Insulation FAQ

DFW Insulation Contractors helps connect property owners with local insulation providers throughout the Dallas-Fort Worth metroplex and surrounding North Texas communities.

Service areas may include Dallas, Fort Worth, Grapevine, Southlake, Colleyville, Flower Mound, Keller, Coppell, Mansfield, Arlington, Irving, Grand Prairie, Plano, Frisco, McKinney, Allen, Richardson, Lewisville, Denton, Roanoke, Trophy Club, Westlake, North Richland Hills, Hurst, Euless, Bedford, Burleson, Midlothian, Waxahachie, Weatherford, Aledo, and nearby areas.

If you are located in or near DFW, you can request a quote for spray foam insulation, attic insulation, blown-in insulation, radiant barrier installation, insulation removal, soundproofing insulation, or commercial insulation services.

R-value measures how well insulation resists heat flow. The higher the R-value, the greater the insulating power.

In simple terms, R-value helps describe how effectively insulation slows heat from moving through a wall, attic, roofline, floor, or other building assembly.

In the summer, insulation helps slow heat from moving from a hot attic or exterior area into the living space. In the winter, insulation helps slow heat from escaping the conditioned space into colder areas.

R-value does not create heating or cooling. It simply helps slow heat transfer so the building can be more comfortable and efficient.

Insulation is usually rated by R-value per inch and by the total installed R-value.

Different insulation types have different R-values per inch. For example, six inches of one insulation material may have a different R-value than six inches of another material.

Typical R-value ranges include:

Fiberglass batts: about R-2.9 to R-3.8 per inch

Blown-in fiberglass: about R-2.2 to R-2.7 per inch

Blown-in cellulose: about R-3.2 to R-3.8 per inch

Mineral wool / rock wool: about R-3.0 to R-4.2 per inch

Open-cell spray foam: about R-3.5 to R-3.9 per inch

Closed-cell spray foam: about R-6.0 to R-7.0 per inch

Rigid foam board: about R-4.0 to R-6.5 per inch

Radiant barrier: not rated like traditional insulation because it is designed to reflect radiant heat rather than resist conductive heat flow.

These numbers are general ranges. Actual R-values depend on the specific product, thickness, density, installation quality, compression, moisture, and manufacturer specifications.

The right attic R-value depends on the home, existing insulation, attic design, local code requirements, and performance goals.

Many homeowners in North Texas compare attic insulation targets such as R-38, R-49, or higher, depending on the age of the home, current insulation level, and project goals. If your attic insulation is thin, uneven, compressed, damaged, or below the top of the ceiling joists, it may be worth having the attic evaluated.

A local insulation provider can inspect the attic and help determine whether you need additional blown-in insulation, spray foam, air sealing, radiant barrier, insulation removal, or another approach.

A higher R-value generally means better resistance to conductive heat flow, but R-value is not the only factor that matters.

Insulation performance can also be affected by:

• Air leaks

• Gaps in insulation

• Compression

• Moisture

• Poor installation

• Duct leakage

• Attic ventilation

• HVAC system performance

• Sun exposure

• Building design

For example, an attic with a high R-value but major air leaks may still perform poorly. Likewise, insulation that is compressed, wet, or uneven may not perform close to its rated value.

The best results usually come from combining the right R-value with proper installation, air sealing, ventilation, and moisture control.

There is no single best insulation for every home. The right choice depends on the home’s construction, attic condition, budget, comfort issues, and performance goals.

Common options include:

Blown-in insulation for attic upgrades and adding coverage over existing insulation

Spray foam insulation for air sealing, rooflines, metal buildings, and higher-performance projects

Fiberglass batts for walls, floors, and some framed cavities

Cellulose insulation for dense attic coverage and retrofit applications

Radiant barrier for reducing radiant heat transfer in attic spaces

Insulation removal when old insulation is damaged, contaminated, or no longer performing well

In many DFW homes, attic insulation is one of the first areas to evaluate because attic heat can have a major effect on comfort.

Open-cell spray foam is lighter, softer, and expands more after application. It is often used in residential attics, rooflines, and interior cavities. It provides a lower R-value per inch than closed-cell foam but can still help reduce air movement when properly installed.

Closed-cell spray foam is denser, harder, and provides a higher R-value per inch. It is often used in metal buildings, commercial spaces, exterior walls, and areas where higher R-value in less space is important.

Open-cell foam is usually less expensive than closed-cell foam. Closed-cell foam usually costs more but may provide stronger thermal resistance, rigidity, and moisture resistance depending on the application.

The better choice depends on the building, budget, target R-value, moisture conditions, and installation location.

Spray foam and fiberglass work differently, so the better choice depends on the project.

Spray foam may be preferred when air sealing, higher performance, or insulating an irregular space is important. It can be useful in attics, rooflines, metal buildings, shops, and certain commercial applications.

Fiberglass may be preferred when cost is a major factor or when adding attic insulation over existing material. Blown-in fiberglass can be a practical option for many attic upgrades.

In some homes, the best approach may not be spray foam throughout the attic. It may be air sealing plus blown-in insulation, radiant barrier, insulation removal, or another combination.

A radiant barrier is a reflective material installed in an attic to help reduce radiant heat transfer. It is often installed along roof rafters, roof decking, or attic surfaces where it can reflect radiant heat.

Radiant barrier is different from traditional insulation. Traditional insulation is rated by R-value and slows conductive heat flow. Radiant barrier is designed to reflect radiant heat.

In hot climates like North Texas, radiant barrier may be considered as part of an attic heat-reduction strategy. It is often used along with attic insulation, not necessarily as a replacement for it.

No. Radiant barrier and traditional insulation are different.

Traditional insulation, such as fiberglass, cellulose, or spray foam, is rated by R-value and helps resist heat flow.

Radiant barrier reflects radiant heat and is not usually rated the same way as traditional insulation.

A radiant barrier may help reduce attic heat gain in certain homes, but it does not replace the need for proper attic insulation. The best solution may include both attic insulation and radiant barrier depending on the home.

Not always. In some cases, new blown-in insulation can be added over existing attic insulation if the current material is dry, clean, and in acceptable condition.

However, insulation removal may be recommended if the existing insulation is:

• Wet

• Moldy

• Damaged by rodents

• Contaminated

• Heavily compressed

• Filled with debris

• Affected by smoke or odor

• Poorly installed

• Blocking proper air sealing

Removing old insulation can also make it easier to inspect the attic, seal air leaks, address pest damage, and install a better-performing system.

Before choosing an insulation contractor, consider asking:

What insulation type do you recommend and why?

What R-value are you targeting?

Will old insulation need to be removed?

Will air sealing be included?

How will moisture or ventilation be handled?

What product will be used?

What safety precautions are required?

How long will installation take?

When can the space be used again?

Are there code or ignition barrier requirements?

What is included in the quote?

Do you handle residential, commercial, or both?

A good contractor should explain the recommendation clearly and not simply sell the most expensive product.