Whole-system duct and dryer vent check with before-and-after photos - you see exactly what came out of your vents
That "$99 whole-house special" is a bait ad - the real number appears once they are in your hallway, or the "clean" is a shop-vac at the register. We photograph the inside of your ducts before and after instead.
Fast, Reliable Duct Sealing Across Martha Lake
We seal ducts in Martha Lake homes where damp crawl spaces and 1960s rigid-metal trunk lines have been pulling musty air through the joints for decades. Our dispatch team coordinates from the Seattle office, and our crews serve Martha Lake directly – no third-party contractors, no vague arrival windows. When you call (361) 326-5060, a live person answers, 24 hours a day, and we book you a real appointment with a background-checked, uniformed technician who arrives inside the quoted window.
Martha Lake’s lakefront ramblers and split-levels aren’t like the newer construction in neighboring cities. The original ductwork here was built for a different climate standard, and the additions that followed often created mismatched, leaky runs that compound the moisture problems from the nearby wetlands. We know these homes because we’ve worked on them. That local knowledge changes what we look for, where we look, and how we fix it.
Why Hollis Air Duct Cleaning Is Martha Lake’s Preferred Duct Sealing Company
We’ve been part of the Garrison Partners family since 2004, and our Martha Lake reputation is built on showing up when we said we would, pricing the job in writing before any work starts, and standing behind it for a full year. The 365-Day Done Right Promise means if our seal fails, we come back and make it right at no charge, including a free second visit. No negotiation, no runaround.
Our technicians carry professional-grade equipment from Rotobrush and Nikro, and we stock filtration products from Honeywell, Aprilaire, and Guardsman for Martha Lake jobs that need more than sealing alone. Every tech is background-checked, uniformed, and expected to work by The Garrison Code: arrive inside the window, price in writing, complete the job by the book, leave the site clean.
Calls are answered by a live person, 24/7. No voicemail loops. No callback queues. No waiting until Monday for a scheduling question about your Martha Lake home.
HVAC Duct Sealing in Martha Lake
HVAC Duct Sealing in Martha Lake addresses the specific failure pattern we see in this market: rigid-metal trunk-and-branch systems from the 1960s – 70s that terminate into damp crawl spaces, pulling lake and wetland moisture through separated joints. The job involves pressurized testing to locate leaks, sealing accessible joints with mastic and mesh, and re-balancing airflow so the system doesn’t overwork itself drawing from the wrong places. In Martha Lake, a typical residential duct sealing job runs $450 – $850 for a single-system home, with larger split-levels or homes with additions running $750 – $1,200 depending on access and the extent of the crawl-space work.
Most Martha Lake homeowners call us after noticing musty smells when the heat kicks on, rooms that never reach temperature, or utility bills that climbed without explanation. The damp marine climate here means these symptoms often trace back to moisture intrusion at the duct joints, not just dirty ducts.
What We Seal First
We start with the crawl-space branch runs, not the easy-to-reach basement trunk. In Martha Lake’s near-lake homes, this is where the actual moisture enters. Sealing only the accessible trunk line while leaving the crawl-space joints untouched is a common shortcut that wastes your money and leaves the musty smell intact.
Pressurized Leak Detection
We pressurize the system and measure static pressure loss to find leaks you can’t see with a flashlight. This tells us exactly which joints are pulling unconditioned air, and how much. The numbers go on your written estimate before any sealing begins.
Duct Repair in Martha Lake
Duct Repair in Martha Lake goes beyond sealing when the original rigid-metal ducts have corroded at the seams, rodent damage has compromised a branch run, or a 1980s addition created a flex-duct splice that’s collapsed or disconnected. We replace damaged sections with properly sized metal or sealed flex, rebuild supports so ducts don’t sag and collect condensation, and verify airflow balance across the system. Typical duct repair in Martha Lake runs $350 – $650 for isolated section replacement, with full branch-run rebuilds in older homes reaching $800 – $1,500.
The housing stock here – original lakeside cottages expanded with additions – often has duct paths that make no sense on paper. We’ve found branch runs that dead-end into walls, returns that pull from unconditioned attics, and supply lines that were never properly connected after a remodel.
Corrosion and Moisture Damage
Martha Lake’s months of high humidity corrode metal duct seams from the outside in, especially in crawl spaces that never fully dry. We cut out the damaged section, fabricate a replacement, and seal it to the existing trunk with proper transitions – not duct tape, which fails in damp conditions.
Rebalancing After Repair
A repaired duct system needs balanced airflow, or you’ll end up with some rooms overcooled and others starved. We measure supply and return at each register and adjust dampers or add returns as needed. The goal is even comfort, not just moving air.
Trusted Brands We Service in Martha Lake
We carry professional-grade equipment and stock parts from Rotobrush, Nikro, Honeywell, Aprilaire, and Guardsman for Martha Lake jobs. Rotobrush rotary brush systems handle the mechanical cleaning that often precedes sealing work in these older rigid-metal systems. Nikro negative-air machines maintain containment so dislodged debris doesn’t redistribute through your home during the job. For homes that need filtration upgrades alongside sealing, we source Honeywell and Aprilaire media filters and Guardsman UV systems – the same products commercial crews specify, sized for residential ductwork. Having these parts on hand means faster turnaround for Martha Lake homeowners, not a two-week wait for a specialty order.
