How much blow in insulation do i need

Finn McCuhil is a freelance writer based in Northern Michigan. He worked as a reporter and columnist in South Florida before becoming fascinated with computers. After studying programming at University of South Florida, he spent more than 20 years heading up IT departments at three tier-one automotive suppliers.

He now builds wooden boats in the north woods. By Finn McCuhil. Related Articles. How to Install Copper Pipe Insulation. In this case, the calculation is: The number of bags per 1, square feet required to achieve a given R-value varies widely with application as well. Attics, walls and enclosed areas have different ratings and compaction factors. To install blown-in insulation in existing walls, holes are drilled at the top of each stud space usually on the exterior , and material is blown in via a long, flexible hose.

The hole is then sealed with a plug that matches the siding. While the plugs are closely matched to the color of the siding, if the siding is brick or stucco, the plugs are often noticeable. Another disadvantage to blowing insulation into wall spaces is that an obstruction in the wall—such as a drainpipe, an outlet box, or any other type of unseen barrier for example, a cross-board between studs the builder might have added for stability —can keep the insulation from filling the entire stud space, leaving a void with no insulation.

After a few years, blown-in insulation tends to settle downward by a few inches, which slightly reduces its overall thermal resistance known as R-value , because it leaves a small section at the top of the stud space uninsulated. The three most common types of blown-in insulation are loose-fill fiberglass, cellulose, and rock wool—each with its own pros and cons. Minimum suggested insulation values vary by geographic zones, and you can find the recommended values for your region on this Energy Star map.

The higher the thermal resistance R-value , the greater the insulating effect. Not all types of blown-in insulation offer the same thermal value, but in most cases, even adding a little insulation is better than not adding any at all. See below to learn about taking this on as a DIY project.

How deep is r30 blown insulation? How long does blown in insulation last? How many bags of insulation do I need calculator? Note: the cost is based on rounding up the number of bags needed. What is the best attic insulation? Keep in mind that even the best insulation will not protect your home from the cold if it's not installed properly.

Typical attic insulation types include cellulose, fiberglass, mineral wood, spray foam, and rigid foam. Is spray insulation worth the cost? The initial cost of spray foam insulation is well worth the investment, when factoring in the overall savings that will be headed your way over the long term.

How much is a bundle of insulation? The cost of a single roll of reflective insulation varies according to its R-value. Can you put new insulation over old? The vapor retarder on top of or between layers of insulation can trap moisture. Any existing batt or roll insulation in the attic should have the facing against the attic drywall floor or no facing at all.

What is the best blown in insulation? The best insulation options for an attic are open cell spray foam, fiberglass, and cellulose.