What R-value should you have in your attic?

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.

What is the code for insulation in an attic?

Sacramento and most of California are in Zone 3, which requires attic insulation with an R-value between 30 and 60.

What thickness of loft insulation is recommended?

The recommended depth for loft insulation is 270 millimetres for glass wool, 250 millimetres for rock wool or 220 millimetres for cellulose. There are a number of grants and schemes available to home owners which can substantially reduce the cost of installing these products.

Which is better attic insulation blown or rolled?

Rolled fiberglass insulation scores an R-value of 3.7. So overall, rolled fiberglass insulation is slightly more effective at blocking in and out heat than its blown counterpart.

Can I insulate the underside of my roof?

Open-cell spray polyurethane foam or closed-cell spray polyurethane foam (ccSPF) insulation can be sprayed along the underside of the roof sheathing to provide a conditioned and insulated attic space that can be durable and efficient in all climate zones (see Figure 1).

What happens with no insulation in attic?

Without proper insulation, warm air from a home’s heating system will flow directly to the house’s colder areas, like attics, garages, mudrooms, and basements. With an insulated attic floor, the temperatures in the house’s upper levels are heated evenly, and much less warmth is lost through the attic.

How do I know if I need more attic insulation?

Looking across your attic, if the insulation is level with or below the attic floor joists, you probably need to add more insulation. Assumes R-3/inch. 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.

Can you put new attic insulation over old?

According to ENERGY STAR®, you can put new insulation over old insulation, “unless it is wet. Any new batt or roll insulation installed over existing insulation in the attic needs to be without a vapor retarder (face). The vapor retarder on top of or between layers of insulation can trap moisture.

How do you add insulation to an attic?

To add insulation to the attic floor, you will require enough blanket material to do the job, a heavy-duty shop vacuum, plastic sheeting for covering the blanket material that will insulate the attic opening, a heavy-duty staple gun, and utility scissors with long blades. You will also need a strong board to kneel on that will span the joists.

How to add insulation in an attic?

How do I Add Insulation to Existing Attic Insulation? Calculate Insulation Needs. Measure how much insulation you already have. Install Fiberglass Batts Over Existing Batt Insulation. Put on goggles and gloves to protect yourself while handling fiberglass insulation. Add Loose Fill Insulation to Existing Loose Fill. Rent a loose-fill insulation blower from a home improvement or hardware store.

How much insulation should I add to my attic?

In Zone 1, the average minimum requirement for attic insulation is 9 inches of R30 fill. The average recommended level is 14 inches of R49. In Zone 2, the average minimum requirement for attic insulation is 9 inches of R30 fill.

What is the best insulation for an attic ceiling?

Batt insulation comes in rolls, or batts, and is the most common type of insulation. It is generally made of flexible fiber or fiberglass, but other materials are available. Fiberglass batts are usually preferable for attic insulation.