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.
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Before
AfterGuardsman Duct Sealing & Repair: The Johns Creek Owner’s Guide
We stock and install Guardsman-compatible duct sealing and repair components for Johns Creek homes, with typical installed pricing between $340 and $780 depending on system access and the extent of seal failure. Most Guardsman sealing jobs we handle in the Medlock Bridge corridor and surrounding neighborhoods are completed in a single visit, with parts carried on our trucks. Homeowners usually discover the problem when rooms stop heating or cooling evenly, or when their energy bill jumps despite no thermostat change - the conditioned air is leaking into attics or wall cavities before it ever reaches the register.
Which Guardsman Models This Applies To
Guardsman duct sealing products fall into two main lines: the GS-100 series mechanical sealants used in residential flex-duct junctions, and the GS-300 series mastic-based sealing compounds applied to rigid metal trunk lines. The model number is stamped on a metal tag at the plenum box - the central distribution point where your HVAC system’s main trunk connects to individual duct runs, or branches, that serve each room.
We’ve found that Johns Creek homes built between 2015 and 2020, particularly the two-story zoned systems near the Chattahoochee River corridor, were often fitted with GS-200 transitional compounds that bridge mechanical and mastic applications. These are not interchangeable with GS-100 or GS-300 products. Using the wrong compound creates a brittle seal that cracks within two seasons of Georgia’s humidity swings. When we match parts, we verify the original application method - brush, spray, or tape-backed - because Guardsman’s OEM specifications vary by installation technique. CleanRun Air Duct Cleaning Johns Creek is an independent service provider, not affiliated with Guardsman, and we source both OEM Guardsman compounds and quality aftermarket equivalents from Abatement Technologies that meet the same ASTM E84 smoke-and-flame standards.
Signs Your Guardsman Duct Sealing & Repair Is Failing
- Uneven temperatures room to room. The most common call we get in Johns Creek: the master bedroom runs four degrees warmer than the hallway in summer. This usually means a seal has failed at a duct run junction, letting cooled air escape into the attic before reaching the register.
- Dust accumulation around ceiling registers. When seals fail on the return side - the ductwork that pulls air back to your HVAC unit - attic dust gets drawn into the system. We regularly photograph this in Johns Creek homes with original builder-grade sealing that has dried and pulled away from the collar.
- Spikes in summer electricity bills. A 15% jump in kWh usage without thermostat changes often traces to leaky supply ducts. Your system runs longer to hit setpoint because half the cooled air never arrives where you need it.
- Musty odor when the blower cycles on. Failed seals in humid crawl spaces or attics let unconditioned air carry mold spores into the ductwork. In Johns Creek’s clay-soil neighborhoods, where crawl spaces hold moisture longer, this shows up after sealant deterioration at trunk-line penetrations.
- Audible whistling near plenum connections. High-velocity air escaping through a gap in the seal creates turbulence you can hear. The sound typically starts small and worsens as vibration works the compound loose.
BeforeAfterReplacement Cost & What’s Included
Guardsman duct sealing and repair in Johns Creek runs $340 to $780 installed, with most single-point repairs falling between $340 and $520. The range depends on three factors we assess before quoting: how many linear feet of seal need replacement, whether the duct run is accessible from the attic or requires crawl-space entry, and whether the original failure damaged surrounding insulation that now needs restoration.
Every quote is written before work starts - Haven Standard Clause 1 - and includes the Guardsman-compatible compound or equivalent, surface prep and application, a pressure test to verify seal integrity, and the Documented Photo Record of every repaired junction delivered to you before we leave. The 365-Day Done Right Promise covers labor and materials; if a seal we applied fails within a year, we return and make it right at no charge. We do not quote per-vent or per-foot add-ons. The price you approve is the price on the invoice.
DIY or Call Us?
An owner can safely check two things: whether the plenum box tag is readable for model identification, and whether dust or daylight is visible around register boots from the attic side. Do not attempt to apply sealing compound yourself. Mastic compounds require specific mil thickness to cure properly; too thin and they crack, too thick and they sag before setting. Mechanical sealants need controlled tension on the backing tape or they delaminate within months.
More importantly, attic work in Johns Creek’s summer heat carries genuine risk - dehydration, wasp nests in eaves, and the hazard of stepping through ceiling drywall between joists. The photo goes first. The price comes after. If you’re seeing symptoms, call (470) 326-1926 and we’ll document what we find before quoting a dollar.
FAQs
Properly applied Guardsman sealant lasts 10 to 15 years in Johns Creek’s climate, though homes near the Chattahoochee with higher humidity may see 8 to 12 years before checking. Attic temperatures above 140°F in July accelerate curing compound degradation. Call (470) 326-1926 for an exact assessment of your system’s remaining seal life - estimates are free.
Small gaps under two inches can sometimes be bridged with compatible compound if the surrounding seal is sound, but we rarely recommend this. Patched seals fail at the interface 60 to 70 percent of the time based on what we’ve documented in Johns Creek homes. Full replacement of the compromised section, with proper surface prep, is the only repair we warranty under the 365-Day Done Right Promise.
Most single-point Guardsman sealing repairs take two to three hours from arrival to pressure test completion. Multi-zone systems with failures at several junctions, common in the larger two-story builds off Medlock Bridge Road, may require a full day. We stock GS-100, GS-200, and GS-300 compatible compounds on our trucks, so we rarely need a return visit for parts.
We carry Guardsman-compatible sealing compounds and application tools on every truck, including the aftermarket equivalents from Abatement Technologies that we use when OEM lead times run long. For Johns Creek calls, this means same-day repair in nearly every case. Call (470) 326-1926 to confirm compatibility with your specific model tag - we’ll verify stock before scheduling.
Ready to stop losing conditioned air to your attic? Call CleanRun Air Duct Cleaning Johns Creek at (470) 326-1926. Tomas Reyes or a member of his crew will answer, verify your Guardsman model if you have the tag, and schedule a free written estimate. Every repair includes the Documented Photo Record, the written price before work starts, and the 365-Day Done Right Promise - backed in writing, not just stated in marketing copy.
Written by Tomas Reyes, Owner, CleanRun Air Duct Cleaning Johns Creek at CleanRun Air Duct Cleaning Johns Creek, serving Johns Creek and nearby areas.