Which Insulation Material Has the Highest R-Value?

Insulation is the key to efficient heating and cooling. Like a thermos or a drink cooler, insulation keeps heated and cooled air inside where it belongs. Insulating efficiency is measured in thermal resistance, or R-value, which conveys a material’s ability to resist heat transfer per inch of thickness. Higher R-values signify greater insulating power.

Why Is R-Value Important?

Knowing the insulation R-values throughout your home tells you whether you have enough insulation based on where you live. Inadequate insulation can lead to comfort problems and higher utility costs while achieving the recommended insulation levels makes your home more comfortable and energy-efficient.

Choose the Right Insulation for Your Home

The type and amount of insulation you need depends on several factors, including the local climate and what area you’re insulating. In general, the further north you live, the more insulation you need.

Referencing an insulation R-value chart can help with insulating your attic, walls, floors and crawl spaces adequately for your particular climate.

Insulation Types

  • Fiberglass insulation comes in batts, blankets, rolls and loose-fill, offering R-3.1 to R-4.3 per inch. Fiberglass is usually installed between wall studs, floor joists and ceiling rafters.
  • Cellulose insulation is available in loose-fill form and is rated between R-3.2 and R-3.9. It’s appropriate for attics and wall cavities.
  • Spray foam insulation comes in two forms — open-cell (R-3.5) and closed-cell (R-6.0 to R-6.5). Open-cell spray foam allows some air and moisture to travel through, while closed-cell insulation provides an air and vapor barrier.
  • Rigid foam board insulation is available in numerous materials, including polystyrene (R-3.8 to R-5.0), polyurethane (R-5.5 to R-6.5) and polyisocyanurate (R-5.6 to R-8.0). Rigid foam is typically reserved for foundations and basement walls.

Insulation FAQs

How does insulation work?

To understand how insulation works, it helps to understand the three types of heat flow:

  • Conduction is the flow of heat through a material. 
  • Convection describes how heat circulates through liquids and gases.
  • Radiation is the movement of heat in a straight line through anything solid in its path.

Regardless of the mechanism, heat flows toward cooler areas until the temperature equalizes. In the winter, heat flows from the conditioned living space to adjacent unheated areas, such as the attic, garage, crawl space and outdoors. 

Insulation aims to slow the heat transfer that results in winter heat loss and summer heat gain. Most insulation materials, like cellulose and fiberglass, resist conductive and convective heat flow. Radiant barriers and reflective insulation reduce radiant heat flow.

What R-value do I need?

For the most cost-effective results, follow the recommended insulation R-values for your region:

  • North/Northeast: Attic R-49 – R-60 | 2×4 walls R-13 – R-15 | 2×6 walls R-19 – R-21 | floors & crawl spaces R-25 – R-30
  • West/Midwest: Attic R-38 – R-60 | 2×4 walls R-13 – R-15 | 2×6 walls R-19 – R-21 | floors & crawl spaces R-25 – R-30
  • South/Southeast: Attic R-30 – R-60 | 2×4 walls R-13 – R-15 | 2×6 walls R-19 – R-21 | floors R-25 | crawl spaces R-19 – R-25

How do I know what insulation type I need?

Once you know the ideal R-value for different parts of your home based on where you live, choosing the right type of insulation comes down to the application and budget. Talk to an insulation contractor at Mooney & Moses to help you decide between cellulose, fiberglass, spray foam and rigid foam board.

Contact Insulation Installers in Cincinnati, OH

Whether you know what insulation you want or you’re looking for personalized tips, the insulation experts at Mooney & Moses can help. We’ll make recommendations based on your needs and budget and install your preferred insulation quickly and affordably.

With over 65 years of experience, you know you’re in good hands with Mooney & Moses!

Call 513-341-8918 today or contact us online to request insulation services in the Cincinnati area.

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