Does Fiberglass Attic Insulation Really Lose R-Value?
Jan 9, 2019 · The loose-fill fiberglass, however, showed a significant reduction in R-value as the attic got colder and the temperature difference got larger. In fact, the loose-fill fiberglass lost 35% to 50% of its resistance to heat flow at temperature differences of 70°F to 76°F. The loss of R-value started at a temperature difference of about 32 F°.
fiberglass nodules in today’s loose-fill insulation significantly improve cold-weather performance compared to the products available to the Oak Ridge researchers in 1991. Fay says that R-value degradation in today’s loose-fill fiberglass insulation doesn’t occur until attic temperatures drop to –20°F. If that’s true,
Blown-In or Loose-Fill Insulation - GreenBuildingAdvisor
Feb 1, 2010 · Fill the Whole Framing Cavity — Even Irregularly Shaped Ones. ##ABOUT BLOWN-IN OR LOOSE-FILL INSULATION. Typical wall and ceiling cavities aren’t uniform in size; some are 22 1/2 in. wide, while others are narrow. They can include electrical boxes, wiring, plumbing vents, and blocking. Because of these variations, it’s hard to get batt ...
Insulating Stud Cavities in Existing Homes
Dec 4, 2012 · Loose-fill fiberglass has become quite popular for DIY insulation projects, as the Big Box stores (rhymes with “Dome Hepot”) are more likely to stock it than cellulose. The installation process remains the same, and if homeowners fill a stud wall cavity, they’ll achieve similar R-value, uneven insulation density, and lack of air leak ...
Adding Blown-in Fiberglass Insulation - GreenBuildingAdvisor
Fiberglass insulation. Watch Fine Homebuilding contributing editor Mike Guertin increase the R-value in an attic from R-15 to R-40 with blown-in fiberglass insulation. Mike uses Owens Corning’s AttiCat system to add approximately 9 in. of insulation between the attic ceiling joists. This short video includes tips on everything from safety ...
Fiberglass versus Cellulose - GreenBuildingAdvisor
Mar 5, 2012 · Cellulose and fiberglass are fibrous insulation which can easily trap moisture. If paired with a vapor barrier in a high moisture environment like your basement … it can be problematic. Wind washing: Lastly, when blown onto the floor of an attic with vented soffits, both loose-fill cellulose and fiberglass are susceptible to wind.
High-Density Fiberglass Batts vs Dense-Pack Dry-Blown Cellulose
Feb 11, 2012 · Here's a photo of Spider fiberglass blown in a ceiling as densepack with Insulmesh netting. There's about 3 inches of closed cell blown against the roof sheathing and rafters, some strapping, and the Spider blown against that. The walls received the same treatment but with 2 inches closed cell in the walls.
Mineral Wool Insulation - GreenBuildingAdvisor
Aug 22, 2022 · Mineral wool in cavities. When compared to fiberglass batts, mineral wool offers superior insulation. It has about a 22-37% higher R-value per inch. It contains 70% recycled material, making it a greener product than fiberglass at 20-30%. Mineral wool retains its shape better than fiberglass or cellulose.
How to Install Cellulose Insulation - GreenBuildingAdvisor
Mar 11, 2011 · Insulation expert Bill Hulstrunk provides detailed instructions for blowing loose-fill cellulose on attic floors and dense-packing walls. A 3-inch hose works fine for loose-fill cellulose. The fastest way to move cellulose to an attic floor is through a big 3-inch hose. In some parts of the U.S. — notably northern New England — cellulose ...
Advantages of fiberglass for loose-fill attic insulation?
Sep 29, 2011 · The R-value of loose-fill fiberglass is very low -- about R-2.5 or R-2.6 per inch -- so you need a huge pile to do any good. You asked a hypothetical question about R-75 of loose-fill fiberglass. Such a layer would be 29 inches deep, and most attics don't have 29 inches available, especially at the perimeter under the eaves.