Uneven temperatures throughout a home, with some rooms feeling too hot while others are too cold, are almost always caused by uncontrolled air movement. Air leaks in the building envelope allow conditioned air to escape and outside air to enter, forcing your HVAC system to work harder without ever achieving a stable indoor climate. Spray foam insulation directly solves this problem by creating an airtight seal that stops these leaks, resulting in a consistently comfortable temperature in every room.
This guide explains the connection between air leakage and temperature imbalance, details how spray foam works, and outlines key considerations for homeowners in the Southaven area. The information is based on extensive field experience addressing comfort and efficiency issues in Mississippi’s mixed-humid climate.
Many people blame their HVAC system or old windows for inconsistent temperatures, but the primary cause is typically air infiltration. This is the process of outside air entering the house through countless small cracks, gaps, and openings. In the summer, hot, humid air seeps in, while in the winter, warm air rises and escapes through the attic, pulling cold air in through the lower levels of the home.
Common air leakage points include:
In Southaven, high humidity magnifies the problem. Humid air carries more thermal energy, so when it leaks into your home during the summer, it makes rooms feel significantly warmer and stickier. Traditional insulation like fiberglass batts or blown-in cellulose can slow heat transfer, but they don’t stop air movement, leaving these gaps open.
Spray Polyurethane Foam (SPF) is applied as a liquid that expands rapidly to fill every cavity, no matter how small or irregularly shaped. This expansion process creates a continuous, rigid barrier that adheres directly to the building materials. By sealing gaps that other insulation types can’t, spray foam effectively stops air infiltration and exfiltration.
This monolithic seal is what makes spray foam so effective at balancing temperatures. It prevents drafts and stops the exchange of conditioned indoor air with unconditioned outdoor air. According to the U.S. Department of Energy, reducing the amount of air that leaks in and out of your home is a cost-effective way to cut heating and cooling costs, improve durability, and increase comfort. The U.S. Environmental Protection Agency (EPA) estimates that homeowners can save an average of 15% on heating and cooling costs by air sealing their homes and adding insulation. When your home’s thermal envelope is properly sealed, your HVAC system can distribute air evenly without fighting constant leaks.
There are two main types of spray foam, and the choice between them depends on the application, as each has different properties suited for specific goals like moisture control or structural support.
| Feature | Open-Cell Spray Foam | Closed-Cell Spray Foam |
|---|---|---|
| Density | Low (approx. 0.5 lbs/cubic foot) | High (approx. 2.0 lbs/cubic foot) |
| R-Value | ~R-3.6 to R-3.9 per inch | ~R-6.0 to R-7.0 per inch |
| Air Barrier | Yes | Yes |
| Vapor Permeability | Permeable (allows water vapor to pass) | Impermeable (blocks water vapor) |
| Structure | Soft, flexible, and spongy | Rigid and dense |
| Primary Use Case | Attics, interior walls, sound dampening | Crawl spaces, foundation walls, roofs |
For homes in the Southaven area, closed-cell foam is an excellent choice for crawl spaces and basement walls because it acts as a vapor barrier, preventing ground moisture from entering the home. Open-cell foam is often used on the underside of roof decks in attics, as it provides a great air seal and has sound-dampening qualities. In some cases, a hybrid system can also be effective by applying a thin layer of closed-cell foam to create a vapor barrier, then filling the rest of the cavity with open-cell foam for a more budget-friendly approach.
Before installing spray foam, it’s important to evaluate a few factors to ensure it’s the right solution for your home.
Creating a very airtight home is great for energy efficiency, but it also means that pollutants, moisture, and stale air can get trapped inside. A report from the Environmental Protection Agency suggests that homes with low natural ventilation may need mechanical systems to ensure healthy air exchange. A balanced ventilation system like an Energy Recovery Ventilator (ERV) is often recommended for tightly sealed homes in humid climates to bring in fresh air without the excess moisture.
The performance of spray foam is highly dependent on the quality of the installation. The chemicals must be mixed at the correct temperature and ratio, and the foam must be applied at the proper thickness. An inexperienced installer can create a poor air seal or, worse, cause damage. Always verify an installer’s credentials and experience.
Spray foam insulation has a higher initial cost than traditional insulation materials. However, its ability to reduce energy consumption provides savings over time. The improved comfort, better indoor air quality, and increased structural stability (with closed-cell foam) also add significant long-term value to the property.
Ultimately, resolving uneven temperatures comes down to controlling air movement within the building envelope. By creating a complete air seal, spray foam insulation stops the leaks that cause drafts, hot spots, and cold spots. This results in a more stable, comfortable, and energy-efficient living space. Before deciding on a solution, it’s best to evaluate your home’s specific trouble spots and consider your long-term goals for comfort and utility savings.
The first step to solving temperature imbalances is identifying the source of the problem. A thorough home performance assessment can pinpoint air leakage points and determine the most effective insulation strategy. To schedule a detailed evaluation of your home, contact Armored Insulation at (270) 727-5566 or send a message to [email protected] to discuss your home’s specific needs.
Yes, spray foam is commonly used for retrofitting. Installers can apply it in open cavities like attics, crawl spaces, and rim joists. For enclosed walls, a different type of injectable foam can be used, or drywall can be removed for application.
Modern spray foam products are formulated to be safe once cured. During installation, the area must be properly ventilated and occupied only by trained professionals wearing personal protective equipment. Homeowners can typically re-enter the home within 24 hours after the installation is complete. For added peace of mind, ask your installer for the Safety Data Sheet (SDS) for the specific product being used, as this document provides detailed information on curing times and safety measures.
High humidity makes moisture management a top priority. Closed-cell spray foam is an ideal choice for below-grade applications like crawl spaces because it is a certified vapor retarder, blocking moisture from wicking into the home’s structure and preventing mold growth.
Yes. Due to its dense, air-sealing nature, spray foam significantly reduces airborne sound transmission. Open-cell foam, in particular, has excellent sound-absorbing properties, making it a great option for walls between rooms or to quiet noise from busy streets.
R-value measures an insulation’s resistance to conductive heat flow. Data from the International Association of Certified Home Inspectors (InterNACHI) shows that closed-cell spray foam has one of the highest R-values per inch available, ranging from R-6 to R-7. This is nearly double that of fiberglass batts, which typically offer around R-2.9 to R-3.8 per inch.
Spray foam is an inert material that does not sag, settle, or degrade over time like some other insulation types. When installed properly, it should last for the life of the building, providing consistent performance without needing to be replaced.