When to use R13?

Author: Gabriella Kling Jr.  |  Last update: Wednesday, February 11, 2026

R-13 insulation offers a balanced blend of cost-effectiveness and thermal resistance, making it ideal for standard 2x4 wall cavities, floors over unheated spaces, and crawl spaces.

What is R13 insulation good for?

R13 insulation is commonly used in ceilings in moderate climates. It helps to prevent heat loss in the winter and heat gain in the summer, which can improve energy efficiency and comfort. R15 insulation is used in ceilings in colder climates or buildings with high energy usage.

Is there a big difference between R13 and R19?

r19 just means its thicker insulation, made to fit into a 2x6 frame where the r13 is meant to fit in a 2x4 frame. the insulation is soft and will press in fine and won't offer as much of an air buffer in the insulation but will still accomplish the job just fine especially for a garage situation.

Where to put R13 insulation?

R13 batt insulation is typically used to attenuate sound in interior wall cavities. It is akin to a large blanket, designed specifically to fill a wall, floor, or ceiling cavity.

Is an R-value of 13 good?

Typical recommendations for exterior walls are R-13 to R-23, while R-30, R-38 and R-49 are common for ceilings and attic spaces.

Insulation R-VALUE - What is R-Value?

What is R13 used for?

R-13 insulation offers a balanced blend of cost-effectiveness and thermal resistance, making it ideal for standard 2x4 wall cavities, floors over unheated spaces, and crawl spaces.

Should I use R13 or R15?

R15 insulation offers slightly better thermal insulative properties than R13. Some of its formats are a fraction of an inch thicker than R13, making it more effective at helping with energy efficiency. However, the difference is minimal. R15 is slightly thicker than R13 for spray foam and blown-in cellulose.

Where should you not put insulation?

Never place insulation close to water heaters, oil burners or anything hot. The backing is especially flammable and will be a major fire hazard for your home.

Can you use R13 in 2x6 walls?

Fiberglass and rock wool batts—2x4 walls can hold R-13 or R-15 batts; 2x6 walls can have R-19 or R-21 products.

Is R13 or R30 better?

If you live in an area with moderate temperatures, R13 insulation can offer a cost-effective solution. However, for extreme climates or if superior energy efficiency is a priority, R30 insulation is the recommended choice.

Is it OK to use r19 insulation in attics?

You will want to bring up your attic up to R-38:

If your attic has 5-6″ of existing insulation, you'll want to install an R-19 to achieve a total of R-38.

Can you use R13 in basement?

R13 insulation provides excellent thermal resistance, making it ideal for basement walls. It helps keep the space warm in winter and cool in summer, ultimately lowering your energy bills. Additionally, it acts as a sound barrier, reducing noise between floors.

What is the best R-value for exterior walls?

According to the U.S. Department of Energy, R-values for exterior walls in colder climates should be at least R-13 to R-23. In milder climates, a lower R-value may be sufficient. For example, in a moderate climate, an R-value of R-13 to R-15 is typically recommended.

Is R19 worth it over R13?

R13 insulation is generally more affordable, which makes it an attractive option for budget-conscious projects. However, R19 insulation offers better long-term advantages because of its higher R-value. Why? Because the R-Value translates to a greater energy savings over time.

Is R13 enough for a garage?

Generally, insulation with an R-value between R-13 and R-21 is recommended. Adding insulation to exterior walls (including garage walls attached to living spaces) can help increase R-value and create a more powerful thermal boundary for your home. If you're insulating your garage ceiling, you'll need a higher R-value.

Can you over insulate a house?

It is possible to over-insulate your house so much that it can't breathe. The whole point of home insulation is to tightly seal your home's interior. But if it becomes too tightly sealed with too many layers of insulation, moisture can get trapped inside those layers. That's when mold starts to grow.

Is R13 enough for walls?

For walls, r13 insulation is a good choice in most instances, and because your basement is below the ground, there's some natural protection from the earth around it.

Can I double up R13 insulation?

Adding two R-13, 3.5” batts to a 2”x6” (5.5”) wood stud cavity will not provide an R-26. The total of 7” of insulation is reduced in thickness to 5.5” thereby losing the R-value associated with its full thickness.

When to use faced vs unfaced insulation?

Faced insulation is better at preventing moisture damage; however, it can't be layered like unfaced insulation. For this reason, unfaced insulation is better for keeping your house warm in the winter. It also offers better sound protection.

What ruins insulation?

Moisture damage

This can occur due to leaks in the roof or foundation, inadequate ventilation, or high humidity levels inside a building. Moisture can cause the insulation material to become compressed and lose its effectiveness, leading to increased energy consumption and potential mold growth.

What happens if insulation is installed backwards?

If installed incorrectly, moisture can become trapped between the facing and cause mold, rotting, and reduced R-value.

Should I insulate walls or ceilings first?

For new builds or if you are renovating, you may be asking yourself if you should insulate your ceiling or walls first. The best answer is both. Insulation is a once-only cost that makes your house more comfortable for it's entire lifespan, without another cent having to be spent.

Will R15 insulation fit in a 2x4 wall?

Excellent Thermal Performance Owens Corning™ R-15 EcoTouch® insulation is specifically engineered to solve the efficiency problems of exterior 2x4 walls. “High density” means more fibers per square inch. It delivers a higher R-value per square inch in less space than standard insulation products.

Can I use R13 instead of R14?

You will have to get 14 inch diameter wheels to mount the new tires on, as they will not fit on your existing 13 inch wheels (that's what the “R13” and “R14” numbers mean).

Is mineral wool or fiberglass insulation better?

Mineral wool batts are a great choice when it comes to thermal performance. They beat the fiberglass batts with a 22–37% higher R-value per inch.

Previous article
How to clean your eyes naturally?
Next article
Is travertine good for dogs?