Case Study: Multi-Family AerSeal

Project Overview

Location: St. Louis, MO

Building Type: 3-story, 4-family brick apartment building

Size:  3,900 Sq. Ft.

Project Goal: Meet 2021 IECC air sealing standards of 3.0 ACH50 in a century-old multi-family building to support an EnergyStar rating & enhance energy efficiency, tenant comfort, & long-term property value.

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Challenges

Despite proactive measures by the owner, the building’s age and design created substantial sealing challenges:

- Exposed brick walls with embedded cracks

- Deep-set window cavities

- Gaps in original wood flooring

- Air leakage pathways into adjacent units

- Unknown leakage zones typical of pre-20th century structures

Solution: AeroBarrier by TJ Wies Sealing Solutions

TJ Wies used AeroBarrier—an advanced aerosol-based sealing system designed to identify & fill leaks from the inside out.

Our team:

- Prepared and pressurized the space

- Performed baseline testing (Results showed 11.1 ACH50 on the first unit)

- Conducted a detailed AeroBarrier application, requiring extended time & multiple days due to the building’s complexity

- Achieved a final blower door result of 2.5 ACH50, significantly outperforming the target

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Before & After

• Initial Air Leakage: 11.1 ACH50
• Final Air Leakage: 2.5 ACH50
• Reduction: 82.8%+ improvement

(See report for full leakage data)

Benefits

• Noise barrier
• Pest barrier
• Improve indoor air quality
• Reduce energy & consumption costs
• Improve building ventilation
• Meet code & specs

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