Table of Contents
How much insulation do I need in my ceiling?
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.
Can you have too much insulation in your ceiling?
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.
How do I calculate how much insulation I need?
Measure the length and width of all exterior windows. Subtract the area of windows, doors, or walls you aren’t planning to insulate. [(Interior perimeter × height) − (window and door area + any walls/areas not insulating)] ÷ 144 = total square feet.
Is R38 insulation good?
In many colder areas of the US, R 18 is the recommended insulation for walls (its a 2×6 wall stuffed with standard fiberglass insulation), R 38 (14 inches of fiberglass) is recommended for ceilings/attics.
Is R30 insulation good?
R30 insulation can minimize conductive heat loss out of your home by 97 percent, and this will make your home 97% hotter than without insulation, saving you a lot of money on your energy bill.
How thick is R30 insulation?
8¼ ” thick, R-30C EcoTouch® Thermal Batt insulation prevents moisture damage and helps assure long roof life by providing 1″ of ventilation air space between the insulation and roof deck.
What insulation has the highest R-value per inch?
Vacuum insulated panels have the highest R-value, approximately R-45 (in U.S. units) per inch; aerogel has the next highest R-value (about R-10 to R-30 per inch), followed by polyurethane (PUR) and phenolic foam insulations with R-7 per inch.
Can you put batt insulation over blown in?
A: There’s no problem with installing fiberglass batts over your existing blown-in insulation. The reason for this precaution is that the facing on the insulation batts is a vapor barrier, which is intended to prevent moisture vapor from penetrating into the insulation.
How many bags of insulation do I need for 1000 square feet?
If you’re aiming for R-30 (a common recommended value for attics per the Home Depot chart), the GreenFiber chart gives 40.8 bags per 1,000 square feet of gross coverage. Divide the measured square footage you obtained by 1,000 square feet to obtain the multiplication factor: 1,500 square feet/1,000 square feet = 1.5.
How much insulation do I need for a 24×24 garage?
What’s the Cheapest Way to Insulate a Detached Garage? Insulation Type Cost/square foot of insulation (R-13) Total Cost to Insulate 24×24 Detached Garage (R-13) Batts – Mineral Wool $0.75 $1,012.50 Batts – Cotton $0.89 $1,201.50 Loose Fill – Cellulose $0.15 $202.50 Loose Fill – Fiberglass $0.24 $324.00.
How much will a bag of insulation cover?
ft.
What is the difference between R38 and R49?
A ceiling with an R-value of 38 lets through only 1/38 of the amount of energy per square foot that passes through that window, or about 2.6% of the energy; a ceiling with an R-value of 49 lets through only 1/49 of the amount of energy per square foot that passes through that window, or about 2.0 % of the energy.
What is R-38 used for?
Easy to handle and pre-fabricated batts with a thickness or depth of 11.25″ will be needed to attain an R-value of R38. It is used in floors of crawlspaces and attics, supplying water-resistant insulation with no forming of mildew, fungi, or mold.
What is R 44 insulation?
Fiberglass Chart R-Value Thickness Max Net coverage per bag R49 16.25” 44.2 R44 14.75” 49.8 R38 12.75” 59.5 R30 10.25” 77.0.
How many inches do you need for R30?
For future reference, here is the cavity depth you need for some common insulation r-values: 3.5 inches — R13. 6 inches — R19. 9 inches — R30.
How much space do I need for R30 insulation?
Take a two by two and nail it to the bottom of the rafters. Give yourself another inch and a half, put the R30 in there. All you need is about a half inch to three quarters of an inch air gap in there. You don’t need anything big, and make sure it’s vented.
What is the R-value of 4 inches of insulation?
For areas with 3-4 inches of existing insulation, you will need an R-value of 38-49. For insulating flooring, you will need an R-value of 25-30.
Is R30 insulation better than R19?
Insulation in your walls and ceilings slows down this heat transfer. The bigger the R value, the better the insulation is at slowing down the heat transfer. So R19 is better insulation than R13, and R30 is better than R19. The larger the R value, the better the insulation value.
What is the R-value of 3 Rigid insulation?
R-Value Chart for EnerfoilTM Rigid Foam Faced Insulation Thickness (Inches) R-value (in I-P/Imperial) RSI (R-value in Metric) 2.0 12.4 2.16 2.5 15.5 2.7 3.0 18.6 3.24 3.5 21.7 3.78.
How many square feet are in a bundle of R30 insulation?
x 24 in. x 48 in. Batts (88 sq ft/bag).
