What is the difference between R13 and R19 for garage walls?

Author: Mattie West  |  Last update: Monday, September 1, 2025

R-value is used to judge thermal insulation performance and the higher the number, the better the product's insulating ability. So R19 has better insulating ability than R13.

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 R19 insulation good for a garage?

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.

Is R13 insulation good for garages?

R13 is about 92% reduction in heat transfer. R19 is about 2-3% better than R13. It's an exponential decay in heat transfer, so you'll be fine with it for a garage. Use the thicker stuff for the attic to reduce transfer from the attic to the garage.

What is the best R-value for garage walls?

Exterior Garage Walls

Typically these will be constructed from standard 2-by-4 studs which will define the amount of insulation that you can have installed. You should be targeting an R-Value of R-13 or R-15 in these areas to properly maximize your insulation in this application.

Insulation R-VALUE - What is R-Value?

What is the best insulation for a 2x4 garage wall?

Use R-13 or R-15 kraft-faced fiberglass or mineral wool insulation rolls for 2x4 stud walls. Wall assemblies, especially those in older homes, are built with two-by-four (2x4) studs. The wall thickness will be 3-1/2 inches, not 4 inches. The width of modern 2x4s is 3-1/2 inches.

Do you need a vapor barrier when insulating garage walls?

The majority seem to agree that insulated, unheated garages, should be allowed to breathe. If the garage is heated, you will need a vapor barrier, otherwise you will get frost and mold.

What thickness insulation for garage walls?

To achieve optimal U-value, garage wall insulation is generally recommended to be 50mm to 100mm thick.

Where to use R13 insulation?

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.

How much does it cost to insulate a 24x24 garage?

The cost to insulate a 24' x 24' garage is $3,000 - $8,000. Garage size influences the cost of insulation. The 24'x24' garage will house 2 cars and some extra space for other purposes. The average cost to insulate a 24x24' garage with spray foam is $6,000.

What is the difference between R13 and R19 garage?

R-value is used to judge thermal insulation performance and the higher the number, the better the product's insulating ability. So R19 has better insulating ability than R13.

Can you put R19 in a 2x4 wall?

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.

Does it make sense to insulate an unheated garage?

Attached garage insulation can reduce the cost to heat or cool your home. Creates more comfortable living spaces. An insulated garage makes it easier to control the comfort in adjacent spaces.

Is R13 OK 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 you have too high of an R-value insulation?

The optimal R-value for most homes is 30, but you can go as high as 38 if you live in a tropical climate. Anything higher than 38 indicates an over-insulated space.

Is R-19 insulation good for garage ceilings?

By our rough estimate, for a garage heated consistently throughout the winter, insulating four walls, garage doors, floor, and ceiling to R-19 would result in about $1050/year in energy savings!

Does R13 insulation need to be stapled?

All you'll need is a few staples and your wall is insulated. Its thermal insulation performance (R-13) compliments an interior wall assembly nicely (for exterior walls we do suggest blown-in or R20).

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.

Do you have to tape insulation seams?

PFT installation expert Jared explains that you are not required to tape the seams of PFT insulating sheathing and fanfold underlayments. However, we do recommend that you check with your local building codes for your specific application.

What insulation is best for garage walls?

We recommend using fiberglass insulation, since this type is easier to handle and can be used throughout the entire garage, including the walls, floors and ceiling. If you plan to use a different type of insulation, we suggest hiring a professional, since other materials can require more experience.

What R rating for garage walls?

What R-value insulation should I use in my 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.

Does garage wall insulation need a vapor barrier?

Homes in areas with high humidity and occasional temperature drops will also experience garage condensation. Combining a vapor barrier with Comfortbatt® insulation will further improve moisture control in the space as it's water and moisture resistant. It does not absorb moisture to maintain its insulating value.

Should I use faced or unfaced insulation in my garage?

Faced insulation is also a good idea if you are putting in first time insulation. Perhaps you've liked the warmth and energy protection of an installed insulated garage door and want even more insulation. If you're already adding insulation over existing insulation, faced insulation isn't necessary or suggested.

Should I put plastic over insulation before drywall?

Should I Put Vapor Barrier Plastic Over Insulation Before Drywall? Yes, covering your insulation with a vapor barrier plastic before installing drywall is crucial. It prevents moisture buildup that can lead to mold, rot, and even structural damage.

Do you need drywall over insulation in garage?

Some garages have traditional ceilings that run perpendicular to the floor and have a crawl space above them. To make things easier, you'll need to install drywall before adding insulation.

Previous article
What is the best insulation for coolers?
Next article
Which brand of toilet is the best?