Why Your Crawl Space Insulation is Failing: Lessons We've Learned

Crawl Space Insulation Fails Often, But Why?

If you've noticed cold floors, uneven room temperatures, high humidity inside the house, musty odors flowing through the vents, or a moldy smell when the HVAC turns on, your crawl space insulation may be failing.

When you look at your insulation, is it drooping? Does it have dark stains? Are there signs of pests or droppings? Is it moldy or even wet and heavy? This is an indication that your insulation is no longer working, and it's time to do something about it.

Robert C., Alford Real Estate Response Specialist, shares his 20+ years of expertise in home inspections and crawl space repair to walk you through why it may be failing and how to prevent it from failing next time.

1. The #1 Reason Your Insulation is Failing is Moisture!

If your crawl space is even just a little damp, so is your insulation. And when your insulation is damp, it loses its ability to do its job. When it's wet, it can also grow mold easily. Mold loves any insulation that includes organic materials like paper.

Fiberglass floor insulation and moisture are a bad combination.

2. Incorrect Installation

We've seen a few installation errors. You can't squish fiberglass insulation down to fit it into a cavity. It actually needs at least 1/2 inch of air space to allow the air to pass through it. That's how it effectively keeps in heat. 

You also can't place insulation upside down. We see this a lot. We should see the vapor barrier up against the floor. This means while standing and looking up, we should see fiberglass, not paper. Besides, paper-based fiberglass is a playground for mold.

3. Open vents

Are there open vents in your crawl space that lead outdoors? Those will quickly kill your insulation and cancel out any attempt you had at blocking out cold drafts. Sealing the vents permanently keeps the insulation working and your home a lot drier and energy efficient.

How to Prevent Insulation Failure Long Term

First, insulation should be installed against the crawl space walls and floors to maximize effectiveness. Since the wood floor system above the crawl space is full of gaps, pipes, and ducts, it's really the wrong place to insulate. 

Instead, by insulating the walls and crawl space floors, and sealing outside vents, the crawl space becomes an extension of the rest of your home--a well-conditioned space. 

A crawl space encapsulation is the best way to properly insulate your crawl space from floor to wall. This includes stopping water leakage at the source, isolating your home from the earth with a vapor barrier, sealing the vents and windows, and dehumidifying the air. 

To learn more or get a free estimate on proper insulation and crawl space encapsulations, give us a call: 1-304-768-2135.