Air Sealing

Air Sealing

You deserve to feel comfortable all year long in your house. Air sealing and insulation locks in the warmth you’ve already paid for and stops drafts.

Most Maine homes have hidden gaps where indoor air escapes and unwanted outdoor air gets in. That air leakage makes your home harder to heat and cool, more expensive to run, and less comfortable to live in. Similar penetrations can also introduce basement and crawlspace air that’s been contaminated by moisture, radon, and unpleasant smells into your living spaces.

Evergreen Home Performance is a local insulation and air sealing company helping homeowners throughout Southern and Coastal Maine fix these problems at their source. Air sealing is an essential part of home insulation upgrades and a cost-effective energy efficiency improvement.

  • Eligible for up to $8,000 in Efficiency Maine rebates and $1,200 in federal tax credits
  • Reduce drafts, improve home comfort
  • BPI-certified experts using building science-backed solutions
Hands using an air sealing gun to apply caulk to gaps in attic
Applying caulk in an attic

Why Air Sealing Matters

  • Stay warmer in winter, cooler in summer
  • Eliminate uncomfortable drafts
  • Lower your energy bills
  • Improve indoor air quality

Combined with insulation, air sealing creates a powerful barrier between the living spaces in your home and the outdoors.

In addition to energy waste, leaky homes often pull in air from crawlspaces, basements, attics, and wall cavities—along with dust, mold spores, radon, and other pollutants. Sealing leaks gives you more control over your indoor air quality and along with proper ventilation can create a healthier, safer environment for your family.

How We Find the Leaks: Blower Door Testing & Thermal Cameras

Many times newer homes, including really nice ones built before Maine building codes adopted a blower door testing standard, are leaky due to confusion about roof venting and side attics. If you have a newer home and the floor over the garage is cold or pipes freeze in the master bathroom, you could have an air sealing problem that can be diagnosed with a blower door test.

Blower door testing and thermal imaging cameras show us exactly where the air is escaping. We use this building science technology during our energy audits so we can seal the right spots for real results. We then run a blower test again after work is completed to confirm the difference your upgrades made!

Evergreen Home Performance Team Air Sealing Attic

Evergreen – The Leading Air Sealing & Insulation Company Near You

  • More than 4,500 Maine homes improved since 2006
  • More BPI-certified professionals than any other Maine contractor
  • Over 15,000 home energy audits completed
  • More Efficiency Maine insulation rebates secured for customers than any other contractor in 2024
Evergreen Home Performance Team Air Sealing In Attic

Attic Air Sealing

Attic air sealing helps slow the stack effect, where warm air escapes out of the top of your home and cold air is pulled in from your basement or crawl space to replace it.

Common areas we air seal in Maine attics include:

  • Attic hatches and access doors
  • Chimney chases
  • Side attics (particularly in Cape Cod-style homes of all ages)
  • Lighting fixtures, fans, and vent penetrations
  • Plumbing and wiring penetrations
  • Wall top plates and framing joints

After air sealing, we blow in cellulose insulation for comprehensive attic protection.

Basement & Crawlspace Air Sealing

Your basement or crawlspace is another major source of air infiltration and leaks in your home. In these areas, we often use some combination of rigid foam board and foam gun insulation, which is both an insulator and an air sealant, giving you maximum protection as well as moisture resistance.

Common areas we air seal in Maine basements include:

  • Rim joists
  • Foundation walls
  • Bulkhead doors and access hatches
  • Chimney chases and other floor penetrations
  • Gaps around pipes, wires, and vents

Air sealing and insulation is just one component of our basement waterproofing services. When combined, these solutions not only stop air leaks but also protect your basement from moisture and mold.

Encapsulated Crawl Space

Airtight & Healthy: Why Ventilation Matters

As we reduce leaks and block outdoor pollutants with air sealing, we also make sure your home has enough airflow and proper ventilation. Without it, moisture and everyday pollutants originating inside your home—from cooking, showering, or just breathing—can build up.

This additional step ensures your Maine home is not just efficient—but safe, healthy, and comfortable too.

Save On Air Sealing with Efficiency Maine Rebates & Other Incentives

We helped more Mainers qualify for Efficiency Maine insulation and air sealing rebates than any other contractor in 2024!

  • Up to $8,000 in Efficiency Maine rebates
  • Up to $1,200 in federal tax credits for insulation and air sealing
  • Financing with payments as low as $50/month through Efficiency Maine Green Bank and NEIF

During your free consult, we’ll tell you all about available Maine energy efficiency loans, tax credits, and rebates, helping you maximize your savings.

Evergreen Team Reviewing Tax Credits and Incentives With Homeowner

Ready to make your home feel as comfortable as you want? We’re here to guide you every step of the way. Call 207-594-2244 or contact us today to book your free consult.

