Insulation Installation | DIY Home Insulation
Energy & Home Insulation
Proper insulation is a homeowner's best defense against high energy bills. It doesn't matter what forms of climate control you use, if your home is poorly insulated, you'll spend more to keep it warm in winter and cool in summer.
As a Realtor, I hear quite a bit about what people spend on their utility bills. I've seen similarly sized homes with two occupants that cost more to heat than a nearby family of five spends on their utility bills! Perhaps you're independently wealthy and don't mind tossing a thousand or two dollars out to those kind-hearted gas and electric companies, but if you'd rather splurge on something for yourself, keep reading!
Insulating a home is an easy, affordable way to make your lifestyle more comfortable, and can often be done by a home owner in a very short time. Take a look at how easy it is to become a do-it-yourselfer at improving your home's weather-tightness.
How much does your household spend for natural gas, propane, and/or electric bills each month?See results without voting
Pinpointing Problem Areas
Many local utility companies offer free or low-cost energy consultations. If yours doesn't, you can use a match or lighted incense near door frames, windows, and chimneys to look for obvious problem areas, but you might have to hire a professional home inspector if you want to get maximum information about energy inefficiencies in your home.
What is Insulation?
When it comes to home construction, the word insulation can refer to anything that slows the transfer of some sort of energy. Although this article is focused on slowing the transfer of heat energy, it's also possible to insulate against sound and electricity, too.
Without getting all science-y or math-y on you, probably because I am not a scientist, I'll stick with the simplest description I can think of that will explain important basics:
1. When it comes to temperature, there is no such thing as "cold." We only measure units of heat, or lack of heat.
2. Every object has energy. Heat is also a type of energy. When heat affects an object, it's not quite accurate to say that the object "contains" heat. Instead, this thermal energy is changing the object's own energy in some way.
3. For our purposes, it's sufficient to say that the heat energy is transferring from one substance to another - from the ambient air in a room, through objects, and then to the outdoors (or vice versa.)
4. A house that resists the transfer of this heat energy is more efficient and weather-tight than one that has less resistance. Insulation slows the transfer of the heat energy, creating this kind of resistance.
5. Resistance to heat loss is how an insulation's effectiveness is measured. This is known as its R-factor. A higher number means higher resistance and more energy efficiency.
Here are some approximate R-values for materials you're familiar with already:
Thermal Resistance of Common Substances
Less than 0.15
Bale of straw
R-3 to R-4
Home Insulation - Materials and Cost
Before you calculate the cost of your specific project, you should recognize that certain factors may influence your decision:
- Ease of application
- How much product is needed to obtain a certain R-Value
- How quickly your new insulation will deteriorate
- Environmental factors
DIY Insulation Options
Open Cell Polyurethane Spray Foam
Around doors, windows, cavities around pipes
R-3.5 / R-3.6
$1.20 per sq. ft.
"Quick fix" for some problems
Moisture can penetrate. Chemicals released when applying/curing can trigger breathing problems.
Loose Fill Cellulose
Attic floors, some ceilings*, wall cavities
R 3.2- R 3.8 per sq. in.
$0.31 per cubic foot
Made with recycled paper and flame retardant. Few health concerns. May discourage some pests.
Loses up to 20% of its effectiveness over time.
Loose Fill Fiberglass
R- 2.2 - R 2.7 per sq. in.
$0.31 per cubic foot
Some recycled content. Lightweight.
May contain carcinogens. Fiberglass can cause health problems if fiber dust is inhaled. May require renting a blower. Loses up to 50% effectiveness in very cold weather. (Consider using blankets in conjunction.)
Walls, around pipes
R 3.5 - R-4
$0.90 per sq. ft.
Some recycled content. Easy to use rolls. Not "itchy." May contain a fire retardant that deters some pests.
Walls, floors, attics
R-4 to R-5
$0.60 per sq. ft.
High recycled content. Increased fire resistance. Easy installation (staple-free). Not "itchy."
Retains moisture (can promote mold growth.) Contains silicates that can cause cancer if inhaled.
Metal roofs, garage doors, water heater**
R-3 to R-10
Easy to use. Environmentally safer. Noise/light reduction when used on windows.
Can trap moisture.
Using Loose Fill & Batts in Attics
Attic and Crawl Space Insulation
R-19 value for walls and floors. Note that paper side goes next to the floor or wall so that the product doesn't hold moisture! Product is formaldehyde free. Approx. 118 ft. per package.
Great Choice for Garage Insulation
Extremely cost effective and easy to use. Product width is ideal for garage door panels and inside metal roofs or sheds. Especially good at keeping heat out in hot climates. Bonus use: Add suction cups to create window shades for use when needed.
Professional Insulation Installation & More DIY
There are other types of insulation I have not covered in this article because they're typically not DIY projects. If you are remodeling or selecting insulation for a new construction, chances are you've already been working with a contractor who has a crew for more complex installations.
You'll probably still be interested in inquiring about the R-value of insulating materials that will be used, and whether it will deteriorate over time. For example, structural insulated panels (SIPs) may be made from a variety of materials and can have a wide range of resistance that certainly influences cost.
You may also have noticed I have primarily addressed insulation areas that have a significant impact on energy bills and can legitimately be considered DIY projects. Of course, there are also quick fixes that can save money even though they don't provide permanent solutions to heat transfer:
- Drafts at doors
- Drafts in window frames
- Glass window panes that are not energy efficient
You'll find temporary solutions to these products here:
This product is rated well, and it's effective, but I encourage having a friend help when you apply it. When I did mine without help, it did not look as nice as I'd hoped!
Easy to use product if you don't want to apply weather stripping to a door. I haven't used this myself, but the reviews are positive and I'm pretty sure it works better than those "door draft stoppers" that I've wasted money on in the past!
Ready? Great! Insulate!
For up to date information about available tax credits and to calculate how many rolls of insulation you'll need, you can check out the Owens-Corning calculator. You can use the general project tool or select an unfinished attic.
Remember, if you use rolled insulation that has a moisture barrier on one side, you must put the paper/waxy surface next to the surface you are insulating, and the fiber material should be left exposed to the air. When DIYers install it incorrectly (something I've seen a few times in houses I've sold!) it can trap moisture against the floor joists, subfloor, or roofing materials, promoting mold growth. If you discover insulation that has already been improperly installed, inspectors suggest cutting the vapor barrier open to prevent moisture from condensation turning into a problem area later.
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