Insulating a Freeport basement to help new heat pumps perform

“We were so glad that we did this.” – Lynne, homeowner in Freeport, ME

Jump to: The problem | What we did | The results | Free consultation

Summers in Freeport kept getting hotter, so Lynne and her husband put in heat pumps. While the installer checked the electrical panel in the basement, he pointed out that the new system would do more with insulation along the rim joists and basement walls.

He had seen it work in a home about the same size, one his daughter had just bought. When Lynne asked who he would call, the answer was short. Evergreen.

The short version

  • Air leakage dropped about 19%, from 3,130 to 2,530 CFM50
  • The damp basement walls cleared up, even through a hot, humid summer
  • The house holds its heat better, including an upstairs bedroom that used to run cold

The problem: a leaky basement, damp walls

Open rim joist bays above a bare concrete basement wall before insulation in a Freeport, Maine home
Before: open rim joist bays and a bare concrete foundation wall.

Lynne never dealt with flooding or standing water. What she did get was moisture on the basement walls in hot, humid weather, enough that her husband would set up a fan. Their heat pump water heater helped, but the moisture still showed up.

The basement door also leaked a lot. An Evergreen advisor came out, explained the Efficiency Maine rebates clearly, and never pushed. Everyone she dealt with “took their time with us” and “made sure all our questions were answered.”

Blower door fan mounted in a doorway with a red panel during an air leakage test
Before the work, a blower door test measured the home’s air leakage at 3,130 CFM50.

What we did: the rim first, then the walls

Rim joists and foundation walls

The crew started at the rim joists, where the framing meets the foundation and cold air finds its way in. They removed the old fiberglass, air sealed the cavities, and filled them with dense-pack cellulose behind a membrane to bring the rim up to about R-30.

From there, they covered the foundation walls about four feet down with foil-faced rigid foam. Next to the electrical panel and the chimney, they used mineral wool, which stands up to heat.

Basement wall covered in white rigid foam with a sealed rim joist above, after rim joist and basement wall insulation in Freeport, Maine
After: rigid foam down the foundation wall and a sealed, taped rim joist above it.

Lynne almost stopped at rim joist insulation. “We almost just did the joist, but I talked my husband into the walls, too,” she said, “and we’re really glad about that.”

Rim joist insulation sealed with foam and air barrier tape along the top of a basement wall in Freeport, Maine
After: rim joist bays sealed and taped.

The chimney and the basement door

Where the chimney passes through the floor framing, the crew sealed the gap with sheet metal and fire-rated caulk. It is an easy place for air to leak, and one that calls for fire-safe materials.

Concrete block chimney meeting the floor framing in the basement before air sealing
Before: the chimney chase where it meets the floor framing.
Chimney chase sealed with sheet metal and red fire-rated caulk where it meets the basement floor framing
After: sheet metal and fire-rated caulk seal the chimney chase.

The basement door was the other big leak. The crew weatherstripped it and fitted it with foam board. Lynne’s verdict: “it’s great.”

Basement door insulated with white foam board and a wood latch, with mineral wool and tape above the door frame
After: foam board and weatherstripping on the basement door.

When the unexpected came up

Right at the end, while the crew was vacuuming up, they hit a valve on the water heater. Lynne put it at about 10 gallons of water, “all over the basement just when they were done.”

Evergreen was back with a dehumidifier and took care of the cleanup. Lynne had a plumber redo the valve and someone out to help dry the basement, “but they paid for all of it.” She said her advisor and the project manager both stayed in close touch until it was sorted out.

Older Maine homes are full of surprises, and sometimes the unexpected comes up. When it does, we will never leave you in the lurch. We will do whatever we can to make it right.

Richard Burbank, owner, Evergreen Home Performance
Richard Burbank of Evergreen Home Performance smiling outdoors in front of purple flowers

The results: a drier basement, a warmer house

Evergreen’s post-project blower door test measured the home’s air leakage at 2,530 CFM50, down from 3,130 CFM50 before the project. That is 19% less air leaking through the house.

Air leakage before and after (CFM50)Before the project3,130After the project2,53019% less
Air leakage measured by blower door test, in CFM50. Lower is tighter.

The moisture is gone, too. Lynne’s advisor was upfront that he could not promise a result, but he thought she would see an improvement. Then came a hot, humid summer. “Our basement was perfect,” she said. “There’s no moisture buildup.”

The biggest change showed up in winter. “We were noticing how much warmer the house felt,” Lynne said. The upstairs bedroom, which has its own heat pump, used to run cold. She and her husband are sleeping better.

The room where she does her consulting work was always cold in winter. She credits the heat pump and the insulation together: “It’s been so comfortable between the heat pump and the insulation underneath us. It’s been fantastic.”

