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.
Service
What Does Exterior Gap Sealing & Pest Exclusion Include?
Exterior gap sealing and pest exclusion covers every accessible outside penetration on the house — plumbing and electrical service entries, dryer-vent and bath-exhaust hoods, hose-bib gaskets, foundation-to-band-joist seams, soffit gaps and attic-vent screens, plus the cable, satellite, and smart-home entry holes left unsealed by previous installers. Weather sealing closes air and water paths. Pest exclusion closes the path mice, rats, yellow jackets, hornets, paper wasps, and bats use to get into walls, attics, and crawl spaces. Same exterior-grade sealants, different prep — and at any gap a mouse can pass through (a 1/4-inch hole is enough for a mouse, 1/2-inch for a rat), the right answer is copper mesh packed behind the sealant. Mice chew through caulk and expanding foam alone; they cannot chew through copper.
Plumbing and Electrical Service-Line Penetrations
The holes where the main electrical service drop, the gas line, the supply water line, and any low-voltage cabling enter the house. The original installer drilled a hole 1/2 inch larger than the line for clearance — and very few of those holes get properly sealed afterwards. We pack the annular gap with copper mesh, top with exterior-grade polyurethane, color-matched to the siding or trim paint.
Dryer-Vent Perimeter and Bath-Exhaust Hood
The dryer-vent perimeter is one of the top-three rodent entry paths on most homes — the hood is screwed to siding with a 1/4-inch reveal all the way around, and the original installer's caulk has usually failed within five years. Same fix at bath-exhaust hoods on exterior walls and at range-hood penetrations through siding. Copper mesh at the perimeter (sized to the actual gap), exterior polyurethane on the visible bead, the vent hood itself reseated if it has come loose from the siding.
Hose-Bib Gaskets and Foundation Penetrations
Frost-proof hose bibs penetrate the foundation or band joist through a 3/4-inch hole; the rubber gasket that came with the bib has usually failed within three to five years from UV exposure and freeze-thaw cycling. We strip the failed gasket residue, pack copper mesh if there is any annular gap, top with exterior polyurethane, and color-match if visible to the siding.
Foundation-to-Band-Joist Seam and Sill-Plate Gap
The horizontal line where the wood band joist sits on top of the concrete foundation — at the rim joist behind every exterior wall. The gap between the sill plate and the concrete is a continuous air-and-rodent path that runs the whole perimeter of the house. The original construction usually used a thin sill-seal foam that has compressed over decades. We seal the visible exterior seam (where accessible from outside) and call out interior-side work (rim joist sealing from inside the basement or crawl space) as a separate scope.
Soffit Gaps and Attic-Vent Screens
Soffit-to-fascia gaps where the soffit panels have pulled away from the fascia trim — common on older homes, the path bats and wasps use to nest in attics. We seal the gap with exterior polyurethane and, where wasps are an active problem, install a fine stainless-steel mesh behind the bead. Attic-vent screen perimeters get inspected and re-sealed where the original screen has rusted through or pulled away.
Cable, Satellite, and Smart-Home Entry Holes
The holes the cable company, the satellite installer, the security-system installer, and the smart-doorbell installer drilled into the siding over the years. Almost all of these were sealed at install with whatever was in the truck (often standard latex caulk that failed in two winters) and now leak. We strip, pack mesh if there is any open gap, top with exterior polyurethane, and color-match.
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.
Walk-Around Exterior Inspection
Walk the accessible exterior — foundation perimeter, soffit line, every visible vent and pipe penetration, the corners where siding planes meet. Flag every entry path before sealing. Often the customer called about one obvious gap and there are three others they had not noticed.
Strip Failed Sealant and Clean
Strip every existing failed bead with a utility blade or solvent, brush the substrate clean, and let it dry. Standard interior latex caulk that the previous installer used (cable, satellite, smart-doorbell installers all default to it) fails outside in two winters and has to come off in full.
Pack Copper Mesh at Rodent-Rated Gaps
Any penetration where a mouse-sized animal could pass through (a 1/4-inch gap or larger) gets copper mesh packed behind the visible sealant. Mice chew through standard caulk in under a minute and through expanding foam in about ten — they cannot chew through copper.
Sandwich Wider Gaps with Expanding Foam
Gaps wider than 1/2 inch get a closed-cell polyurethane foam fill first (Great Stuff Pro Gaps and Cracks), trimmed flush after cure, then the visible sealant on top. At rodent-prone wider gaps the layered fix is mesh-then-foam-then-sealant — three lines of defense in one penetration.
