vent will still use the gable vent.

• Vent screens. Replace rusted screens with heavy hardware cloth. A roofer can do this while the roof is open, but only if it is on the list.
• Closures. On a ribbed panel, the gap under each rib at the eave and ridge needs a foam or metal closure. Skip it and you have built a row of doorways.
• Trees. Keep limbs back from the house. This is the single most effective thing, and it is not a roofing job.
• Rotten wood. Metal trim over soft fascia covers the problem without fixing it. Ask that rotten wood be replaced, not wrapped.

If you have squirrels now

Get them out before the roof goes on. A wildlife contractor excludes them with one-way doors so nothing gets sealed in, then the gaps get closed. Sealing a squirrel in the attic makes a bad problem worse, and it is not something a roofing crew should be improvising. Once they are out and the entry points are closed, the roof's job is to not open any new ones, and a well-detailed metal roof does that for a very long time.

Who this matters for

If you have had squirrels, a metal roof takes the roof surface off their list for good, and the rest depends on the edges and vents being done right. Ask about those by name. If you have never had them, this is not a reason to buy a metal roof. It is something that comes with one. There is a broader piece on pests and metal roofs if raccoons or bats are the problem instead.

Now you know where to look.