Richard Burbank of Evergreen Home Performance smiling outdoors in front of purple flowers

Most Maine homeowners want the same thing: a house that feels good in January and still feels good in August. New equipment helps, but it works best in a house that holds on to the air it has already heated or cooled. The basement is one of the easiest places to start.

Richard Burbank, owner, Evergreen Home Performance

The crew worked three or four long days straight. “They worked so hard,” Lynne said. “Evergreen was responsive every step of the way. And we really appreciated that.”

“It was so beautifully done, so professionally installed,” she said. For anyone weighing the cost and wondering whether it is worth it, her answer is short: “It’s worth it.”

Front entry of a Freeport, Maine cape with cedar shingles, a covered porch, and a stone walkway through the garden
Lynne and her husband’s Freeport home, where the basement upgrades helped the new heat pumps perform.

Your Maine home deserves the same attention

If your house never seems to hold the comfort you are paying for, the cause is often somewhere you cannot see, like a basement or a rim joist. An energy audit can find out exactly where, and a good plan fixes the cause instead of guessing.

Call 207-594-2244 or reach out to schedule your free consultation.

Evergreen Home Performance proudly serves homeowners in Freeport, Portland, and communities across Southern and Midcoast Maine with professional insulation, attic insulation, air sealing, and energy audits.

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 is the "go-to" company for improving the efficiency of your home. There are others to choose from but none so effective, honest, and capable as Evergreen. They did a great quantity of dense packing cellulose to improve our home (both for energy efficiency and for sound insulation) and it was totally successful. They are on-time, helpful, and caring. They clean up to a level that can't be over emphasized. This was the second time we employed them and we'd use them again if the opportunity came. You'll not be sorry to select Evergreen.

Dirk F.

Belfast

This team of individuals was professional at all times. They set up barriers that kept the dust at a minimum. They conducted an air flow audit and cut the draft circulation from the outside in half by sealing cracks. They hauled out the old insulation and replaced it with blown in insulation with an R - 60 Value. They also did the rebate paperwork so that I could get my $1500.00 rebate from the state of Maine. I highly recommend Evergreen Home Performance!

Daniel B.

Rockland

Working with Brian and with Nate and the rest of the crew was a pleasure. They made everything very easy and understandable. This was a major renovation and they were always at the ready with a lot of information. We had an extensive renovation on the basement which was a dirt basement and it came out beautifully. We can already tell from all of the insulation work what a difference it's made in sound and temperature. Brian worked with me on the rebates that are available when you do this kind of work. I would highly recommend this company to…

Valerie L.

Rockland

Highly recommended. Our heating usage is now less than half what it was before we had our roof insulated. Evergreen was knowledgeable, friendly, and left no trace they were ever in our house. Not only is our heating bill much lower now, but our home is generally more comfortable year-round with less temperature fluctuations. Money well spent.

RC Lations

The Evergreen team was amazing from initial assessment and planning to the crew that came to complete the work. Our basement encapsulation is the best money we've spent on our house by far. The work was thorough and high quality. And what a wonderful group of people to work with. I highly recommend Evergreen!

Martha Bracy

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

Evergreen did a fantastic job insulating our 1930's home. The onsite team was professional, clean, and really just a joy to interact with throughout the process. A blower test at the end showed a significant decrease in air leakage. I highly recommend Evergreen.

Kristen H.

South Portland

Thanks Evergreen Home Performance for helping to make our home more efficient. Many thanks as well to Bryan for the initial walk through and recommendations to make our home more efficient and to Dave, Roland, and Jacob for a job that was done professionally and courteous.  We were amazed at the level of efficiency and everyday they made sure to protect our floors, carpets, and furniture. We had daily discussions with Dave about progress and what was being done and where they were at in the project.

Carol Fink

Evergreen is a terrific company to deal with. Polite and efficient crews, meeting deadlines and major reduction in our heat bills. They corrected a lot of issues we suffered from doing work with a shoddy building contractor. We would recommend them to anyone.

Mary Carey

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

We had a fantastic experience working with Evergreen to insulate our roof this winter. Everyone was extremely friendly throughout the process - the crew at our home worked hard, were approachable with questions, and the team leader even showed me around the project to point out specific areas they were working to improve.

Joel Wentz

Evergreen completed the work at my home thoroughly and professionally. An inspector from Efficiency Maine came to inspect afterwards and described it as "state of the art" and "outstanding". The crew was very pleasant and considerate during the project. Their cleanup each day was perfect. Communications with the office were easy and reliable. I am very satisfied.

Catherine H.

South Portland

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

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

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