R13 Insulation: Use, Thickness, Cost, And More

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Choosing the appropriate insulation should impact thermal resistance in homes positively. At this point, you’re wondering about R13 insulation. But what is it, and what are its ideal uses? Also, how thick is R13 insulation? We researched for your convenience, and here’s what we found.

R13 insulation is typically a 3-4/8-inch thick fiberglass batt with noise reduction properties. Generally installed in 2x4 wall framing, this heat-resistant material also does a fairly good job of managing moisture-related issues. Average prices for this insulating option usually fall within the $0.90 to $1.40 range.

Installers of R13 insulation should take note of different precautionary measures to finish these tasks with appropriate results. Keep reading as we talk about the steps to install R13 fiberglass batts in greater detail. We’ll also discuss other R13 insulation characteristics, such as its costs, thickness, and possible uses.

Huge blocks of fiberglass insulation installed in the walls, R13 Insulation: Use, Thickness, Cost, And More

What Do R-Values Mean?

The R-value is a coefficient measuring a material’s thermal resistance. Often used in insulation, it typically suggests high heat flow resistance as the measurement increases.

Moreover, R-values are cumulative. In other words, if you attach R10 insulation with another R2 material, the entire setup will have an R-value of 12.

What Does R13 Insulation Mean?

Fiberglass insulation on the wooden framing of a house undergoing construction

R13 insulation is generally a 3-5/8-inch thick fiberglass batt. By itself, it might not be sufficient to protect homes from extreme cold. Since insulation has additive R-values, adding extra layers of R13 insulation can produce excellent results.

Find out more about the thickness of R13 insulation by watching the video below:

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Where Is R13 Insulation Used?

Rock wool and fiberglass insulation between the wooden framing of the living room wall

Property owners and DIY enthusiasts can install R13 insulation between wall cavities. Its thickness makes it particularly useful in 2x4 framing.

Despite its lack of protection from freezing temperatures, R13 insulation often does a decent job in reducing outside noise from entering the premises. Some manufacturers produce R13 fiberglass insulation batts with a Noise Reduction Coefficient (NRC) of 90%. In turn, these options should absorb 90% of the outside racket and reflect the other 10% to its origin.

R13 insulation also does reasonably well in managing moisture. It typically minimizes condensation, which would otherwise promote mold and mildew growth. Find out more about an insulation’s moisture-resisting properties by reading our post on that topic.

How Do You Install R13 Insulation?

An insulation contractor taking a big roll of fiberglass insulation

Installing insulation, particularly R13 fiberglass batts, is usually a DIY-friendly operation. Still, proper preparation and prevention measures should exist to prevent costly mistakes.

For instance, make sure that you’re wearing protective equipment like a respirator, gloves, goggles, and long-sleeved clothing. Short-term exposure to airborne fiberglass can put you at risk of health issues, such as skin, nose, and throat irritation. You might experience coughing, itching, and/or wheezing if you leave yourself vulnerable to these particulates.

Also, take note that the best time to insulate your walls is during your home's construction process. Otherwise, the time and effort required to install the insulation become increasingly more significant than before. It's because you'd have to tear down the walls, install the fiberglass batts, then cover the exposed insulation.

The final step of the preparation process is to seal any cracks, gaps, or holes in your walls. These imperfections can create drafts and make the batts vulnerable to significant moisture damage.

After preparing for this task, you can proceed with the rest of the instructions:

What You’ll Need

  • Pre-cut R13 insulation batts
  • Stepladder
  • Utility knife
  • Staple gun
  • Vapor retarder (optional)

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Step-by-Step Guide

  1. Position the R13 fiberglass insulation onto the wall. Ensure that it faces the interior of the room. Climb a stepladder if necessary.
  2. Push the batt gently into the wall. Start from the top and work your way to the bottom. If the insulation is larger than the wall cavity, cut it to size with a utility knife.
  3. Staple the insulation to the joists. Certain R13 batt manufacturers have indicators to show you the correct areas to apply the staple.
  4. Repeat steps 1 to 3 for the rest of the wall cavities in the area.
  5. If your purchased insulation doesn’t have a built-in vapor retarder, install the barrier to each batt in the setup.
  6. Once done, cover the exposed insulation with another material like drywall.

