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 Rowland Heights
Duct sealing in Rowland Heights typically runs $450 – $1,200 for a whole-house seal on original 1970s – 90s ductwork, and most jobs are scheduled within a few days of your call. We dispatch crews from our Los Angeles office to serve Rowland Heights directly, and we know the local housing stock: the slip-joint metal trunks, the sagging flex runs in Puente Hills attics, and the fine gray ash that gets pulled through soffit vents after brush fires. If your registers blow dust even after a cleaning, the problem is usually leaks, not dirt. Call (361) 326-5060 for a free estimate and written price before any work starts.
Why Hollis Air Duct Cleaning Is Rowland Heights’s Preferred Duct Sealing Company
We’ve been working in the San Gabriel Valley since 2004, and Rowland Heights homes follow a pattern: original rigid metal ductwork with slip joints that separate, flexible attic runs that sag and collect debris, and rodent intrusion from the Puente Hills foothills. Our Duct Sealing team has sealed hundreds of these systems. We show up in the window we promised, in uniform, with background-checked technicians. The price is written down before we touch anything. Every seal is backed by our 365-Day Done Right Promise: if it fails, we come back and make it right at no charge, including a free second visit. That’s The Garrison Standard, and it’s how we operate in Rowland Heights.
Duct Sealing Services in Rowland Heights
Duct Sealing Services in Rowland Heights address the leaks, gaps, and disconnected joints that let conditioned air escape into your attic and let unfiltered attic air – dust, pollen, and wildfire ash – enter your living spaces. Most Rowland Heights homes built between the 1970s and 1990s have original ductwork that has shifted, rusted, or pulled apart at seams. Sealing restores the pressure boundary so your HVAC system moves air through the rooms you actually live in, not the crawlspace above them. A typical whole-house duct sealing job in Rowland Heights runs $450 – $1,200 depending on accessibility, the condition of the existing ductwork, and whether we need to replace crushed or rodent-damaged sections before sealing.
Leak Detection and Static Pressure Testing
We pressurize your duct system and measure static pressure loss to find exactly where air is escaping. In Rowland Heights, we commonly see 20 – 35% leakage on original systems – air you’ve already paid to heat or cool, lost to the attic. We mark every leak, show you the readings, and quote the seal before we start.

Mastic Sealing and Mechanical Fastening
We seal metal seams and flex-to-trunk transitions with duct mastic – a thick, flexible compound that outlasts tape – and reinforce with mechanical fasteners where joints have pulled apart. On a 1978 ranch home off Fullerton Road, our crew found the original slip-joint metal supply trunk separated at a seam and a sagging flex run in the attic that had been chewed by rodents; we performed source removal under negative pressure with HEPA filtration, then sealed the trunk seam and transition with mastic and mechanical fasteners. Post-sealing static pressure dropped and the homeowner noticed less dust on registers within a week, confirming the ash-laden bypass was finally closed.

