Home Insulation - The Basics: What You Need to Know About Insulating Your Home
When insulating or upgrading the insulation in your home, there’s several things to consider. You’ll need to know what the code requirements are & consider what DOE and Energy Star recommends, understand your goals for the project, and know your options for insulation materials.
Virginia Insulation Code Requirements & DOE Recommendations
|
Area of Home |
Code Requirement |
DOE Recommendation |
|
Exterior Walls |
R-15 |
R-19 |
|
Crawl Space Floor |
R-19 |
R-19* |
|
Crawl Space Walls |
R-10 |
R-19 |
|
Basement Ceiling |
R-19 |
R-19* |
|
Basement Walls |
R-10 |
R-15 |
|
Attic Rafters/Slopes |
R-49 |
R-49 – R-60 |
|
Attic Floor |
R-49 |
R-49 – R-60 |
|
Vaulted/Cathedral Ceilings |
R-49 |
R-49 |
* The DOE Recommendation for crawl space and basement ceiling insulation varies by application not by R-value.
What is R-Value?
R-value is how we measure an insulation material’s resistance to heat transfer. The higher the R-value, the more effective of an insulator the material is. A material with an R-value of 11 allows heat to pass through more easily than an R-38.
To determine a material’s R-value, we divide the thickness of a material (in meters) by its thermal conductivity (k-value).
Determining Your Insulation Goals
When you’re insulating your home, you need to assess what factors are important to you. To help you determine this, you might also consider what symptoms you are experiencing in your home.
Common Symptoms homeowners experience include:
- Cold Floors
- Uneven temperatures
- Frequently running HVAC
- Rooms too hot/cold
- Drafts
- High energy bills
- The need for space heaters or box fans
Your goals Might Include:
- Warmer floors
- Even temperatures throughout the home
- Reduce wear and tear on HVAC units.
- Make rooms more comfortable.
- Reduce drafts.
- Lower energy bills
- Eliminate the need for fans and heaters.
Your symptoms and goals help determine where to start when improving the insulation in your home. When the concern is energy efficiency, we often start at the top of your home in the attic and assess the condition of insulation and air-leakage in this space. However, if you’re more concerned about cold floors and drafts, we might look at the crawl space or basement first.
It’s key to look at the home as a complete system to evaluate the cause of your symptoms so that you can achieve your goals.
Insulation materials
There’s a vast variety of insulation materials on the market to choose from and each has its own pros and cons. When selecting a material, you might consider its R-value per inch, sustainability, and application.
For example, Rockwool insulation is the best option if you need to insulate your chimney chase because it’s non-flammable. When insulating your attic floor, cellulose insulation is a great choice because it has a high R-value per inch plus and is also fire resistant.
Here’s a quick snapshot of common insulation materials you’ll see when considering insulation for your home.
|
Material |
R-Value per Inch |
Common Applications |
|
Batt Fiberglass (Faced & Un-faced) |
R-2.9 – R-3.8 |
Exterior & Interior Walls, Attic floor, Basement Ceiling, Crawl Space Ceiling, Garage Walls |
|
Blown-in Fiberglass |
R-2.2 – R-2.7 |
Exterior & Interior Walls, Attic floor |
|
Cellulose Insulation |
R-3.8 |
Exterior & Interior Walls, Attic floor, Attic Slopes |
|
Open Cell Spray Foam |
R-3.6 |
Exterior Walls, Attic slopes, Crawl Space & Basement Walls |
|
Closed Cell Spray Foam |
R-7 |
Exterior Walls, Attic Slopes, Attic Floor, Crawl Space Floor, Crawl Space Walls, Basement Floor, Basement Walls, Garage Walls |
|
Rockwool Insulation |
R-3 – R-3.3 |
Chimney Chase, Around Can Lights, |
|
Rigid Foam board Insulation |
R-6.2 |
Attic Slopes, Attic Storage Decking, Crawl Space Walls, Basement Walls |
|
Mineral Wool |
R-4 |
Exterior walls, basements, heated crawl spaces |
|
|
|
|
While these materials can all be used in a variety of places, some are better suited in different applications and environments than others. It’s important to remember that your goals for your project and the existing condition of your home play a factor in what application and approach is going to be the right option for you and your home.
For a free home insulation inspection and estimate, call The Drying Company at 1-757-566-8622 or 1-757-566-8622. Our Advisors will listen to your concerns and goals, do a full assessment of your home, and help you develop the right solution with the right materials to achieve your goals.
