How to…Create a Healthy and Sustainable Attic, Basement and Garage

Explore WLLW’s tips for turning these overlooked areas in your home into healthier, more efficient spaces.

Words Elissa Rose

Often overlooked spaces in our homes, the attic, basement and garage play essential roles in storage, utility and sometimes even living space. These areas, however, are often prone to hidden health and environmental concerns, from poor ventilation and dampness to exposure to harmful materials. In the latest addition to WLLW’s ‘How To…’ series, we explore how to transform these underused spaces into healthier, more sustainable parts of your home. Whether it’s tackling moisture in a finished basement, organizing a cluttered garage or improving air quality in the attic, thoughtful design can ensure these spaces contribute to the wellbeing of all those who live in your home.

Attic

The attic is often the least visited area of the home, primarily used for storage or as an unfinished space, yet its condition can have a significant impact on the health and energy efficiency of the entire house. Many attics, particularly in older homes, may still contain hazardous materials like asbestos. Frequently found in old insulation, pipe coverings or roof shingles, asbestos fibers can become airborne if disturbed during renovations or even through natural wear and tear. Exposure to these fibers poses serious health risks, including lung disease, asbestosis and mesothelioma. Before undertaking any attic updates, it’s essential to have the space inspected by a professional and, if necessary, arrange for safe removal of asbestos-containing materials.

Even modern insulation materials can carry health risks if not chosen carefully. Fiberglass insulation, for example, is widely used for its affordability and thermal properties, but its tiny glass fibers can irritate the skin, eyes and respiratory tract during installation and maintenance. Additionally, certain foam insulation products, such as spray polyurethane foam may off-gas Volatile Organic Compounds (VOCs) for weeks or months after application, contributing to poor indoor air quality and posing respiratory risks. Some US homes built before 1965 predate the code requirement for insulation and as such should be insulated with healthy materials for energy efficiency purposes.

To create a healthier attic environment, opt for ecologically-sound insulation materials like cellulose, made from recycled paper treated with non-toxic fire retardants, or sheep’s wool, which is naturally hypoallergenic, moisture-resistant and free from harmful chemicals. Some lesser known, yet effective insulation materials which are non-toxic include hempcrete (hemp and lime), aircrete (aerated foam concrete) or ThermaCork (expanded cork). These materials not only improve energy efficiency but also ensure a safer indoor environment for your family.

Proper ventilation is another crucial factor in maintaining a healthy attic. Without adequate airflow, heat and moisture can accumulate, creating conditions for mold growth and structural damage. Installing ridge vents, soffit vents or an attic fan can help regulate temperature and humidity levels, protecting both your home and your health.

If you’re using your attic as a storage area, avoid using particleboard shelving or other products that may emit VOCs. Instead, choose shelves made from solid wood or metal to reduce off-gassing. For those planning to convert the attic into a living space, incorporating low or no VOC paints, particularly mineral paints, natural flooring options and energy-efficient windows will create a safe and sustainable environment.

Basement

Basements often have unique challenges when it comes to maintaining good air quality, and these issues can significantly impact the rest of the home. The air quality of your house often starts in the basement because air from this space naturally moves upward through the ventilation system or via natural airflow. This means that buoyant pollutants originating in the basement, such as mold spores, allergens or chemicals, can spread to other areas, affecting the health of everyone in the household.

Basements are particularly prone to issues like excess humidity, which creates the perfect environment for mold growth as well as allergens like dust mites and pet dander. Research has shown that chemicals from paints, cleaning supplies or furnishings stored in the basement can further degrade air quality, while dampness and poor ventilation can lead to persistent odors, known as ‘basement smell’. Addressing these problems is crucial not only for maintaining a safe and healthy basement but for improving the air quality throughout your home.

Another health risk in basements is radon, a radioactive gas that can seep into homes through cracks in the foundation, floors or walls. Basements, being underground, are particularly susceptible to radon accumulation due to their proximity to the soil and limited ventilation. Produced from the natural decay of uranium in soil, rock and water, and is nearly impossible to detect without proper testing. Long-term exposure to radon is the second leading cause of lung cancer after smoking, according to the Environmental Protection Agency (EPA). Radon test kits are widely available, and professional testing services can provide detailed assessments. If radon levels are found to be above the EPA’s recommended action level of 4 picocuries per liter (pCi/L), mitigation systems should be installed. These typically involve a vent pipe and fan that redirect radon gas from beneath the foundation to the outside.

