The higher the
Mold and Mildew Growth
Having too much insulation in your attic can allow for the accumulation of moisture. This leads to mold and mildew growth, which can be extremely bad for your health.
Looking across your attic, if the insulation is level with or below the attic floor joists, you probably need to add more insulation. If you cannot see any of the floor joists because the insulation is well above them, you probably have enough, and adding more insulation may not be cost-effective.
However, the DOE recommends that attics in Southern homes be insulated with 13 to 14 inches, or R-38, of insulation at minimum. Northern homes should have attics with 16 to 18 inches of insulation or R-49. If your home isn't insulated to the recommended thickness, you likely want to consider adding more insulation.
Warm loft insulation (Professional)
For the full recommended depth of 270mm, insulation must be installed between and beneath the rafters. You'll also need Building Regulations approval before work can begin.
The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.
The bottom line is the old insulation needs to be removed because it hinders the airflow into the attic, it can promote mold growth, and it is dirty.
Also, when laying down additional insulation, work from the perimeter toward the attic opening. Never lay insulation over recessed light fixtures or soffit vents. Keep all insulation at least 3 inches away from recessed "can" lights, unless they are rated IC (Insulated Ceiling).
A well-sealed and insulated attic can make a real difference in your energy bills and how comfortable your home is. Considering how high energy bills are these days, now is a great time to improve your home with a cost-effective project like sealing and insulating your attic.
When a home has inadequate insulation in the attic, a lot of air is lost through the roof. Energy bills skyrocket, and it's impossible to keep the temperature in the house regulated.
Should You Insulate the Attic Floor or Roof Deck? If you are looking for an insulation upgrade that you can see (on your energy bill) and feel (in a home that is more comfortable), we recommend insulating the attic floor, and using radiant barriers on the roof deck.
Pros of Blown-In Attic Insulation: Enhanced R-Value and Energy Efficiency: Blown-in insulation significantly improves your home's R-value, which is a measure of heat resistance. This means your home will stay warmer in the winter and cooler in the summer, helping you save up to 30% on heating and cooling costs.
Can I put plywood over insulation in the attic? Yes you can install plywood subflooring directly over the floor joists and insulation on your floor. You need to install rigid insulation boards on top of the attic flooring joists and then install plywood over the top.
Conclusion. Attic insulation can last 80 to 100 years, though it loses its energy efficiency benefits with time. Certified attic specialists' professional advice is to upgrade it every 15 years to ensure that it is still performing the job.
The Golden Rule of Attic Safety
These are the bones of your attic, offering the firm support needed to bear your weight. Ignoring this rule and stepping on the drywall or insulation is a fast track to an unplanned ceiling inspection from below, thanks to our unforgiving friend, gravity.
Insulation is graded by its R-value—the higher the R-value, the greater the insulating power. If you live in a mild climate, your attic should have a minimum grade of R-38, or about 13–14 inches of insulation. If you live in a colder climate, R-49 is the minimum recommendation, or about 16–18 inches of insulation.
IRS Form 5695: Claiming Energy Tax Credits
Use IRS Form 5695 to claim energy tax credits for various home improvements. This includes attic insulation. Annual limits are set at $1,200 for envelope improvements like insulation and windows and up to $2,000 for systems like heat pumps.
Fiberglass Batt and Roll Insulation
Fiberglass batt and roll insulation is a common and budget-friendly option. This insulation comes in pre-cut batts or long rolls, making it easy to fit between the framing members, like joists and trusses, in your attic.
However, insulation can start falling from fiberglass batts after 15 to 20 years, so if your insulation was installed in batts well over a decade ago, it might be time for an inspection or a home energy audit.
At first it may seem odd to add insulation for warmth and then purposely allow cold air to enter the attic through vents, but this combination is the key to a durable and energy-efficient home.
Blown fiberglass insulation scores an R-value of 3.2 to 3.8, making it slightly less likely than rolled fiberglass to prevent the flow of heat into and out of your house. That being said, though, blown fiberglass insulation isn't meant to cover huge areas like rolled fiberglass insulation.
Lowe's is here to help with our blown-in and batt insulation installation service. There are two types of insulation material to choose from, and which one you choose is up to you. Cellulose insulation, made from recycled paper and treated to be fire-resistant, is the most common material used.
You can use faced or unfaced batting when installing between the roof rafters of finished attic spaces. When using paper or plastic batting insulation, that moisture barrier should face outward toward the attic space. Even if the attic space is unheated, it's typically warmer than the outside air in winter.