Mold in attics is a much greater/common problem than people think. This winter you should inspect for moisture.

Matthew Fournier 12/15/22

Condensation in attics can be a serious problem, especially when poor insulation and ventilation exist. This type of moisture buildup can lead to the growth of mold and mildew, which can cause a variety of health problems and damage to the structure of your home. In order to understand why condensation occurs in attics when poor insulation and ventilation exist, it's important to understand how moisture behaves in these conditions.

When warm, moist air comes into contact with a cool surface, such as the roof or walls of an attic, it will begin to condense. This is because the warm air loses its ability to hold onto moisture when it comes into contact with the cooler surface. As a result, the moisture in the air will begin to collect on the surface, forming droplets of water.


Poor insulation in the attic can exacerbate this problem by allowing the warm, moist air to easily come into contact with the cooler surfaces of the roof and walls. When the attic is not properly insulated, warm air from inside the home can easily rise up into the attic, where it will come into contact with the cooler surfaces and condense.


Similarly, poor ventilation in the attic can also contribute to the problem of condensation. When the attic is not properly ventilated, the warm, moist air from inside the home has nowhere to go, and will instead become trapped in the attic. This will cause the air in the attic to become increasingly warm and moist, increasing the likelihood of condensation on the surfaces of the roof and walls.



As mentioned earlier, when warm, moist air comes into contact with a cool surface in the attic, it will begin to condense and form droplets of water on the surface. These droplets of water can collect in various places in the attic, such as on the roof and walls, in corners and crevices, or on items that are stored in the attic. Over time, this moisture buildup can create the perfect conditions for mold and mildew to grow.

Mold and mildew are types of fungi that thrive in moist environments. When they come into contact with a source of moisture, such as the water droplets that form on the surfaces of the attic, they will begin to grow and spread. Mold and mildew can grow quickly, and can often spread throughout the attic within a matter of days or weeks.

Once mold and mildew have taken hold in the attic, they can be difficult to remove. Not only do they have a musty, unpleasant smell, but they can also cause a variety of health problems for those who are exposed to them. Mold and mildew can cause respiratory issues, such as allergies and asthma, and can also cause skin irritation and other allergic reactions.

In addition to the health risks posed by mold and mildew, they can also cause significant damage to the structure of your home. Over time, mold and mildew can eat away at the surfaces on which they grow, causing them to become weak and brittle. This can lead to serious damage to the roof and walls of your home, and can even cause the attic to become structurally unstable.

To prevent the growth of mold and mildew in the attic, it's important to address the underlying problem of condensation. By ensuring that the attic is properly insulated and well-ventilated, you can prevent moisture from building up on the surfaces of the roof and walls, and reduce the risk of mold and mildew growth. Additionally, it's important to regularly check the attic for signs of moisture and to address any moisture problems as soon as they are detected. By taking these steps, you can help to prevent the damaging effects of mold and mildew in your attic and protect the health and safety of your family.

Maine Attic Nightmares: Condensation, Mold, and Protecting Your Home

By Mattra Inc • August 18, 2025
That musty smell. The faint water stains on your attic ceiling. Maybe you’ve even spotted some unwelcome dark spots. If you’re a Maine homeowner, especially in our older homes, these could be signs of a serious problem brewing in your attic: condensation leading to mold growth. It's a more common issue than you might think, and it can have significant consequences for your home’s health and your wallet. Why is your Maine attic suddenly feeling like a rainforest? The culprit is often a perfect storm of factors we see frequently here at Mattra: a lack of proper air sealing and insufficient insulation. Think of your warm, humid indoor air rising into the colder attic space. Without proper air barriers, this warm, moisture-laden air sneaks through cracks and openings around wiring, plumbing, and light fixtures. Once this warm, moist air hits the cold surfaces in your uninsulated attic – like the roof sheathing – it cools rapidly. Just like water beading on a cold glass on a summer day, this cooling air releases its excess moisture in the form of condensation. And in a Maine winter, those surfaces stay cold for a long time! Several other common issues exacerbate this problem. That uninsulated attic hatch? It’s a direct pathway for warm, humid air to escape. An uninsulated chimney acts as another cold surface where condensation can form. And those bathroom and dryer vents that aren’t properly ducted to the outside? They’re pumping even more moisture directly into your attic – a recipe for disaster. So, what happens when all this condensation builds up? That’s where mold enters the picture. Mold spores are everywhere, both indoors and out. They thrive in damp, dark environments with organic materials to feed on – like the wood in your attic. Consistent condensation provides the perfect breeding ground. As mold grows, it doesn't just create unsightly stains and that telltale musty odor. It actively deteriorates the materials it grows on. Over time, mold can weaken the structural integrity of your roof sheathing and rafters, leading to costly repairs. It can also damage any stored items in your attic. Beyond the structural damage, mold growth can also impact your indoor air quality. Mold spores can become airborne and circulate throughout your home, potentially triggering allergic reactions, asthma symptoms, and other respiratory issues for you and your family. As a licensed vendor with Efficiency Maine , we understand the importance of a healthy home environment. The good news? These attic issues are often fixable! Proper air sealing prevents that warm, humid air from entering the attic in the first place. Adequate insulation helps maintain a more consistent temperature in the attic, reducing those cold surfaces where condensation forms. Insulating the attic hatch and chimney are crucial details often overlooked. And ensuring your bathroom and dryer vents are correctly ducted to the exterior is essential for removing excess moisture from your home. Addressing attic condensation and mold growth is an investment in your home's long-term health and your family's well-being. If you suspect you have an issue in your Maine attic, don't wait for the problem to worsen. Contact the experts at Mattra right here in Lewiston. We can assess your attic, identify the sources of condensation, and recommend the best solutions for mold remediation and preventing future problems through proper air sealing and insulation. Protecting your Maine home starts from the top down!

