Exterior Gap Sealing & Pest Exclusion

Exterior gap sealing and pest exclusion is the service that closes every accessible penetration on the outside of the house — utility entries, dryer vents, hose bibs, soffit gaps, foundation-to-band-joist seams — using exterior-grade polyurethane on top, copper mesh packed behind any rodent-rated gap, and an expanding-foam sandwich at gaps wider than half an inch, starting at $180 per penetration. The half-inch gap around the dryer vent that no one looks at, the cable-TV entry hole the previous installer never sealed, the hose bib where you can see daylight at the back of the gasket, the soffit gap where yellow jackets built a nest last August, the band-joist seam where mice are walking through every winter. Handis seals these once, with the right material, so the path is closed for the life of the siding.

Exterior gap sealing image — close-up of a freshly sealed dryer-vent perimeter on painted wood siding, copper mesh packed visibly behind the polyurethane bead at the larger half of the gap, the bead profile uniform and matched to the trim color.

Service

Photo of an exterior penetration sealing job — copper mesh being packed into the gap around an electrical service entry on painted fiber-cement siding, exterior polyurethane sealant tube and tooling rags staged on a drop cloth on the ground below.
Process

How Exterior Gap Sealing & Pest Exclusion Works

Six sequential steps from the walk-around inspection to the color-matched finished bead — the actual sequence we follow on every exterior gap sealing and pest exclusion visit.

Pricing

Exterior Gap Sealing Pricing

Final pricing depends on the number of penetrations, whether ladder work is required, and whether rodent-rated treatment (copper mesh behind the bead) is needed at any penetration. Request a free estimate for an accurate quote.

Tell us the visible penetrations or the active pest problem — we will quote a sweep.

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Why Handis for Exterior Sealing
Trust

Why Handis for Exterior Sealing

Pest exclusion is the work where the right material matters more than the right caulking technique. A mouse can chew through standard caulk in under a minute and through expanding foam in about ten — the mouse is not stopped by a bead, it is stopped by the copper mesh packed behind the bead. The exterminator who comes in after a rodent problem can kill the mice that are inside, but if the entry path is not closed properly the next generation walks back in two months later. We seal once with the right material so the path is closed for the life of the siding, not for the next eight weeks.

Estimate

Active pest problem (rodents, wasps, ants), or visible penetration count, or last-time-rodent-inspection date — we will quote it.

Service cost estimate illustration
Reviews

Customer Reviews

Exterior gap sealing and pest exclusion reviews from real Handis customers.

FAQ

Frequently Asked Questions

Common questions about exterior gap sealing and pest exclusion.

How much does exterior gap sealing and pest exclusion cost?
A single standard penetration (service line, dryer vent, cable entry) starts at $180. Three to five penetrations clustered on one wall is $260. A dryer-vent hood reseat plus reseal is $200. Hose-bib gasket reseal is $180. Soffit gap sealing runs $25 per linear foot with a $180 minimum. A foundation-to-band-joist seam (single side) is $260. A rodent exclusion inspection plus comprehensive seal is $400. A whole-home exterior penetration sweep (every accessible penetration on the house, ladder work included) is $550.
Why copper mesh? Why not just caulk?
A house mouse can chew through standard latex caulk in under a minute and through expanding polyurethane foam in about ten minutes. The same mouse cannot chew through copper. The CDC and the USDA both recommend stainless-steel or copper mesh as the standard for rodent-proof gap filling. We pack the annular gap with copper mesh, then top with exterior polyurethane sealant — the mesh is the rodent stop, the sealant is the weather seal. Caulk alone is not rodent-rated.
How big does a gap have to be for a mouse or rat to get through?
A house mouse can pass through a hole the size of a dime (about 1/4 inch). A Norway rat needs about 1/2 inch. Bats need a much smaller opening (3/8 inch is enough for most species). Yellow jackets and paper wasps need 1/4 inch. The takeaway — anything visible as a gap from outside is potentially a pest entry. We treat every visible gap as a rodent-rated penetration and pack mesh accordingly.
Can you seal up an active wasp or hornet nest entry?
No — and that order matters. A nest sealed in with the wasps still inside means the colony will tunnel out a new entry through your wall, often into the living space. Wasps and hornets need to be exterminated first (by a licensed pest-control company), then the entry path gets sealed once the colony is confirmed dead. We coordinate with the pest-control company on the schedule — usually their treatment goes in, we come a week later when the activity has stopped, and we close the entry.
Do you do the exterminator's work too?
No. We do exclusion sealing — closing the entry paths so pests cannot get in or get back in. The actual extermination of rodents, wasps, ants, or any other active pest is a licensed pest-control company's work, and Washington requires a structural pest inspector license for the inspection itself. We work alongside several local pest-control companies and can recommend one. The exclusion sealing is the long-term fix; the extermination handles whatever is already inside.
How long does an exterior penetration seal last?
15 to 20 years for properly installed polyurethane on a clean substrate. Copper mesh is permanent — it does not degrade. The sealant on top is the part with a service life, and the polyurethane products we use (Sika 1A, Loctite PL) carry 20-year manufacturer warranties when applied per spec. Cheaper products (standard latex caulk, generic exterior caulks) fail in two to three winters in Seattle and are not what we carry.
Can you seal under the soffit and around attic vents?
Yes. Soffit-to-fascia gaps are sealed with exterior polyurethane. At wasp-prone zones we install a fine stainless-steel mesh behind the bead so even if a future bead fails, the mesh layer still blocks entry. Attic-vent screens get inspected and re-sealed where the original screen has rusted through, the perimeter caulk has failed, or animals have torn a hole. We do not block functional attic ventilation — gable, ridge, and soffit vents stay open with their screening intact; we only seal the gaps around them.
What about the gap between the foundation and the band joist?
The horizontal seam where the wood band joist (the lumber that sits on top of the concrete foundation) meets the concrete is a continuous air-and-rodent path running the perimeter of the house. We seal the visible exterior section with polyurethane and minor expanding foam where the gap is wider than a half-inch. The interior side (rim joist sealing from inside the basement or crawl space) is a separate scope — typically done with closed-cell spray foam for both insulation and air sealing, and we route it to a weatherization contractor.
Will the sealant match my siding paint?
Yes. Polyurethane is available in white, almond, bronze, and brown stock colors — picked to match the trim or siding paint on arrival. For unusual siding colors, we use a paintable polyurethane and brush a coat of your siding or trim paint over the bead once it has skinned (15 to 30 minutes). For hidden penetrations (behind downspouts, under soffits, behind shrubs), we skip the paint step and leave the polyurethane in its native finish.
How long does an exterior gap sealing visit take?
A single penetration takes 20 to 30 minutes. A three-to-five-penetration zone on one wall takes 60 to 90 minutes. A rodent exclusion inspection plus comprehensive seal is two to three hours (the inspection walk-around alone is 30 to 45 minutes). A whole-home exterior penetration sweep on a 2,000 sq ft home is three to four hours including the walk-around, ladder work, and the time to color-match and tool every visible bead.
Is the work guaranteed?
Yes. 30-day workmanship guarantee on the sealing — if a bead pulls, cracks, separates, or shows visible failure within 30 days because of our workmanship or prep, we come back and redo it at no extra charge. The copper mesh portion is permanently rodent-rated and we will redo any mesh that comes loose at any time within 12 months. The guarantee does not cover pest activity that finds a different entry path we did not seal (we recommend a follow-up inspection visit if new activity appears) or damage from a structural problem unrelated to our work.

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