What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Duct Insulation in Rowland Heights
Duct Insulation in Rowland Heights wraps your sealed ductwork in thermal barrier material to prevent heat gain in summer and heat loss in winter. Rowland Heights’s hot inland summers push attic temperatures past 130°F, and uninsulated metal ducts act like radiators, warming your cooled air before it reaches the register. Most local homes have minimal or degraded original insulation, if any. Adding insulation after sealing typically runs $600 – $1,800 for a full system in Rowland Heights, depending on linear footage and whether we’re working around existing obstructions in tight attic spaces.
R-Value Assessment and Material Selection
We measure your existing insulation’s R-value and specify replacement or augmentation to meet current California Title 24 standards. For Rowland Heights’s climate zone, we typically specify R-6 or R-8 flex duct insulation or foil-faced fiberglass wrap on rigid metal trunks. We use Guardsman and Abatement Technologies products rated for residential HVAC applications.
Vapor Barrier and Condensation Control
Rowland Heights’s dry climate reduces condensation risk, but monsoon-season humidity spikes and occasional winter rains can still create moisture problems in poorly insulated ducts. We install vapor-barrier-facing insulation with sealed seams to prevent condensation that leads to mold growth and duct degradation.
Trusted Brands We Service in Rowland Heights
We stock sealing and insulation materials from Aprilaire, Abatement Technologies, and Guardsman – the same products commercial HVAC crews use – so Rowland Heights customers don’t wait on special orders. Our Rotobrush rotary brush systems and Nikro negative-air machines handle the cleaning that must precede any effective seal. We carry mastic, mechanical fasteners, foil tape rated for high temperatures, and rigid metal repair sections for the slip-joint trunks common in local homes. If your system needs a component we don’t have on the van, our Los Angeles office coordinates same-day or next-morning pickup.
Common Duct Sealing Problems We See in Rowland Heights Homes
- Separated slip-joint seams on original metal trunks. The 1970s rigid metal ductwork in Rowland Heights attics was joined with slip joints and a few screws. Decades of thermal expansion and vibration open these seams, and the negative pressure in supply ducts pulls attic air – loaded with Puente Hills dust and ash – straight into your breathing air.
- Sagging, crushed flex duct in attic runs. Flexible duct serving back bedrooms in Rowland Heights ranch homes often sags between joists, creating low points where debris collects and airflow chokes. The flex tears at the collar, disconnects from the trunk, or gets chewed by rodents entering from the foothills.
- Rodent-damaged sections that need replacement before sealing. Sealing over contaminated, chewed flex is a waste of money. We remove the damaged section, close the entry point with screening, and install new flex or rigid metal before we seal the system tight.
- Fine gray ash coating duct interiors after brush fires. After fires in the Angeles National Forest, ash settles on Rowland Heights roofs and gets pulled through soffit vents into attic ducts. If your ducts leak, that ash recirculates through registers. Sealing stops the bypass; cleaning removes the residue.
Pricing for Duct Sealing in Rowland Heights, CA
Whole-house duct sealing in Rowland Heights typically costs $450 – $1,200. Partial sealing of a single zone or a few accessible leaks runs $250 – $500. Duct insulation added after sealing runs $600 – $1,800 for a full system. What moves the price: how much of the ductwork is accessible without cutting drywall, whether we need to replace rodent-damaged or crushed sections first, and whether your system needs cleaning before sealing (a dirty seal fails fast). 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 Rowland Heights
Our crews work throughout the San Gabriel Valley and northern Orange County. We regularly schedule Duct Sealing in Rowland Heights alongside jobs in Walnut, Brea, La Puente, and Hacienda Heights. Same standards, same written pricing, same 365-Day Done Right Promise in every city we serve.
Serving Rowland Heights, CA - Our Local Coverage Area
We’re based in the Rowland Heights 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 Rowland Heights
Rowland Heights’s location at the base of Puente Hills creates a steep temperature gradient and frequent inversion layers that trap dust, pollen, and wildfire ash from the Angeles National Forest; this means air ducts here clog faster and leak more aggressively than in coastal suburbs with onshore airflow. Sealing is what stops that ash-laden attic air from entering your supply ducts. Call (361) 326-5060 for a free estimate.
We pressurize the system and measure static pressure; if leakage exceeds 15%, sealing will improve comfort and air quality more than cleaning alone. We also inspect visually for separated seams, disconnected flex, and rodent damage – common in Rowland Heights’s original housing stock. Call (361) 326-5060 and we’ll show you exactly what we find.
We clean first, then seal; sealing over ash-coated ducts traps contaminants and creates a future mold risk. We use HEPA-filtered negative-air machines to remove ash, then seal the leaks that let it enter. Call (361) 326-5060 to schedule both steps.
We seal with professional-grade mastic and mechanical fasteners, using Abatement Technologies and Guardsman materials, and we clean pre-seal with Rotobrush rotary brush systems and Nikro negative-air machines. These are the same tools commercial crews use, not hardware-store substitutes.
Sealing alone won’t remove odors, but it prevents your return system from pulling unfiltered air – including cooking exhaust – from leaks in the duct path. For odor issues, we typically recommend sealing plus upgraded filtration with Aprilaire media cleaners, which we can install during the same visit. Call (361) 326-5060 to discuss your specific setup.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Rowland Heights since 2004.




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