Many homeowners don’t realize that air leakage accounts for up to 40% of heating and cooling energy losses. Taking steps to properly air seal your home can significantly reduce wasted energy and lower utility bills. This guide will cover what an air sealing project involves, where leakage happens, best materials and techniques to use, and overall benefits for your home.

 

What is Air Sealing?

Air sealing refers to sealing all the gaps, cracks and openings throughout a building envelope where air can enter or escape. This uncontrolled flow of air, driven by temperature/pressure differences, represents a major form of energy loss.

Find the Gaps

Typical air leakage spots include cracks along baseboards, window and door frames, fireplaces, attic hatches, wiring/pipe penetrations, outlets, fixtures, vents and more.

Stop Unwanted Airflow

By sealing these gaps, you prevent heated or cooled air from escaping and outside air from entering. This minimizes energy waste.

Improve Efficiency

Careful air sealing creates a tighter, better insulated building that requires less energy to heat and cool. It’s a key efficiency measure.

 

Why Improving Air Sealing Helps

Upgrading air sealing provides multiple benefits:

• Lower utility bills by preventing costly heated or cooled air leakage
• Improve temperature consistency and comfort in living spaces
• Reduce dust/pollutants entering through leaks
• Prevent moist outside air from penetrating and causing condensation
• Complement added insulation so it performs optimally
• Improve humidity control which protects the home from mold risks

Air sealing delivers major efficiency gains and improved comfort at a relatively low cost.

Best Materials for Sealing Air Leaks

Several materials work well for sealing common air leakage points:

Caulk

Caulk forms a flexible seal for cracks and gaps. Use exterior grade for durability. Consider acoustical caulk to also reduce noise transfer.

Spray Foam

Foam sealants expand then harden to form an airtight barrier. Use minimally expanding foam near windows to avoid distortion.

Weather stripping

Adhesive-backed compressible foam strips make an air seal around windows and doors while allowing operation.

Draft Stoppers

Used for openings like attic hatches, these fiber-filled cushions expand to seal gaps when closed.

HVAC Mastic

A flexible, adhesive sealant used to seal duct joints and connections.

Using the right sealant for each leak point creates an effective air barrier.

Key Areas to Target for Air Sealing

Focus air sealing efforts in these problem areas:

Attics

Seal attic hatches, penetrations for wires/vents, junctions with walls, knee walls, etc.

Windows and Doors

Weather strip and caulk perimeter gaps and cracks around frames.

Ductwork

Seal all joints, connections and boot gaps with mastic and aluminum tape.

Fireplaces

Caulk around chimney flashing, pipe & wire penetrations. Install fireplace plugs when not in use.

Plumbing and Wiring

Fill openings around pipes, conduits, electrical boxes and fixtures with foam.

Basements

Seal sill plates, rim joists, penetrations through foundation walls and flooring gaps.

Focusing on common leakage hotspots provides the best return on investment for sealing efforts.

Performing an Air Sealing Project

Tackling an air sealing initiative in your home involves:

Inspection

Do a walkthrough to identify all potential leakage sites needing sealing.

Prioritization

Determine the largest and most accessible gaps to seal first for maximum effect.

Safety Checks

Turn off electric near any wiring you’ll seal. Check for asbestos before sealing ducts.

Air Sealing

Methodically seal identified leaks using caulk, weather stripping, foam and other materials. Work from top to bottom.

Ventilation Considerations

Maintain any combustion appliance venting needs. Add fresh air intake if increased tightness raises CO2 levels.

Testing

Verify air sealing effectiveness with blower door or incense smoke testing to check for remaining leaks.

Like any home project, careful planning and execution ensures successful air sealing results.

Benefits of Professional Air Sealing

For large homes or limited DIY time, consider hiring an foam insulation contractor to air seal:

• They have specialized diagnostic tools to find hidden air leaks.
• Professionals properly seal even tricky areas like ducts, sill plates and intricate framing.
• Expert caulking, foaming and weather stripping reduces call backs or rework.
• Airtight execution prevents wasted expense of heating or cooling air that leaks out.
• You gain peace of mind knowing the job was done thoroughly and correctly.

Investing in professional air sealing expertise delivers comfort and energy efficiency.

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