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 Portland, Rockland and the surrounding Southern and Coastal Maine areas 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
  • 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
air sealing 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
Evergreen employees in attic

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
  • 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 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.

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 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

I am very pleased with my experience with Evergreen Home Performance. I met several times with Richard Burbank and he was very detailed in his explanations to all of my questions. He provided me with several options for improving the insulation to our home. The team of installers were very professional and respectful of our home. They did a great job of cleaning up every day after the days work and they were also very responsive to all my questions as well as we collaborated to get our home better insulated. It was a pleasure to work with Richard and…

Brian C.

Falmouth

Professional, friendly and hard-working staff. The product/approach they use for insulation is top notch. We felt the difference immediately, both from added warmth and eliminating drafts. The team and management were easily available to answer our questions or coordinate meeting times. Highly recommended.

Kevin J.

Yarmouth

They were highly recommended. I found them to be very knowledgeable and so helpful, with practical ideas. Despite my not living within their service area, they were generous with their knowledge, describing the usual solutions to correct leaks in my basement, and what the result is likely to be by following path A, B or C, and why. I was discouraged. Talking with Evergreen helped me see that my basement problems are far from insurmountable and really, fairly common in 100-year old homes. There are proven solutions.

Rosalind J

Damariscotta

We initially contacted Evergreen through Efficiency Maine for an energy audit, which was conducted promptly and professionally by Justin McEdward, one of their Energy Advisors who is BPI-certified. After a thorough inspection of our newly purchased home, Justin explained in great detail what we needed and did not need. It was agreed that Evergreen would remove all of the existing attic insulation, which was not adequate, and replace it with blown in cellulose, to a rating of R-60.

Thomas W.

Scarborough

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

We are thrilled with the job Evergreen did to transform our 213 year old home into a warm, draft-free, cozy space. The entire team led by Bruce was prompt, courteous, knowledgeable, and hard working. If Evergreen could transform our home in this way, we are sure they would make a comparable difference in YOUR home!

Jonathan M.

Bridgton

Evergreen did an amazing job insulating our historic home. Their professional staff worked hard to ensure the tough areas in the attic were covered, and clearly communicated their progress. We are seeing the results with our discounted heating bills. Thank you, Evergreen!

Melissa Knoll

Portland

Evergreen came back this year to finish insulating our house. We have been remodeling and renovating an 1850s cape for several years. Their employees are very professional and pleasant to deal with. Over several years Brian Robinson has been able to schedule us in for several small areas that needed addressing and finally turning a room we used to close off in the winter into a comfortable usable space. We primarily heat with wood and since Evergreens great work our furnace has only come on ONCE this winter. Fantastic. Really satisfied customer in Thomaston.

Chris F.

Thomaston

Evergreen came out 2 years ago to do an assessment and insulate our roof. This year we had them come back and do the basement as well. They are hands-down the best crew we've ever hired to work on our house. They are experts at what they do, and super meticulous in their work. After working in our house for a week with blown insulation, there was no trace they were ever here. We've seen a huge decrease in our energy bills while at the same time the house has become way more comfortable. Can't recommend them enough.

RC Lations II

Portland

I was extremely pleased with the professionalism and quality of service that I received from the Evergreen team. I met Richard to discuss options for insulation. I knew immediately that I wanted to do business with them because he did not try to over-sell extra services that I did not need. Dave was the project manager. He was not only kind, but very respectful of my home. I would highly recommend this company.

Darlyann M

Bath

A thorough inspection of our (older) house and its energy needs. Competent and personable work crew.

Jacob Watson

The Evergreen crew from initial inception to installation were professional, on time, and left our place spotless. The end result was exceptional.

John Brown

Evergreen has a professional and reliable team of people who do excellent work. If you want the best of the best in the area, select Evergreen to accomplish your insulation needs.

Mary E.

St. George

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