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Insulating Your Home: Understanding R-Value

Heat retention is important, a minimum R-value depends at least in part on where you live. If you live somewhere like Kansas City or St. Louis, you will need insulation with a higher R-value than people who live further south in states with milder winters.


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What Is R-Value?

The R-value is a measure of the thermal resistance for materials used in construction, for example, crawl space insulation. Higher R-values indicate better heat retention.

The R-value depends on factors such as the material used, the type of insulation, and the skill with which it is installed. Heat retention does not depend just on the thickness of the insulation but also the conductive properties of the material.

Types of Insulation

There are several options for insulating your home and they can be suitable for different situations.

Roll Insulation:

  • A traditional material for this type of insulation is fiberglass. It is typically fitted between studs, joists, and beams.


  • Cut out pieces of insulation that need to be fastened together tightly. Gaps between the batts can reduce heat retention. As with rolls, materials such as fiberglass, mineral wool, and natural fibers are common. As with rolls, it is often placed between joists and beams, under floors, in walls, and attics.

Blown-In Insulation:

  • Commonly used for attic floors and wall cavities, it often consists of small particles of fiber or expanded polystyrene beads.

Spray Foam Insulation:

  • This is different from blown-in insulation as it is applied using an aerosol spray and it tends to stick to surfaces more than blown-in insulation, it can be used on walls and other places such as attic floors. It can be particularly good for adding insulation around irregularly shaped areas and obstructions.

Rigid Foam:

  • This type of insulation comes in the form of large, pre-formed sheets that can be cut to size; it can incorporate reflective surfaces to increase heat retention. It has a high insulating value for relatively little thickness.  

The different types of insulation have different strengths and weaknesses, for example, fiberglass batts and rolls are easily available, but they are also easily damaged by humidity and dampness and have a relatively low R-value. Some rolls come with a facing layer that can help reduce moisture problems. Spray foam has a better R-value but if for some reason you wanted to replace it in the future, it is very difficult to remove. Rigid foam tends to have better heat retention and is more resilient than some materials like fiberglass even though it is thinner. 

How to Identify and Cover an Under-Insulated Area?

Unfortunately, your crawl space isn’t the only area you’ll need to worry about when it comes to insulation. Aside from it, there are a couple of other places around your home that either have no insulation or are under-insulated. Together, they allow cold air to flow through your home, dropping the temperature levels. You will, therefore, need to use more energy to bring the temperature to an adequate level.

Here are four areas you’ll need to keep an eye out for:

  • Crawl Space: Professionals should insulate the perimeter walls.
  • Basement: If you have an unfinished basement, you should inspect it. With the help of a professional use the R-value map for your area to determine what amount of insulation you’ll need.
  • Attic: Your attic needs better insulation than a crawl space or a basement. Hence, you should use a tape measure to determine its depth. It should be at least 19 inches deep. If it’s not, insulate over it with a high R-value product.
  • Floors: A badly insulated basement or crawl space is the reason why your rooms are colder than they should be. The professionals should measure your floor depth before they use insulation panels. This will make your home much more comfortable and cozy.
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Benefits of Insulation

Insulating your home provides several benefits beyond comfort. A properly insulated home provides:

  • Lower Utility Costs:

Insulating your home and areas like the crawl space ensures your living space stays warm in winter and cooler in summer, which reduces your cooling and heating costs.

  • Noise Reduction:

Insulation materials also make good soundproofing materials. They absorb unwanted noise and sound from your appliances or audio equipment, making your home quieter.

  • Enhance Energy Efficiency:

To make your home more energy-efficient, you need to insulate the floors and the exterior walls that separate the conditioned areas from the unconditioned ones. Insulation helps prevent heat leakage around openings and fixtures like door frames, windows, and the entry/exit points of pipes and wires.

  • Moisture Control:

Daily chores such as washing, bathing, and cooking release significant amounts of moisture to the indoor air. This vapor often gets trapped on the walls, leading to mold or mildew growth, which are a health concern. Insulation creates an effective barrier against such moisture.