The ideal R-value for exterior walls typically ranges from R-13 to R-21 for standard cavity insulation, often supplemented by R-5 to R-10 of continuous exterior foam board. The exact best value depends heavily on your local climate zone and the thickness of your wall framing.
Depending on where you live and the part of your home you're insulating (walls, crawlspace, attic, etc.), you'll need a different R-Value. 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.
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.
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.
Yes, R-38 is technically better than R-30 because a higher R-value means greater resistance to heat flow. However, the "better" choice depends on your climate, space constraints, and local building codes, as R-38 requires more thickness and cost.
R-30 insulation typically requires a thickness of 8.5 to 10 inches, depending on the type of material you use. Because the thickness needed to achieve this thermal resistance varies by material, checking the exact product specs before buying is highly recommended.
Although R-38 insulation involves a higher initial investment because of the thicker material, it can yield up to 25% greater energy savings over time, especially in colder climates.
It is a common measure adopted by manufacturers, retailers, and even some contractors to ascertain the performance of insulation. Although R-value is important, it will not help you save on your power bills. The fact is, the energy efficiency of your home does not just rely on a number.
The top disadvantages of external wall insulation are:
R30 most commonly refers to a specific thermal resistance (R-value) rating used in building and construction. It measures an insulation material's ability to resist heat flow—the higher the number, the more effective the insulation.
What time of year is Insulation cheapest?
Closed cell spray foam is rigid once set. It is a better thermal insulator and was previously sold to stabilise failing roofs. But if it has been used inappropriately or installed poorly, it might put stress on timbers, restrict air circulation and put them at risk of decaying.
Mice are curious and always searching for safe, snug, and warm nesting sites. Attics filled with blown-in insulation provide an excellent option–from the mice's point of view. As long as there is a ready food source. Mice are omnivorous and will eat and chew on almost anything including wood and electrical wires.
R-values rate how well building insulation can prevent the flow of heat into and out of the home. Higher ratings mean greater insulation performance and thus more savings on your next heating and cooling bill.
External wall insulation (EWI) thickness generally ranges from 50mm to 200mm (2 to 8 inches) depending on your climate, space constraints, and the target energy efficiency. Standard residential installations typically use 90mm to 100mm to achieve ideal thermal performance (U-value) without making the walls overly bulky.
Thermal Resistance: R-21 polyiso boards offer higher thermal resistance compared to R-19, which makes them more effective at reducing heat transfer in colder climates.
To achieve an R-30 insulation value with rigid board insulation, you will need a thickness of 4.5 to 5 inches, depending on the specific type of foam board you use.
Factors that decrease property value the most fall into three main categories: location issues, structural damage, and poor neighborhood conditions. These factors can collectively slash a property’s value by 5% to 30% or more.
Yes, insulation is tax-deductible in the form of a federal tax credit, specifically the Energy Efficient Home Improvement Credit (Section 25C). You can claim 30% of the cost of insulation and air sealing materials, up to a maximum annual credit of $𝟏,𝟐𝟎𝟎.
When balancing upfront cost and overall thermal efficiency, the cheapest and most effective standard insulation is fiberglass batt insulation. However, if you are looking for long-term savings through superior air sealing, dense-pack cellulose often provides the best overall value.
Foam insulation is a common target because it's easy for them to chew through. The material offers little resistance, allowing mice to create tunnels or nests within the insulation. But mice aren't just interested in chewing for the sake of it—they're also drawn to the warmth and shelter insulation provides.
Yes, R-38 is technically better than R-30 because a higher R-value means greater resistance to heat flow. However, the "better" choice depends on your climate, space constraints, and local building codes, as R-38 requires more thickness and cost.
Although less common, R30 insulation can be used in exterior walls for homes in extremely cold or hot climates. The higher R-value ensures optimal protection against temperature fluctuations and energy loss.
It's recommended to leave an air gap insulation of at least 25mm or 1 inch for the walls and ceilings. This should be enough to allow for ventilation and prevent moisture buildup. The same rule may be applied when using foil insulation. On roofs, the air gap should be larger, typically around 50mm or 2 inches.