Once bats are out, the next priority is making sure they can never return. Bat proofing is the comprehensive layer of work that seals every potential entry point on your home — soffits, fascia, roof vents, chimney flashings, gable ends, and the surprising small gaps that bats squeeze through. We use stainless and copper mesh, custom-fit vent guards, and exterior-rated sealants. Backed by our Lifetime Warranty.
When proofing makes sense
Bat proofing is preventive work — comprehensive sealing of a home's vulnerable entry points whether or not bats are currently active. There are three common scenarios where it's worth doing:
- After exclusion. If we've just completed a bat exclusion at your home, the proofing portion was already part of that work. We mention it here for clarity: every exclusion includes proofing.
- Neighbour or street has had bats. Colonies migrate. If a neighbour has had bats and the colony has been excluded from their home, the bats often look for the next-best option nearby. Proofing in advance is the cheapest insurance.
- Older homes you've just bought or inherited. Cedar shake roofs, stone construction, and century homes are the highest-risk for entry points. Proofing during the move-in period — before you've moved your stuff into the attic — is the easiest time to do it.
What we proof
Bats can squeeze through gaps as small as one centimetre. The most common entry points on a typical home are:
- Soffit and fascia gaps — the number-one entry point. Wood shrinkage and joints between sections create the openings.
- Roof vents — gable vents, ridge vents, and soffit vents almost always need custom-fit guards. Off-the-shelf vent guards typically have gaps where they meet the roof line.
- Chimney caps and flashings — the metal flashing where the chimney meets the roof is a common entry point. Even a small gap can admit bats.
- Loose siding seams — wherever siding meets a corner or trim board, gaps can form. Proofing involves resealing these.
- Eaves and rooflines — anywhere two roof planes meet (valleys, dormers, ridges) needs inspection.
- Gable end vents — typically louvered for airflow; we add fine mesh behind the louvers to block bats while preserving ventilation.
- Attic dormer windows — the trim where a dormer joins the main roof is often imperfectly sealed.
Materials we use
We don't compromise on materials. The cost of doing this work twice is much higher than the cost of doing it once with the right components:
- Stainless or copper mesh — rust-proof, lifespan exceeds the home itself. Aluminum mesh corrodes when paired with steel fasteners; we never use it.
- Custom-fit vent guards — fabricated to match the specific vent shape on your home. Off-the-shelf guards leave gaps.
- Polyurethane sealant rated for exterior wood — paintable, UV-stable, flexible enough to handle wood expansion and contraction.
- Galvanized screws — no aluminum-on-steel mismatch corrosion; fasteners that last as long as the home.
Bat proofing vs. bat exclusion — what's the difference?
Proofing is preventive (no active bats). Exclusion is removal plus proofing — when bats are currently in the building, we install one-way valves, wait for them to leave, and then proof every entry point. The proofing portion of an exclusion is the same work we do on a standalone proofing job.
When you bundle proofing with exclusion, the proofing portion is discounted as part of the exclusion job. If you're not sure which you need, our free inspection will tell you — bat-active homes need exclusion; bat-free homes need proofing.
Lifetime Warranty
If a bat re-enters through any point we sealed, we come back and do all the work necessary — at no extra cost. Forever.
The same warranty that covers our exclusion work covers our standalone proofing work. Full terms in our Terms of Service.
Pricing
Every home is different. Standalone proofing (no existing bat issue) is typically less expensive than full exclusion because there's no wait period and no valve installation. Get a free, no-obligation quote after a brief inspection.
Frequently asked
How do bats get into a house?
Bats squeeze through gaps as small as half an inch — about a centimetre. The most common entry point is the soffit-fascia junction, where the roof meets the wall. From there: unscreened roof vents, gable vents, chimney flashings where they meet the roof, loose siding seams, and unsealed dormer trim. Older Ontario homes are at the highest risk. Cedar shake roofs, century homes, and stone-construction houses all have natural gaps that bats find easily. Even newer homes with a single missing piece of trim or a lifted soffit corner can host a colony. The forensic-level inspection we do during a quote walks the entire envelope — every soffit, vent, joint, and flashing — because missing one access point means the exclusion fails. We typically find six to fourteen entry points on a single home.
How small a hole can a bat fit through?
Smaller than most homeowners imagine. Little brown bats squeeze through gaps less than half an inch — about one centimetre. Big brown bats need about five-eighths of an inch. The practical test: if you can stick a pencil through a gap, a little brown bat can squeeze through it. This is exactly why bat-proofing requires forensic-level inspection. We routinely find access points that the homeowner has walked past for years without noticing — a lifted shingle corner, a hairline gap where the soffit meets the brick, a vent screen with a torn edge.
Do bat repellents work?
No. Ultrasonic devices, scent-based repellents, lights left on in the attic, mothballs, predator-scent sprays — none have been proven effective in independent testing. Some may move bats around inside the structure, which actually makes the problem worse: bats relocate from the attic into the wall cavities, where they are harder to find and harder to remove. The only proven method is physical exclusion: one-way valves to let bats out, then permanent sealing of every entry point. Save the money you would spend on repellents and put it toward a real exclusion that lasts.
What does the lifetime warranty actually cover?
If a bat re-enters through any point we sealed, we come back and do all the work necessary — at no extra cost. Forever. Coverage applies to every entry point our team sealed during the original exclusion. The warranty is transferable to new owners if you sell the home, with no expiration date. What it does not cover: entry points we did not seal (a new gap that opened after our work), points created by storm damage or third-party renovation, or substantial renovation that compromises the original sealing work. Full terms in /terms.
How much does bat removal cost?
Honest answer: it varies. Costs depend on home size, the number of entry points, how long the colony has been active, and whether attic cleanup and decontamination are needed. We do not publish a fixed range because every home truly is different — a small home with four entry points is a very different job from a similar home with fourteen, and a five-year-old infestation that has soaked the insulation is a different job from one caught in the first season. Every home is different. Get a free, no-obligation quote after a brief inspection. Most exclusions in our Grey Bruce Simcoe service area fall in a typical range, which we will share during the on-site inspection once we have actually seen what the job involves.