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I invite you to explore my YouTube channel, where you'll see first-hand how insulation looks in dark and mysterious attics, crawl spaces, and basements scattered across Maryland. Witness first-hand how we tackle the unique challenges found in these hidden spaces, and gain valuable knowledge on how to conquer your own house.

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Eric Gans
Certified Energy Auditor

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I invite you to explore my YouTube channel, where you'll see first-hand some of the issues we are out there fixing.

Monday, May 12 2025
Hidden Air Leaks, Cold Rooms, and the Crawl Space That Changed Everything

If you’ve ever walked into a room in your home and thought, “Why is it always freezing in here?”, you’re not alone. And the answer isn’t always what you think.

I was recently called out to a home in Maryland to do a complete energy audit for a family dealing with, you guessed it, cold floors, uneven temperatures, and high energy bills. It wasn’t a huge home, and from the outside, everything looked normal.

But what I found inside told a completely different story.


The Setup: Drafty Room, High Electric Bills, and Suspicion About the Crawl Space

When I arrived, the homeowner mentioned that their electric bill had soared over $1,100 during the winter. And the kicker? They weren’t even using the entire house.

That’s when I started digging, literally and figuratively.

We ran a blower door test to see how leaky the home was. The air just poured through. But where it was leaking from… that’s where things got interesting.

Eric Gans blower door test Maryland


The Crawl Space: Moisture, Gaps, and Unwanted Guests

The crawl space wasn’t fully open but wasn’t encapsulated either. The homeowner thought it was semi-conditioned, but it was in limbo. There were signs of past rodent activity, visible air movement through cracks, and a vapor barrier that had been mostly sealed but not completely.

The biggest problem?

  •  Massive gaps in the rim and band joists.
  •  Holes were cut for ductwork that opened straight to the exterior siding.
  •  No insulation in key areas.

When I say I could touch the back of the aluminum siding from inside the house, I mean it.

maryland rim joist insulation expert

This wasn’t just an insulation problem. This was a major connection point to the outside and a straight shot for cold air infiltrating the home. No wonder they had high energy bills.


Stack Effect in Action

Upstairs, I found classic signs of the stack effect. An invisible force where hot air rises and escapes through the top of your home, pulling cold air up from the bottom.

You could feel the airflow at the recessed lights and attic access hatch. Even the insulation looked as if it had been shifted by the wind, a phenomenon known as wind washing, which was happening above the daughter’s bedroom. The wind had pushed the insulation away from the edges, exposing the ceiling and causing severe temperature fluctuations.

attic wind washing example


The Real Fix: Sealing the Bottom AND the Top

Here’s what we recommended, and why it works:

Crawl Space Encapsulation:

  • Fully seal the vapor barrier (which was already partially installed, a good start!).

  • Insulate the crawl space walls, not the floor above. This brings the space into a semi-conditioned zone.

  • Use rigid foamboard and 2-part spray foam to seal rim joists and large cutouts.

  • Eliminate outside air intrusion (and mouse pathways).

  • Result: The ducts and subfloor stop losing heat, moisture drops, and pests stay out.

crawl space encapsulation diagram

Attic Improvements:

  • Targeted air sealing at top plates, bath fans, electrical cutouts, and chase ways.

  • Install baffles to prep for possible future soffit ventilation.

  • Add loose-fill cellulose to bring insulation levels to R-49.

  • Insulate and weather-strip the attic access hatch to complete the boundary.

Bath Fan Venting:

  • Reroute bath fans that are currently terminated at gable vents.

  • Properly vent them outside, as required for rebate eligibility and indoor air quality.

 


Unexpected Bonus: Loose Duct Discovered

While inspecting the attic, I found an unsecured elbow joint on a duct supplying a second-floor bathroom. It was barely attached and likely leaking heated air into the attic. We reconnected it, but it must still be sealed and appropriately fastened to improve duct pressure and conditioned air delivery.


The Bigger Picture: What Makes a Home Truly Comfortable

You can buy the best HVAC system in the world, but it'll never feel right if your home leaks air like a sieve. Insulation is only part of the equation. Air sealing is the hidden hero, and it’s almost always overlooked.


If You Live in an Uncomfortable Home, Start Here

Your home isn’t broken, it’s just misunderstood. That’s what energy audits are for.

  • We diagnose the invisible issues
  • We quantify how much energy (and money) you’re losing
  • We build a prioritized plan, no fluff, just results

And with rebates available through Maryland's BGE & PEPCO Home Performance with ENERGY STAR® program, many of our recommended improvements qualify for thousands in incentives.


Book your $100 home energy audit now
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Let’s find the comfort you’ve been missing, hiding in plain sight.

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