Top with Exterior Polyurethane
Run the visible bead in exterior-grade polyurethane (Sika 1A or Loctite PL Polyurethane) — rated for 20 years of UV and plus-or-minus 25 to 50 percent movement. Hybrid MS sealants work as a paintable substitute. We do not carry interior caulk on exterior jobs.
Color-Match the Visible Bead
Polyurethane is paintable and available in white, almond, bronze, and brown stock — picked to match the trim or siding paint on arrival. Hidden penetrations (behind downspouts, under soffits) skip the paint step and the sealant stays in its native off-white finish.
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.
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.
Copper mesh behind the bead at rodent-rated gaps
Mice chew through standard caulk in under a minute, through expanding foam in about ten. They cannot chew through copper. Every penetration where a mouse-sized animal could pass through (a 1/4-inch gap or larger) gets copper mesh packed behind the sealant before the visible bead. The mesh is rated for rodent exclusion permanently; the sealant on top is the weather seal.
Exterior polyurethane, never interior caulk on a penetration
Exterior-grade polyurethane (Sika 1A, Loctite PL Polyurethane) is rated for 20 years of UV and ±25 to ±50 percent movement. Standard interior latex caulk fails outside in two winters. Hybrid MS sealants (DAP Dynaflex Ultra) work as a polyurethane substitute and accept paint faster. We do not carry interior caulk on exterior jobs.
Expanding-foam-and-sealant sandwich at gaps wider than 1/2 inch
Gaps too wide for caulk alone (the half-inch annular gap around a service drop, the inch-wide opening at a band-joist crack) get an expanding-foam fill first (closed-cell polyurethane foam — Great Stuff Pro Gaps & Cracks), trimmed flush after cure, then topped with the visible polyurethane bead. Mice will chew through foam, so when the gap is wider AND rodent-prone, the layered fix is mesh-then-foam-then-sealant.
Pest-exclusion inspection on every penetration visit
When we are out for one penetration, we do a walk-around of the accessible exterior — the foundation perimeter, the soffit line, every visible vent and pipe penetration, the corners where two siding planes meet. We flag any other entry path we see and quote them before sealing. Often the customer called about one obvious gap and there are three others they had not noticed.
Color-matched on visible exterior, sealant-finish on hidden
Polyurethane is paintable and available in white, almond, bronze, and brown stock — picked to match the trim or siding color. Where the penetration is hidden from view (behind a downspout, under the soffit), we leave the sealant in its native off-white finish and skip the paint step. We tell you on the booking call which approach applies.
Estimate
Active pest problem (rodents, wasps, ants), or visible penetration count, or last-time-rodent-inspection date — we will quote it.
Customer Reviews
Exterior gap sealing and pest exclusion reviews from real Handis customers.
We had been hearing mice in the wall for two months. The exterminator killed them but said unless we sealed the entry points they would come back. Handis tech walked the exterior, found three obvious gaps (dryer vent, an old cable hole, the gap behind the hose bib), packed copper mesh into each one, and topped with polyurethane. No mouse sounds in eight months.
Yellow-jacket nest in the soffit above the front porch last August. Exterminator dealt with the nest but we wanted to make sure it would not happen again next year. Tech found three soffit-to-fascia gaps, sealed them with exterior polyurethane and stainless mesh behind. No nest the next summer.
Dryer-vent hood was barely attached and the half-inch perimeter gap was an obvious pest highway. Tech pulled the hood off, packed copper mesh into the gap, reseated the hood with new screws into framing (not just siding), then ran polyurethane around the outside. Hood does not move and we have not had any signs of mice since.
Whole-home exterior penetration sweep before we listed. Tech walked the house, found nine penetrations that needed work — service drop, dryer, two cable holes, two old satellite holes, the hose bib, the gas-line entry, and a smart-doorbell hole the previous owner had drilled. Three and a half hours, all sealed. The home inspector for the buyer commented on the work.
Foundation-to-band-joist seam — the home inspector had flagged it during the buyer's inspection on our last move. This tech sealed the accessible exterior section with polyurethane and a thin run of foam where needed, then crawled in the crawl space and pointed out where the interior side still needed work. Did not try to upsell — just told us what was there.
Frequently Asked Questions
Common questions about exterior gap sealing and pest exclusion.