Can Spray Foam Fix Indoor Drafts and Air Leaks?

Spray foam insulation is an effective solution for sealing indoor drafts and air leaks. Unlike traditional insulation materials, spray foam expands upon application, filling gaps, cracks, and voids that allow outside air to enter a building. This direct air-sealing property helps create a continuous thermal barrier, reducing drafts and stabilizing indoor temperatures.

In practice, spray foam can address both minor and major sources of air leakage, including gaps around wall penetrations, attic floors, and foundations. For Seattle’s damp and fluctuating climate, effective air sealing prevents cold drafts in winter and minimizes moisture intrusion that can lead to structural issues. This makes spray foam a strong choice for energy efficiency and long-term comfort.

How Spray Foam Insulation Works

Spray foam insulation combines liquid chemicals that expand into a rigid foam when applied. The material adheres to surfaces and solidifies into a dense or semi-flexible barrier depending on the foam type. By sealing directly at the application site, spray foam stops uncontrolled airflow and improves building performance.

Comparing Spray Foam Types for Draft Control

Technical Performance Data for Spray Foam

Practical Insights from Experience

• Air leakage accounts for up to 40% of heating and cooling energy loss in U.S. homes according to the U.S. Department of Energy (DOE). Spray foam directly reduces this energy waste.
• Buildings in the Pacific Northwest benefit from closed-cell foam in exterior-facing walls and crawlspaces due to its moisture resistance.
• Bonus tip: For older homes, sealing attic penetrations with spray foam before insulating is more effective than layering insulation alone.

Things to Evaluate Before Deciding

• Building Age: Older homes often have hidden leakage paths that require a combination of sealing and insulation.
• Climate Conditions: Regions with high rainfall, such as Seattle, benefit from moisture-resistant closed-cell foam in certain areas.
• Access Points: Limited-access spaces like crawlspaces and rim joists are often the most impactful places to seal.
• Future Maintenance: Foam is durable but difficult to remove, so placement must be carefully planned.

Services That Address Drafts and Air Leaks

• Open-Cell Spray Foam: Best for indoor partitions and attics where sound dampening and thermal control are both priorities.
• Closed-Cell Spray Foam: Recommended for exterior walls, crawlspaces, and foundations where moisture protection is needed alongside air sealing.
• Attic Insulation: Prevents rising warm air from escaping and blocks cold drafts from entering through the roofline.
• Foundation Insulation: Reduces drafts from crawlspaces and basements that affect comfort on the ground floor.

Common Questions Before Insulating

Can spray foam be applied over existing insulation?

Yes, but only after assessing whether the old insulation is blocking air sealing effectiveness.

Does spray foam stop moisture leaks?

It stops air-driven moisture but is not a substitute for waterproofing systems.

Is spray foam safe indoors?

Once cured, spray foam is stable and non-toxic. Proper installation practices minimize risks during application.

How long does spray foam last?

When properly installed, it can perform effectively for the lifetime of the building.

Summary of Key Points

Spray foam insulation is a direct solution to indoor drafts and air leaks. Both open-cell spray foam and closed-cell spray foam options provide distinct benefits depending on building conditions. Effective application in attics, walls, and foundations reduces energy loss, improves comfort, and limits moisture risks in Seattle’s wet climate. Careful planning and selection ensure long-term performance.

Contact Cascadia Spray Foam of Seattle

For questions about sealing drafts and insulation options, contact Cascadia Spray Foam of Seattle at (425) 386-3500 or email [email protected]. The team provides expert guidance on residential and commercial spray foam applications across Seattle and surrounding areas.

FAQS

Can spray foam be painted?

Yes, closed-cell foam can be painted if desired, though a thermal barrier may be required by code.

Will rodents chew through spray foam?

Spray foam is not a food source, but rodents can gnaw through it if they are already present.

Does spray foam shrink over time?

High-quality spray foams remain stable; poor application may cause shrinkage.

Can spray foam be used in historic homes?

Yes, but it must be carefully applied to preserve ventilation and building integrity.

Is reapplication ever needed?

Typically no, but damaged sections may require touch-ups.