What is the Best Insulation?
Believe it or not, there actually is an answer to the question, "What is the best insulation?" But the answer can not be found in the sea of misinformation provided by the insulation manufacturers. Instead, the unbiased answer comes from the research of hundreds of scientists.
Over the past 30 years, building scientists have been busy studying how our homes use and lose energy. They've built walls and model homes and put them inside of enormous chambers to study the effects of wind, cold and heat. The results of their research create an opportunity for millions of Americans to save hundreds of dollars every year on their energy costs.
One of their most important discoveries is that our homes leak like a sieve. Air passes right through our homes taking the heat or air conditioning with it. According to the U.S. Dept. of Energy, the average home loses over 30% of its heat or air conditioning through gaps, cracks and holes. On a cold, windy winter day you can feel the air blowing through your home in the form of drafts.
The Best Insulation creates an Air Tight Seal
The secret to saving money on your energy bills is simple. Keep the air you've paid to heat or cool inside of your home.
This may sound simple, but there are only a few ways to do this and only one kind of insulation that creates an air-tight seal in your floors, walls and ceilings. This insulation is known as spray foam insulation and it is as revolutionary as insulation gets.
Spray Foam Insulation is the BEST Insulation
Spray foam insulation is a combination of chemicals which are sprayed out of a machine through a hose. The spray foam chemicals mix together at the tip of the hose creating a thick paint-like goo that sticks to anything it touches including wires, pipes and ducts.
Within seconds, the foam begins to expand trapping a gas inside billions of tiny bubbles. As the foam expands, it forms a continuous even layer of insulation and creates an air tight seal. Exactly what insulation needs to do, right?
The Best Insulation comes in Two Forms
Open Cell and Closed Cell
The first thing you need to know is there are two different types of spray foam with different characteristics and applications.
Open-Cell Spray Foam
The cheapest spray foam option is known as open-cell. So called because the bubbles inside of the foam never completely close. As the foam expands, air gets trapped in between the broken bubbles. This divides the space into billions of tiny air pockets that slow down heat as it tries to pass through. Open-cell spray foam is a much softer type of foam because of the broken bubbles. These bubbles allow water to pass through them, which can be good or bad depending on the application. Although open-cell spray foam does a great job at filling in and around wires, pipes and other obstacles, it's insulating power is not all that spectacular: R-3.5 per inch.
Closed-Cell Spray Foam
The bubbles or cells in closed-cell spray foam are closed and tightly packed together. This makes
closed-cell spray foam much denser and stronger than open-cell spray foam. It will not absorb water or allow air to pass through it. This is because the bubbles in closed-cell foam are filled with a gas making them much smaller and a better insulator. Closed-cell spray foam tops the charts in insulating power with an impressive average of R-7 per inch.
The Best Insulation isn't Cheap
It's really important to know the difference between the various spray foams. Mainly because open-cell is much less expensive. If you're contractor listed the density of the foam instead of specifying open-cell or closed-cell. Open-cell foams usually have a density of about 0.5 lb./ft and closed-cell foams are usually 1.75lb/ft and higher. So if you're thinking about having spray foam installed in your home, make sure you're comparing apples to apples on the contractor's bids.
If price is an issue, your contractor may suggest combining both types of spray foam to help you reach your budget. To do this, they start out by spraying the thermal boundary of your home with a closed-cell spray foam to create an air-tight shell with a vapor barrier. Then follow up with open-cell spray foam to fill in the space between the framing. This is a great option for a limited budget because you get the best of both worlds. An air-tight home with a high level of r-value.
DIY Spray Foam Insulation
Yes, it is possible to do-it-yourself. Disposable kits that come with everything you need to safely install spray foam insulation are the newest craze in insulation. They are great for small jobs where keeping the wind and moisture out are crucial. They are also great for a technique known as Flash and Batt.
Flash and Batt
Using the Flash and Batt technique, you begin by spraying the wall with a 1" layer of closed-cell spray foam. This creates an air tight wall cavity with a vapor barrier. Next, you fill the rest of the space with fiberglass batts or rolls. The theory here is to increase the insulating power of the wall and to overcome one of fiberglass insulation's greatest weaknesses, convective heat loss. Convective heat loss is due to air moving through the walls, like when the wind blows and pushes cold air into your home. The closed-cell foam stops the air and helps the fiberglass insulation work properly.