How Much Insulation Do I Need in My Attic?

Krista M.
Sep 25
4 min read

If you’re like most homeowners in Memphis, Collierville, Germantown, or the broader Mid-South, you’ve probably wondered: How much insulation do I really need in my attic?

It’s a smart question, because attic insulation plays one of the biggest roles in your home’s comfort, energy efficiency, and even roof health. The truth is, many homes in our region are under-insulated—and that means money is literally escaping through the roof every month.

In this guide, we’ll break down:

What attic insulation does
What “R-value” means and why it matters
The recommended insulation levels for Memphis and the Mid-South
How many inches of insulation that translates to
The benefits of adding more insulation
How to know if your attic is under-insulated
How Restoration Insulation can help

Why Attic Insulation Matters

Your attic is more than just a storage space. It’s a barrier between the living areas of your home and the extreme outdoor temperatures we experience in the Mid-South.

In summer, attic temperatures can climb to 140–160°F. Without enough insulation, that heat radiates downward, forcing your AC to work harder to keep the house cool. In winter, heat rises and escapes through the attic, driving up heating bills and leaving you chilly.

Proper attic insulation helps:

Maintain consistent indoor comfort year-round
Reduce heating and cooling costs
Protect your roof by reducing heat and moisture buildup
Improve indoor air quality by limiting drafts and condensation

Understanding R-Value

Insulation is measured by its R-value, which tells you how well it resists heat flow. The higher the R-value, the better the insulation performs.

Low R-value = Poor insulation (heat easily escapes or enters).
High R-value = Strong insulation (better temperature control and efficiency).

Different insulation products achieve different R-values per inch. For example:

Fiberglass blown-in insulation: about R-2.7 per inch
Cellulose blown-in insulation: about R-3.2 to R-3.8 per inch
Spray foam insulation: about R-6 per inch

That means the number of inches you need depends on the type of insulation you choose.

Recommended R-Value in Memphis & the Mid-South

According to the U.S. Department of Energy, homes in Tennessee and surrounding states fall into Climate Zone 3. For attics in this zone, the recommended insulation level is R-38 to R-60.

Here’s what that looks like in practical terms:

R-38 = about 12–14 inches of fiberglass or 10–12 inches of cellulose
R-49 = about 16–18 inches of fiberglass or 14–15 inches of cellulose
R-60 = about 18–20 inches of fiberglass or 16–18 inches of cellulose

At Restoration Insulation, we typically install fiberglass blown-in insulation, which is durable, long-lasting, and cost-effective. That means most Mid-South homes should have 12–20 inches of insulation in their attics.

How to Tell If Your Attic is Under-Insulated

Not sure if your attic has enough insulation? Here are some signs:

Visible joists: If you can see the wood beams in your attic floor, you almost certainly need more insulation.
Uneven coverage: Gaps, low spots, or compressed insulation reduce effectiveness.
High energy bills: If your heating and cooling costs seem higher than your neighbors’, under-insulation may be the culprit.
Hot or cold rooms: Bedrooms upstairs that are sweltering in summer or freezing in winter are a red flag.
Drafts and uneven temps: If some areas of your home feel different from others, your attic isn’t insulating evenly.

A quick DIY test: if your insulation is below the top of your attic joists, you need more.

Benefits of Adding More Insulation

Upgrading your attic insulation delivers big returns:

Lower energy bills – Many homeowners save 15–25% on heating and cooling costs after adding insulation.
Increased comfort – No more hot upstairs bedrooms in July or drafty living rooms in January.
Extended roof life – Proper insulation and ventilation keep roof temperatures balanced, reducing stress on shingles.
Better indoor air quality – Reduces moisture, mold risk, and pollutants entering through the attic.
Boosted home value – Buyers in Memphis appreciate energy-efficient homes with modern insulation.

How Restoration Insulation Installs Blown-In Insulation

When you work with us, the process is simple and fast:

Inspection & Measurement – We evaluate your attic, measure current insulation levels, and check ventilation.
Preparation – Our crew ensures the attic is ready, sealing any obvious air leaks.
Blown-In Installation – Using specialized equipment, we blow fiberglass insulation evenly across the attic floor. This creates a continuous, blanket-like coverage with no gaps.
Final R-Value Check – We confirm your attic now meets the recommended R-value (R-38 to R-60).

Most homes can be completed in just a few hours, with immediate results.

Cost of Adding Insulation

Costs depend on attic size, desired R-value, and product choice, but in the Mid-South, most blown-in insulation projects average $1.00–$1.50 per square foot installed.

That means a 2,000 sq. ft. attic could cost $2,000–$3,000—an investment that often pays for itself in just a few years through energy savings.

Why Memphis Homes Need It Most

Our Mid-South climate makes attic insulation even more important. With long, humid summers and big swings in temperature, homes without enough attic insulation face:

AC units running constantly in July and August
Heat buildup that can shorten roof lifespan
Moisture problems that lead to mold and mildew

By upgrading to R-38–R-60, Memphis homeowners enjoy cooler summers, warmer winters, and lower bills year-round.

Let Restoration Insulation Help

At Restoration Insulation, we specialize in blown-in fiberglass insulation for homeowners in Memphis and the Mid-South.

Our team has years of roofing and insulation experience, so we know how to design the perfect system of insulation and ventilation for long-term protection and comfort.