Blower Door Test

By Mattra Inc • April 3, 2025
Is Your Home Under-Insulated and Leaky? A Blower Door Test Can Tell You Many Maine homeowners don’t realize just how much money is flying out the window—literally. Drafty rooms, cold floors, and rising energy bills are often signs of poor insulation and hidden air leaks. But how do you know where your home is losing heat? A blower door test is one of the most effective tools to identify under-insulated and under-sealed areas in your home. Let’s explore how it works, why it matters, and what steps you can take to improve your home’s energy efficiency—and unlock valuable Efficiency Maine rebates in the process. What Is a Blower Door Test? A blower door test uses a powerful fan, mounted into an exterior doorway, to pull air out of your home and lower the indoor air pressure. This forces outside air in through any cracks or gaps in the building envelope. The result? A clear picture of where your home is leaking air. This test measures air changes per hour (ACH) and identifies weak points in insulation and air sealing. It helps assess how well your home keeps conditioned air in—and the outdoor elements out. An experienced technician can use this data to recommend targeted upgrades, saving you money on heating and cooling costs. How to Pass a Blower Door Test: Key Air Sealing Tips Passing a blower door test doesn’t require a full renovation—it’s about sealing the right places effectively. Here are the most common areas to focus on: 🪟 Windows and Doors Install weather stripping Use caulk or foam sealant around frames Check for gaps in thresholds or broken seals 🧱 Attics and Ceilings Seal around light fixtures and access hatches Insulate attic floors and rafters Use foam board or spray foam in hard-to-reach corners 🧰 Basements and Crawlspaces Seal rim joists with spray foam Insulate basement walls and floors Cover and seal crawlspace vents and doors 🧹 Floors and Walls Fill gaps around pipes, wiring, and ducts Seal baseboards and floor edges Add insulation in wall cavities if accessible By addressing these common problem areas, you can drastically improve your blower door test results and the overall comfort of your home. Why Blower Door Testing Matters Blower door tests aren’t just for code compliance—they’re a diagnostic tool to understand your home's efficiency. When performed by professionals, these tests: Reveal hidden air leaks Provide data for insulation and air sealing improvements Help reduce energy bills Improve indoor comfort and air quality Support home energy audit documentation During the test, technicians record the building's air leakage rate using calibrated gauges. Smoke pencils or infrared cameras may also be used to visualize the leaks. This ensures your energy upgrade dollars go exactly where they’re needed most. Mattra Handles It All—Testing, Air Sealing, and Insulation Ready to make your home more energy-efficient? Mattra offers professional blower door tests. At Mattra, we don’t just tell you what needs to be fixed—we do the work for you. As a licensed insulation and air sealing contractor, we can take your blower door test results and turn them into real improvements. From sealing drafty basements to upgrading attic insulation, our team handles every step in-house. That means fewer headaches for you—and faster results. Plus, we’ll help you navigate the Efficiency Maine rebate process , so you can maximize your savings without lifting a finger. One test. One team. One solution. Let Mattra make your home warmer, tighter, and more energy efficient—starting today.