An R-value measures resistance to heat flow. For 12 inches of insulation, the total R-value heavily depends on the specific material used:
To achieve R-40, we install 12” of cellulose insulation. To achieve R-50, we install 15” of cellulose insulation.
For 2" x 4" walls; excellent thermal control.
Twelve inches of fiberglass insulation has a total R-value between R-26 and R-52, depending on whether it is a dense batt or loose-fill blown-in material. The total R-value is calculated by multiplying the material's thickness by its specific R-value per inch.
To achieve an R-30 value, blown-in insulation typically needs to be 9 to 10.5 inches thick. The exact depth depends on the material used, as blown-in fiberglass typically settles at 10 to 10.5 inches, while blown-in cellulose requires about 9 inches.
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.
While having a deep layer of blown-in insulation is excellent for your energy bills, you can put too much in if it blocks your attic's ventilation. Piling too much insulation over your eaves and soffit vents restricts the airflow needed to control moisture, which can eventually lead to wood rot, mold, and roof damage.
Fiberglass Insulation: The most budget-friendly choice (~$0.40-$0.70 per square foot) with solid R-value performance.
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.
R60 blown-in insulation provides maximum thermal protection, requiring a depth of 17 to 22+ inches depending on the material. It is designed for top-tier energy efficiency (IECC Zones 6-8) and ensures a heavily insulated, comfortable home. Proper installation, including marking joists, is crucial for maintaining consistent density and preventing settling issues.
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.
For a standard 2x4 framed wall (which is actually 3.5 inches deep), the best insulation performance comes from maximizing the cavity fill while preventing heat loss through the wood studs.
Usage. Walls: Ideal for insulating interior and exterior walls to improve energy efficiency and sound control. Floors and Ceilings: Suitable for use in floors and ceilings to provide thermal insulation and reduce sound transmission.
Most regions fall into recommendations ranging from R30 to R60, with R49 and R60 representing the higher end of the spectrum. These premium R-values typically make sense in extreme climates or for homeowners prioritizing maximum energy efficiency.
Yes. Compressing fluffy insulation (like fiberglass or mineral wool) reduces its total R-value. This happens because you squeeze out the trapped air pockets that give the material its insulating power.
Insulating a 2,000 sq. ft. attic costs between $2,000 and $9,000, with most homeowners paying around $3,600 to $5,800 for professional installation. The wide price range depends on the type of insulation, labor rates, and whether old insulation requires removal.
The Amish control mice through non-chemical, self-sustaining methods, relying on active trapping, natural scent repellents, and structural exclusion. Rather than using commercial poisons, they focus on physical barriers and natural predators to keep rodent populations in check.
Because spray foam can trap moisture, hide the condition of the roof, make it difficult for surveyors to inspect, which means risks like timber decay, dry rot, and not forgetting increased fire risk. If you've got it or you're buying a property that does, this is something you need to know upfront.
The ultimate "number one" mice killer depends on your specific needs—whether you prefer fast-acting poison or a safe, pet-friendly option.
What time of year is Insulation cheapest?
Potential problems with spray foam insulation
reduce air circulation and ventilation within a roof space. lead to dampness and condensation on the underside of a roof because it forms an air barrier and stops moisture from escaping. place timber-framed roofs at risk of decay.
The absolute thinnest insulation with the highest Rcap R𝑅-value is Aerogel, which provides an incredible Rcap R𝑅-10 to Rcap R𝑅-12 per inch. For more budget-friendly applications, Polyisocyanurate (Polyiso) foam board offers the best everyday value, delivering about Rcap R𝑅-6 to Rcap R𝑅-6.5 per inch.
Blown-in attic insulation should generally be 10 to 14 inches deep to achieve an R-38 value, or up to 16 to 18 inches deep to reach an R-49 value. The exact depth depends on your local climate, whether you are using cellulose or fiberglass, and if you are topping off existing insulation.
The 7 and 7 rule for attic conversions refers to the common requirement that finished attics be at least 7 feet wide and 70 square feet, with 7-foot ceilings over at least half. Keep in mind that this is a general guideline. Local building codes may have stricter requirements that supersede this rule.
Unfaced insulation is great for new construction, remodels, walls, floors, ceilings, basements, attics and crawlspaces. It's best used for interior wall applications that do not face the outside and also in rooms that don't need moisture control, like living rooms, dining rooms and studies.