The higher the
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.
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.
The recommended amount of attic insulation can vary based on your location and local climate. However, a general guideline is to aim for an insulation level of R-30 to R-60. Here's a breakdown: R-30: Suitable for warmer climates, providing adequate insulation for moderate temperature variations.
Insulation levels are specified by R-Value. 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.
You will want to bring up your attic up to R-38:
If your attic has 5-6″ of existing insulation, you'll want to install an R-19 to achieve a total of R-38.
Do I Have To Remove Old Insulation? Unless your insulation is wet, moldy or infested with pests, you don't need to remove it before adding insulation on top of it. ENERGY STAR® recommends that you inspect your insulation for signs of mold, mildew, moisture and pest infiltration before making this determination.
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.
With an average savings of 15%, a family of four could save $924.58 each year after installing new insulation in their attic. An extra $900 a year to spend on groceries, clothes, or school supplies would make an enormous difference for working families.
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.
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).
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.
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.
If your home, or upper floor, is too hot in the summer and too cold in the winter it is likely that you have insufficient attic insulation. If a visual inspection of your attic identifies that the insulation is level with or below the attic joists – you need more insulation.
Drywall has a relatively low R-value — about 0.45 at ½” thickness. This is similar to building materials such as siding, concrete, dirt, face brick, particleboard, wood and single-pane glass. However, it is significantly less than materials that are commonly used for insulation.
Cellulose is an eco-friendly and cost-effective insulation for attics. Fiberglass and mineral wool are also popular choices because they are good at keeping heat in or out and resist moisture and pests. Special equipment blows the loose-fill material into the attic spaces, ensuring it covers everything evenly.
Blown-in attic insulation is one of the most effective ways to enhance your home's thermal performance and reduce energy bills.
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.
While loft insulation is an effective way to improve energy efficiency and reduce heating costs, over-insulating can lead to several potential issues. Firstly, over-insulation can lead to poor ventilation in the attic, which can cause moisture buildup and increase the risk of mould growth.
On average, attic insulation costs $1 to $3 per square foot, so for a 1,800-square-foot attic, you'd pay $1,800 to $5,400, including materials and labor.
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.
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.
The material should be faced if you install batting between your attic floor joists. Since the attic floor is the ceiling of the living space below, the facing is installed against the top of the ceiling drywall or plaster.