Take charge of indoor drafts and expensive energy bills

Evergreen is your guide on the path to a better home.

I made the mistake of NOT hiring this company last year when I bought and renovated my home. I have brought them in now and what a difference. This group knows what they are doing. They take a complete look at everything and believe they can make your home more energy efficient. They are very professional in the way they approach problems and solutions. And they find ways to save me money. Don't bother with anyone else. Bring Evergreen in before you do anything. Let them assess your issues and give you the right solutions.

Shaw

Owls Head

Evergreen did a fantastic job replacing 28 windows in our house. They were friendly, courteous, and very detail oriented. Brian did a great job planning, estimating and executing the project. Our energy use has dropped significantly since the work was done.

Alex B.

Kittery

Our basement was the eyesore of the house. I wanted to make improvements, but first needed to make structural, insulating and moisture mitigation improvements. Evergreen was professional and competent in taking on a complex project of not only encapsulation and insulation of basement and crawlspace, but completed needed improvements to the structural integrity of the wood floor platform above a crawlspace and brought in a concrete contractor to pour where there was once a rotting, tiered wood platform - replacing that area with a more functional and tight tiered concrete area.

Duane B.

East Boothbay

First we have Evergreen do a BIG project worth about $20K (windows, basement, insulate & rebuild an entire wall, a door, attics, and air sealing). They were so great we had them come back later when we decided we did want to do our other door. They are professional and do great work. They take care of your home and are trustworthy, and on top of all that friendly! I highly recommend you call them!

Garreth C Debiegun

The Evergreen Team did a fabulous job and was very tuned and responsive to the particular needs we had. The job was done right on budget and we are thrilled with the improved warmth and energy efficiency.

Ira M.

Rockland

From beginning to end – that is from the moment Justin McEdward stepped into our home to assess our energy conservation needs until the crew left – the Evergreen Home Performance process went absolutely smoothly. Justin made a thorough inspection and took pictures with an infrared camera. His proposal described the scope of work in detail, and he explained what we could expect the proposed work to accomplish. Our proposal was forthcoming within a couple of days, and Justin was available to discuss it and answer questions.

Adrienne Harkavy

Our house still the most efficient home we’ve ever lived in. And we have you folks to thank for that! A special howdy to Brian Robinson please!

Bruce O’Donal and Eva Butler

In the final stages of selling our home, and with a closing date set, an inspection came across an unanticipated issue in our attic. We quickly called in contractors, but nobody was able to identify the source of the problem. Then we thought of Evergreen. Brian Robinson was on site the next morning and immediately identified the source (a faulty roofing job completed three years earlier which had effectively sealed up portions of the ridge vent and restricted air flow - not easily visible with a quick inspection).

Robin McIntosh

Camden

Evergreen removed and replaced the insulation in my attic. They did a great job!, Crew was excellent, and the whole thing went smoothly, and the attic was NOT easy to get into or work in, so kudos to some hard work done well!

Joel A.

Portland

We are so pleased with the work the team from Evergreen Home Performance did in our home. The project included encapsulation of our basement with a reinforced vapor barrier, installation of a sump pump, spray foam insulation on the walls and insulation of the heating duct work. Everyone at Evergreen was friendly and professional. The project was completed on time and in budget. Our home is much cozier and warmer since the project was completed.

Linda Metzger

We had Evergreen energy do blow-in cellulose. I was very happy with the result. They tested with blower-door before and after. House is now MUCH warmer. Also, in the time since when I've had to open walls for various access, I've been impressed with how they got the insulation packed in everywhere. I'd use them again.

Noah

Peaks Island

I never leave reviews, but had a great experience with Evergreen and wanted to spread the word! In short, we worked with them to insulate our roof this winter and have noticed surprising immediate results. The constant ice dams I have wrestled with are completely gone, and the home is noticeably more comfortable. It's a little too early to tell if our oil bill is going to reduce, but I imagine we will see an impact there as well.

Joel W.

Portland

I would recommend Evergreen wholeheartedly because of their professionalism, their follow through, and thoughtful project planning.

Jennifer A

From start to finish, our experience was incredible. Justin was extremely helpful. The crew was fast, friendly, and efficient. And most importantly, our home is WAY warmer and our heating is less costly. I'd highly recommend evergreen to anyone looking to upgrade their home!

John S.

South Portland

Very easy process, start to finish.  Friendly, professional, and really know their stuff.  They made some improvements to our condo and we were very happy with how it played out.  Would definitely recommend them.

Clayton Eames

Portland Buy Local
Efficiency Maine
EPA Lead-Safe Certified
Building Performance Association
BPI Certified