Everything You Need to Know About Blown-In Insulation: Materials, Methods, and Costs
Keeping your home comfortable and energy-efficient is essential, and blown-in insulation could be the solution you’re looking for. If your home is older, it may not have enough insulation, especially compared to the standards of modern building codes. Blown-in insulation is a great option for improving your home’s comfort while reducing energy bills. It involves blowing small particles of material into your walls or attic through a hose, filling up all those little gaps where air might escape. Let’s dive into the details to see if this method is the right fit for you.
1. Blown-In Insulation: A Quick and Easy Way to Fill Wall and Ceiling Gaps
Unlike batt insulation, which is placed between wall studs or ceiling joists during construction, blown-in insulation can be added later without ripping apart your walls. Batt insulation installation in existing homes is tricky because it requires removing drywall, which is expensive, messy, and time-consuming. In contrast, blown-in insulation can be installed quickly and cost-effectively, making it a great choice for retrofitting older homes.
One big advantage of blown-in insulation is how it settles into small cracks and spaces that batt insulation might miss, effectively blocking drafts and keeping your home warmer in the winter and cooler in the summer. Plus, it helps reduce noise from outside, acting like a soundproofing blanket.
2. Blown-In Wall Insulation: Some Aesthetic and Performance Considerations
Installing blown-in insulation in walls involves drilling holes in the exterior and filling the space between studs. After the material is blown in, the holes are sealed with plugs that match your home’s siding. However, on materials like brick or stucco, the plugs can sometimes be a little noticeable.
There are a few performance challenges as well. Objects inside your walls, like pipes or outlet boxes, can sometimes prevent the insulation from fully filling the space, creating gaps. Over time, the insulation may also settle slightly, especially in wall cavities, leaving a small uninsulated area at the top. While this doesn’t drastically affect the overall insulation, it’s worth considering.
3. Types of Blown-In Insulation: Which One Is Right for You?
Blown-in insulation comes in three common types—fiberglass, cellulose, and rock wool. Each has its strengths and weaknesses, so let’s take a closer look.
- Fiberglass: This insulation is made from glass that’s been melted down and spun into fine fibers. It’s light, easy to install, and provides an average R-value (a measure of insulation effectiveness) of R-5 per inch. To match the insulating power of R-19 batt insulation, you’ll need about 7.5 inches of fiberglass blown-in insulation. It’s a popular choice for attics and walls.
- Cellulose: Eco-conscious homeowners love cellulose because it’s made from recycled paper products. It’s treated to resist mold and fire and provides an R-value of around 3.7 per inch. However, if it gets wet, it can lose its effectiveness by becoming soggy and compacted. For R-19 insulation, you’d need around five inches of cellulose.
- Rock Wool: Made from the byproduct of industrial furnaces, rock wool (or mineral wool) has a thermal rating of R-3 per inch. It’s particularly fire-resistant, making it a good choice for areas prone to higher fire risks, such as between a garage and a house. It’s also moisture-resistant, lasting up to 100 years in optimal conditions.
4. Blown-In Insulation: DIY or Hire a Pro?
For those interested in DIY projects, adding blown-in insulation to your attic can be a manageable task, but adding it to walls is best left to the pros. Installing insulation in walls requires drilling and dealing with potential wiring or pipes behind your walls, which can get tricky.
In the attic, you can rent a blower from home improvement stores (sometimes for free if you buy a certain amount of insulation). You’ll need someone to help load the insulation into the machine while you distribute it in the attic. Protective gear like gloves, masks, and goggles is a must, as the process can get messy.
One safety tip: Never stand directly on joists while working in the attic, as you could fall through the ceiling below. Use plywood as a stable platform while moving around. Be mindful of electrical boxes and recessed lighting, as they can overheat if insulation is packed too tightly around them.
5. How Long Does Blown-In Insulation Last?
The lifespan of blown-in insulation depends on the material and the conditions in your home. Fiberglass can last 80 to 100 years if installed correctly, while cellulose typically lasts around 20 to 30 years due to its susceptibility to moisture. Rock wool, known for its durability, can last a lifetime. It’s a good idea to check your insulation after about 15 years, especially in areas prone to water damage, to ensure it’s still in good shape.
6. Can You Remove Blown-In Insulation?
If you need to remove blown-in insulation, whether due to renovations or damage, you can tackle this as a DIY project in the attic. Contractors use industrial vacuums, but you can use a high-powered wet/dry vacuum if you’re up for the challenge. Be sure to wear protective clothing, including a respirator, as the insulation fibers can irritate your skin and lungs.
For wall insulation, it’s best to hire a professional, as they have the tools and experience to remove it without damaging your walls or electrical systems.
7. What’s the Cost?
The cost of blown-in insulation varies depending on the material and whether you hire a professional. On average, materials like fiberglass and cellulose can range from $0.50 to $2.30 per square foot, while rock wool is a bit pricier. Labor typically costs between $40 and $70 per hour, but you can cut costs by doing the attic work yourself.
Attics generally require more insulation (R-30 to R-60) than walls (R-13 to R-23), so insulating an attic is often more expensive due to the larger surface area and higher R-values needed. Hiring a local insulation expert can help you get multiple quotes to find the best option for your home and budget.
Final Thoughts
Blown-in insulation is a flexible and efficient way to upgrade your home’s insulation, especially for older homes. It’s less invasive than traditional insulation methods and can help keep your home cozy and energy bills low. Whether you choose to do it yourself or hire a professional, blown-in insulation is a smart investment in your home’s comfort and long-term savings.