Take note that not every state has building codes that require moisture barriers attached to insulation. But the International Residential Code (IRC) mandates these vapor shields in cold climate zones. Some examples include Iowa, Wyoming, and North and South Dakota.

Remember, the R13 insulation should fit snugly between each wall frame. You can cut the material if it meets obstructions like electrical and plumbing equipment. Additionally, don’t overstuff the batts into frames. If so, the excess material can cause the wall to bow.

Watch this video to learn additional details about this project:

Is R13 Insulation Good For Basement Walls?

R13 insulation is a good choice for basement walls. However, homeowners should still pay attention to the materials used to create that R-value.

In context, take note of the following R-values for relatively common basement finishing products:

  • Sealed plywood: R0.70
  • Vapor barrier or retarder: R0.45
  • Painted drywall: R2 to R3
  • Unpainted drywall: R0.50

Combining these materials may provide sufficient heat and cold resistance to basements. But these options may still lack structure, reducing their serviceability. With tough R13 insulation choices like high-quality fiberglass batts and closed-cell insulation, it's possible to hang heavy objects on basement walls like shelves and large-screen TVs.

Is There A Big Difference Between R13 And R19 Insulation?

Undergoing work in a house with visible fiberglass insulation between wooden framing

R13 often does a good job of reducing cold temperatures in many of the country's southern regions. Since many homes have 2x4 wall framing, particularly in their basements, R13 insulation is typically the primary choice for many property owners.

On the other hand, R19 insulation typically does a better job in resisting cold temperatures and retaining heat in houses. This insulating material also has better moisture-managing characteristics than its R13 counterpart.

What Is The Cost Of R13 Insulation Per Square Foot?

Homeowners should prepare to spend $0.90 to $1.40 to install R13 insulation per square foot. Expenses may increase if property owners choose professional services for the installation procedure. If so, expect to pay $0.60 to $0.90 per square foot for the expert assistance. The complexity of the job may also increase or reduce the overhead for this project.

What Is The Best Insulation For Exterior Walls?

Aside from R13 fiberglass batts, other insulating options for exterior walls exist to help increase a home’s thermal resistance. You can find these choices often divided into two main categories: open exterior walls and enclosed existing walls.

In this section, you’ll learn more about these options to help you make a sound purchasing decision:

Open Exterior Wall Insulation

Exposed exterior walls typically occur during a home’s construction phase. Insulation options for this setup are:

Foam Board

Styrofoam board insulation panels installed on the wall

Made by combining polystyrene (PS), polyurethane (PU), and polyisocyanurate (PIR), foam board insulation has a variety of densities, facings, and lengths. It’s a customizable choice for spaces that may have unique structures.

Unlike fiberglass batts, foam board installation is typically more difficult. Cutting the material needs to be as accurate as possible to seal gaps and prevent air leakage.

Spray Foam

An insulation specialist applying foam insulation on the wall

Spray foam insulation is an air- and heat-resisting substance that conforms well to relatively tight spaces. This option is ideal for homes with complicated electrical and plumbing systems. Lot owners may also take advantage of spray foam insulation’s energy-efficient traits to help reduce utility bills.

Learn more about spray foam insulation by reading our post on that material.

Enclosed Existing Wall Insulation

Insulation options also exist for homeowners that don’t want to undergo significant remodeling to increase their dwellings’ thermal resistance. Some of these choices are:

Blown-In Cellulose

Also known as loose-fill insulation, blown-in cellulose typically has excellent fire-resisting properties. These traits make it ideal for fairly hot states, such as Hawaii and Florida. Installers may even place this insulation around light fixtures without the worry of reducing fire safety.

Injection Foam

Like blown-in cellulose insulation, injection foam expands in walls and crevices to fit complicated structures. The difference is that injection foam often does a better job at creating airtight seals as compared to blown-in cellulose.

Final Words

Huge blocks of fiberglass insulation installed in the walls, R13 Insulation: Use, Thickness, Cost, And More

Installing R13 insulation is an ideal choice in homes that want to reduce outside noise. This option also has decent noise reduction properties to help reduce unwanted racket from entering indoor insulated spaces. If you find this type of insulation interesting, think about preparing about $450 to $700 to insulate a 500-square foot area.

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