Air Sealing
Insulation slows heat transfer, but air sealing stops it, and most homes lose as much energy through air leaks as through their walls.
Air Sealing Services in St. Louis, MO
Insulation slows heat transfer, but air sealing stops it — and most homes lose as much energy through air leaks as through their walls.
The Hidden Energy Problem Most Contractors Miss
When homeowners think about energy efficiency, they typically think about insulation. But studies show that air leakage — uncontrolled movement of air through gaps, cracks, and penetrations in a home's building envelope — accounts for 25-40% of heating and cooling costs in a typical St. Louis home.
You can add as much insulation as you want; if air is bypassing it through gaps, you're still losing conditioned air and paying for it. Air sealing is the complement to insulation — without it, insulation is working at reduced efficiency.
Where Air Leaks Hide in a St. Louis Home
Top plates in the attic (biggest culprit — warm air rises and escapes through ceiling penetrations)
Recessed light fixtures in ceilings (each one is essentially a hole in your ceiling)
Plumbing and electrical penetrations through floors and ceilings
Attic hatch or pull-down stairs
Basement rim joists (major cold air entry point)
Ductwork connections and chases
Fireplace dampers and flues
Window and door frames (especially in older homes)
Exterior outlets and switches
How We Find Air Leaks — Blower Door Testing
A blower door test is the definitive diagnostic tool for measuring a home's air leakage. We install a calibrated fan in your front door, depressurize the home, and measure the total air leakage rate. This gives us an exact reading of how leaky your home is.
Combined with thermal imaging, this allows us to pinpoint exactly where the leaks are and prioritize them by impact. You'll have concrete data instead of guesswork.
Our Air Sealing Process
Blower door test to quantify leakage
Thermal imaging to locate leaks
Comprehensive sealing — spray foam for large gaps, caulk for small cracks, weatherstripping for movable components
Top plate air sealing in attic (the highest-impact single action in most homes)
Post-sealing blower door verification test
Documentation of improvement for utility rebate applications
Air Sealing and Ventilation — Getting the Balance Right
Important note: tightly sealing a home requires ensuring adequate mechanical ventilation. A home can be too tight for healthy indoor air quality if ventilation is not properly planned.
Quality Waterproofing + Insulation assesses ventilation needs as part of every air sealing project and recommends mechanical ventilation solutions when needed. We want your home to be tight and efficient, but not suffocating.
Benefits of Professional Air Sealing
25-40% reduction in energy bills possible
Eliminate drafts and cold spots
More even temperatures throughout the home
Improved indoor air quality (control where air enters)
Reduced moisture and condensation issues
Lower HVAC maintenance costs
Quieter home (less street noise infiltration)
May qualify for Ameren Missouri or Spire energy rebates
FAQ
Q1: How do I know if my home has air leaks?
A: Almost every home does. Common signs include drafts, high energy bills, uneven room temperatures, and dusty surfaces near electrical outlets. A blower door test gives you a precise measurement.
Q2: Is air sealing combined with insulation?
A: Yes — we almost always combine air sealing with insulation installation. The two work together; insulation without air sealing is significantly less effective.
Q3: How long does air sealing take?
A: A typical air sealing project takes one day. Larger homes or more complex situations may take longer.
Q4: Are there rebates available for air sealing in Missouri?
A: Yes — Ameren Missouri and other utilities offer rebates for air sealing and insulation upgrades. We can help you navigate the rebate application process.
Stop paying to heat and cool the outdoors. Quality Waterproofing + Insulation's air sealing services deliver some of the highest returns on investment of any home improvement project in St. Louis. Contact us for a blower door test and free assessment.