Common Duct Sealing Problems We See in Martha Lake Homes
- Crawl-space moisture intrusion at branch joints. In Martha Lake’s near-lake ramblers, the original rigid-metal trunk often terminates into damp crawl spaces where branch joints have separated from decades of expansion and contraction. We seal these with mastic and mesh, not tape, because tape fails where there’s persistent moisture.
- Musty odors misdiagnosed as dirty ducts. Homeowners pay for standard cleaning when the real problem is unsealed joints pulling damp, microbial-laden air from the crawl space. A blow-and-go cleaning doesn’t fix the source; sealing the joints does.
- 1980s additions with mismatched flex-duct splices. The original 1960s metal system was never designed to handle the airflow demands of an added wing, so flex-duct was cobbled in with inadequate supports. These splices sag, kink, and leak at every connection point.
- Fall debris and rodent nesting in returns. After the rainy season, we regularly find insulation fragments and nesting material clogging returns in Martha Lake homes, especially where crawl-space access screens have gaps. This restricts airflow and forces the system to draw from leak points instead.
Pricing for Duct Sealing in Martha Lake, WA
A typical residential duct sealing job in Martha Lake runs $450 – $850 for a single-system home with standard access. Split-levels, homes with 1980s additions, or properties requiring extensive crawl-space work typically fall in the $750 – $1,200 range. Duct repair, when sections need replacement rather than sealing, runs $350 – $650 for isolated fixes and $800 – $1,500 for full branch-run rebuilds in older homes.
What moves the price: accessibility of the crawl space, extent of joint separation, whether the system needs rebalancing after sealing, and whether we find rodent damage or corrosion requiring repair before sealing can be effective. We give you one flat price per system, agreed in writing before any work starts. No per-vent pricing. No add-ons at the door. Estimates are free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near Martha Lake
Our crews work throughout the Puget Sound region, and we regularly schedule Duct Sealing in Martha Lake alongside jobs in Seattle, Spokane, Tacoma, and Vancouver. Each location operates independently under The Garrison Standard, with the same written pricing, background-checked technicians, and 365-Day Done Right Promise. If you’re outside Martha Lake city limits but in the broader service area, we can still book you – just mention your neighborhood when you call.
Serving Martha Lake, WA - Our Local Coverage Area
We’re based in the Martha Lake area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Duct Sealing in Martha Lake
Martha Lake sits lower in the Puget Sound lowlands, closer to the lake itself and adjacent wetlands, so ambient moisture stays higher year-round and crawl spaces rarely dry out completely. The original 1960s – 70s rigid-metal systems terminate directly into these damp spaces, and when branch joints separate, the system pulls that moist, microbial-laden air straight into your living space. Homes on higher ground or farther from standing water simply don’t face the same sustained humidity at the duct level. Call (361) 326-5060 if you’re fighting a musty smell every heating season – we’ll run a camera inspection and show you exactly where the air is coming from.
Yes. The original trunk-and-branch system was sized for a smaller footprint, and the 1980s addition typically involved cobbling in flex-duct with inadequate supports and poor sealing at the transition points. We find these splices are often the leakiest part of the system, sagging in crawl spaces and pulling unconditioned air. Our sealing work addresses both the original metal joints and the addition’s flex connections, then rebalances airflow so the new wing isn’t starved. Call (361) 326-5060 for an assessment of your specific layout.
No. Fogging masks the musty smell for a few weeks but does nothing about the damp air being drawn in through unsealed joints. We were called to a 1968 split-level near Martha Lake Park where the homeowners had already paid for two fogging treatments that did nothing. Our tech ran a camera inspection and found branch runs had separated at the crawl-space joints, pulling wet soil air straight into the system. We sealed those joints with mastic and mesh, re-balanced the system, and the odor was gone by the second heating cycle. The fogging was a waste; the sealing fixed the source. Call (361) 326-5060 and we’ll show you the actual problem before quoting any work.
It can. Debris in returns after the rainy season often means your crawl-space access screens have gaps, allowing rodents to nest in or near the ductwork. Restricted returns force the system to work harder and can increase negative pressure at leak points, pulling even more unconditioned air. We clear the debris, seal the access gaps, and then seal the duct joints so the system draws from the right places, not the crawl space. Call (361) 326-5060 for an inspection after the fall rains if you’re seeing this pattern.
Musty smells that return every heating season, rooms that won’t hold temperature, and utility bills that climbed without explanation point to leakage, not just dirt. A standard cleaning removes debris from inside the ducts but doesn’t stop moist outside air from entering through unsealed joints. We offer camera inspections that show you the condition of the joints and the source of any moisture intrusion. If the ducts are intact and the issue is accumulation, cleaning may suffice. If the joints are separated or corroded, sealing is the fix. Call (361) 326-5060 and we’ll diagnose it honestly – no upsell for work you don’t need.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Martha Lake since 2004.




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