Additionally, older homes, especially those built before 1970, may contain asbestos, another hazardous material often found in insulation, flooring and pipe coverings. If disturbed, asbestos fibers can become airborne and pose serious respiratory risks, including lung disease, asbestosis and mesothelioma. Homeowners considering renovations or repairs in their basement should have the space professionally inspected for asbestos before beginning any work, as disturbing these materials can release harmful fibers into the air.

For finished basements, focus on using materials that resist moisture and enhance air quality. Cork products or ceramic tiles are excellent options for flooring, as they are durable, moisture-resistant and free from toxic chemicals. Many preexisting basements and newly constructed homes have poured concrete floors, for which minimal chemical treatments and coatings are preferable to maintain good indoor air quality. Innovations in concrete coatings include those made from gypsum and castor oil in place of epoxy. Furnishings should prioritize solid wood or metal construction to avoid off-gassing from materials like MDF or particleboard.

Basements are also commonly used for storage and often house essential home systems such as boilers, furnaces and water heaters, which require proper ventilation and a clutter-free space for safety. Storing flammable or chemical-laden materials near these systems can pose serious health and fire hazards. Ideally, these areas should remain clear, and any necessary storage should be well-organized, with sealed, airtight containers to prevent off-gassing and potential contamination of basement air.

To further improve air quality, consider installing a dehumidifier to maintain humidity levels below 60 percent, reducing the risk of mold and dust mites. Ventilation systems, such as heat recovery ventilators (HRVs) or energy-efficient air purifiers, can also be beneficial in ensuring that the basement remains a safe and comfortable part of your home.

Garage

Garages are versatile spaces, often doubling as storage areas, workshops or even home gyms. However, they can also be a source of pollutants, from vehicle emissions to hazardous chemicals stored improperly.

Begin by decluttering and organizing the space to reduce unnecessary exposure to harmful substances. Use sealed storage containers for items like paints, pesticides or cleaning supplies, and store them away from areas that connect directly to the house to minimize off-gassing. Installing shelving or wall-mounted racks made from sustainable materials can maximize space while reducing clutter. When the time comes to dispose of said chemicals and paints, it’s important to do so carefully to avoid contamination and a negative health and environmental impact. The EPA has tips and resources for the safe management of household hazardous waste.

If your garage is used for vehicle storage, ensure proper ventilation to prevent a buildup of fumes. A wall-mounted exhaust fan can effectively expel harmful gases. For homes with attached garages, sealing the door that connects the garage to the house with weatherstripping helps prevent pollutants from entering the living space.

Flooring upgrades can also enhance the garage’s safety and sustainability. As with basements, many garage floors have poured concrete and it’s important to consider the treatments and coatings used. Gypsum and castor oil coatings are available for garage floor use and will support healthy indoor air quality. If you’re converting the garage into a functional space such as a gym or workshop, consider adding insulation and energy-efficient lighting to make it more comfortable year-round.

Simple Strategies for a Healthier Attic, Basement and Garage

• Improve ventilation: Use fans, vents or dehumidifiers to maintain airflow and control moisture.
• Address dampness: Waterproof walls and floors, and ensure proper drainage around your home’s foundation.
• Seal and insulate: Apply environmentally-friendly insulation and seal cracks to prevent drafts and moisture intrusion.
• Test for radon: Especially in basements, regular testing and mitigation can reduce health risks.
• Declutter and organize: Use sealed containers and sustainable shelving to minimize exposure to hazardous materials.
• Upgrade flooring: Opt for moisture-resistant, low-VOC options such as cork, ceramic tiles or gypsum and castor oil coatings for the garage.
• Use non-toxic materials: Choose low-VOC paints, adhesives and furnishings made from solid wood or metal.
• Dispose of household hazardous waste carefully: Chemicals, paints and other solvents can cause environmental and physiological damage if not disposed of safely. Seek out hazardous waste facilities and collection services in your area.

Feature Image: Maison Lyle Interior Design