Roofline, soffit and fascia
Mice are climbers. The roof edge is out of sight from the ground, and a small opening up there leads straight into the attic.
Where to look
- The seam where the soffit panels meet the fascia board, all the way along the roof edge.
- Corners where two roof edges meet, and the ends of the fascia boards.
- Soffit panels that have sagged, cracked or pulled out of their channel.
- Gnawed or rotted wood at the roof edge, and any spot with dark, greasy rub marks.
The rule of thumb: if a gap is about the width of your finger, a mouse can use it.
Why mice use it, and the common mistake
Why mice use it
Warm air collects under the roof, and the attic above it is quiet, dry and full of nesting material. A mouse that climbs a wall, a downspout or a branch reaches the roofline easily, and any gap about the width of your finger is enough to get in.
Common DIY mistake
Stuffing the gap with spray foam alone. It looks sealed from the ground, but foam is soft. Mice chew right through it, and the gap is open again.
The lasting fix
Close it with stainless steel or galvanized hardware cloth, or exterior-grade metal, sealed in with exterior-grade adhesives and sealants.
The lasting fix, step by step
Walk the whole roofline
From the ground with a flashlight or binoculars, follow the roof edge all the way around the house. Mark every gap, sag or chewed spot you find, not just the first one.
Clean and dry the area
Brush off loose debris, old foam and nesting material so new material can bond to a clean surface.
Cut the metal to fit
Cut stainless steel or galvanized hardware cloth, or exterior-grade metal flashing, so it covers the opening with overlap on solid material on every side.
Fasten it down
Fasten the metal to solid wood or framing with exterior-grade screws or fasteners, so it can't be pushed or pulled loose.
Seal it in
Seal the edges with exterior-grade adhesives and sealants so there's no lip for a mouse to grip or gnaw.
Replace rotten wood first
If the fascia or soffit is soft or rotted, replace that section before you seal. Metal fastened to rotten wood won't hold.
On a shared building, the roof edge and soffits are usually common property. Talk to your HOA or building manager before any outside work.
Materials
- Stainless steel or galvanized hardware cloth
- Exterior-grade metal flashing
- Exterior-grade screws or fasteners
- Exterior-grade adhesives and sealants
- Tin snips, gloves and eye protection
Safety notes
- Roofline work means ladders. Use a sound ladder on firm, level ground, and have someone hold it.
- Don't walk on tile or steep roofs. If you can't reach a spot safely from a ladder, leave it to a pro.
- Wear gloves and a mask around droppings and nesting material, and don't sweep or vacuum them dry.
Before you seal the last gap
- Make sure nothing is still living inside. If mice are already in, set indoor snap traps along the walls as you seal, never as a substitute for sealing.
- Keep food, pet food and birdseed in sealed containers.
Want us to look at your house?Send photos from your walk-around and we'll send back a custom plan: each gap marked, what to seal it with, and in what order.
Mouse-proof my house