How Mountlake Terrace Family Winterized Their Crawl Space

Lior Pinhas
February 17, 2025
Blog, Crawl Space Insulation, Projects, Rodent Prevention, Vapor Barrier Installation
crawl space, crawl space vents, free crawl space inspection, insulate air ducts, insulate floors, insulate pipes, mountlake terrace, winterize, winterize crawl space

When a family from Mountlake Terrace reached out for a crawl space inspection in January, they had one goal in mind: to ensure their crawl space was properly insulated and protected before the winter months winter arrived. They wanted a clean, well-insulated crawl space with professionally sealed air ducts and a new vapor barrier. Additionally, they were concerned about potential rodent activity and wanted mitigation measures in place.

Identifying Problem Areas During Inspection

The estimator discovered several issues that were compromising the efficiency and health of the homeowner’s crawl space during the inspection:

Sagging and insufficient insulation
Poorly insulated and unsealed air ducts
Rodent damage
Loose, ineffective vapor barrier.

Sagging and Insufficient Insulation

Crawl Space Before Winterization – Sagging Batt Insulation And Insufficiently Insulated Air Ducts

The existing paper-backed floor insulation was installed backwards and in poor condition. It no longer provided adequate thermal protection, leading to heat loss.

Poorly Insulated and Unsealed Air Ducts

The HVAC air ducts lacked consistent insulation, causing uneven heat and inefficiency throughout the home. Additionally, they were not sealed, allowing warm air to escape, further reducing energy efficiency during the winter months. The lack of insulation and proper sealing also allows for more moisture and contaminants from the crawl space to enter the system, contributing to poor indoor air quality and potential mold growth.

Rodent Damage

Evidence of rodent activity, including chewed insulation, and damaged vents, indicated a need for thorough cleaning and exclusion measures. Without intervention, this could lead to further structural damage and potential health concerns.

Loose, Ineffective Vapor Barrier

The old vapor barrier was loose, dirty and no longer provided the moisture protection needed to keep the crawl space dry.

Crawl Space Winterization Process

Overall, we installed a new vapor barrier, wrapped the water supply lines, and installed R25 fiberglass batt insulation to provide lasting thermal protection and moisture control. Here are a few detailed steps in this crawl space winterization process:

Remove all damaged materials, including the old vapor barrier, insulation, and any animal waste.
Sanitize the entire space with a disinfectant solution.
Seal all possible rodent entry points.
Address air leaks around plumbing, air ducts, and electrical penetrations to improve energy efficiency.
Seal the air ducts at all joints, corners, and saddles with mastic, rubber-like paste.
Wrap the air ducts with R11 fiberglass insulation to ensure consistent heating and prevent heat loss.

Family’s Crawl Space Ready for Winter and Beyond

Winterized Crawl Space With New Batt Insulation, Insulated Water Lines And Air Ducts

After completing the project, the family immediately noticed a significant difference. Their home felt warmer, their heating costs decreased, and the risk of moisture buildup was eliminated. Most importantly, they felt confident that their home was safeguarded against the winter’s cold air and moisture for years to come.

Ready to Winterize Your Crawl Space?

If your home is experiencing cold floors, higher energy bills, or signs of moisture and rodent activity, it may be time for a crawl space upgrade. Call us at (253) 315-0172 to schedule a free crawl space inspection today and let our professionals help prepare your home for the seasons ahead!