What thickness of insulation is best?

Author: Keshawn Pacocha II  |  Last update: Tuesday, September 9, 2025

The recommended thickness for attics is typically 12-16 inches. Spray foam insulation: As discussed earlier, the recommended spray foam insulation thickness can vary depending on factors like climate and location. For attics, a thickness of 2-4 inches is usually sufficient.

Is R13 or R19 better insulation?

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. Now R-Value ranges widely across products and home applications.

What is the optimum thickness of insulation?

The results revealed that the optimum insulation thickness, energy saving, and life cost were in the ranges of 2–17 cm, 22–79%, and 1.3–4.5 years, respectively, depending on the different climate zones.

What is the best R-value for exterior insulation?

A good high R value exterior insulation wall would be 2x6 with 2'' roofing polyiso. That is an R30 assembly but it is hard to justify going above that based on energy savings, much more foam and your ROI is measured in centuries.

Does doubling the thickness of insulation double the R-value?

If you double the thickness of your insulation, you're essentially giving its R-value a twin sibling. Double trouble, double warmth!

How to Choose the Best Insulation for Your Home | DIY Home Renovation

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 it OK to double up insulation?

As a general guideline, it's advisable to install double layers of thermal insulation throughout your house. Nevertheless, this may not be feasible in all areas due to space limitations. Typically, it's not practical to add two layers of insulation within the walls of your home.

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.

What is the thinnest insulation with the highest R-value?

Thermablok® Aerogel is a revolutionary advancement in thermal technology offering the thinnest insulation available to prevent thermal and cold bridging. Classed as a Super Insulation, Aerogel has the highest insulation value of any known material with the lowest thermal conductivity value of any solid (0.015W/mK).

Is there a big difference between R13 and 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.

How do I choose insulation thickness?

Choosing the right thickness for your insulation depends on various factors such as climate, location within your home, and type of material used. It's crucial to do thorough research, consult with professionals, and ensure proper installation for maximum efficiency.

How thick should my insulation be?

R-Value is a measure of insulation's ability to resist heat flow. The higher the R-Value, the better the thermal performance of the insulation. The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.

What is the best thickness of insulation for preventing heat loss?

The recommended thickness for EWI typically ranges between 60mm and 100mm, depending on the type of insulation material used, the construction of your existing walls, and the age of your home.

What is R13 insulation good for?

Known for its sound reduction and easy installation, R-13 batts serve as a thermal barrier, keeping your home comfortable by resisting heat flow. Perfect for modern framing, they ensure minimal obstruction from electrical or plumbing work.

Why is insulation so expensive?

Many factors contribute to the high cost of insulating a new construction home. Between the quality of materials, labor costs, and regulatory compliance, insulation costs can add up quickly. Investing in premium insulation like spray foam is an expensive choice.

What is the most effective insulation?

Spray foam insulation is the most energy-efficient insulation to create an air barrier in the attic. Certain spray foams can expand up to 100 times its original size, so it fills all of the nooks and crannies in the attic.

Do I need faced or unfaced insulation?

For example, if you need extra soundproofing or don't want to spend time installing a separate vapor barrier, then face may be the best option for you. However, if cost savings are more important than convenience, then unfaced may be the better choice in this case.

Is foam board insulation better than fiberglass?

High R-value: Because foam board insulation has a greater R-value than standard fiberglass/batt insulation, it is more effective at insulating and decreasing heat loss.

Where not to insulate?

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.

Should I remove old insulation or just add more?

Removing old insulation is generally recommended if it's damaged, contaminated with mold, or infested with pests. However, if the insulation is in decent shape and just needs a boost, adding a new layer on top can be a cost-effective option.

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.

Is there a big difference between R13 and R19 insulation?

R19 Insulation offers superior thermal insulation compared to R13. With a typical thickness of 6.25 inches, R19 fiberglass is designed for use in 2x6 wall cavities, making them suitable for colder climates where higher thermal resistance is necessary.

Is 2 inches of insulation enough?

Two inches of closed cell spray foam might be enough insulation for some applications. However, for other applications, only two inches will not be able to deliver the results you need.

How much gap between insulation and boards?

If using rigid insulation boards to insulate your loft there must be a gap between the roof covering and the insulation to allow air to circulate. This prevents any build-up of warm air that could lead to condensation. For this reason, a minimum gap of 50 mm must be left between the two to prevent it occurring.

Previous article
What is the oldest detergent?
Next article
Who is responsible for 5S?