While聽most聽homes have some insulation, have you ever聽considered聽whether or not your home has enough insulation? It聽creates聽an important layer of protection between you and the聽daily changes in聽conditions outdoors. Without聽enough聽insulation, you聽could聽be missing out on energy savings or a better sense of comfort.聽Adding聽new insulation can be a great investment,聽especially聽when you know where it will have the聽largest聽impact.
For聽a lot of聽homes, that includes their attic. Unfinished attics in particular can be much聽cooler聽than the rest of your home, even though heat rises. It can聽quickly聽escape聽through聽small cracks or other flaws.聽Adding聽more聽attic insulation聽to your attic can help your home聽retain聽more heating and cooling, and help you save more money as聽well. But how much insulation聽do you need聽in your attic?
Calculating How Much Insulation You Need
You’ll need to head聽up to聽the attic to聽determine聽how much insulation is already聽in place. Measuring is an easy process and can be聽handled聽with a measuring tape. Simply聽check聽the depth of the existing insulation against the聽closest聽joists. A good rule of thumb is that the insulation should measure several inches past the joists, but ultimately, you’ll need the measurement itself.
Your local climate聽impacts聽how much insulation is considered adequate.聽cooler聽climates聽need聽a few more inches of insulation compared to climates further south. This聽added聽insulation helps protect against the bitter cold and聽long聽winters more common in the northern part of the country.
While a聽thick聽layer of insulation is beneficial, the聽overall聽efficiency is also聽affected聽by the materials used. Some materials are more insulating than others, making them聽more efficient聽at聽minimizing聽heat loss. This resistance to heat flow is known as the R-value.
Make Sure Your Insulation has the Correct R-Value
Even if your insulation聽reaches聽past the floor joists, a聽low聽R-value means it’s not trapping as much heat as you might聽think. Cooler climates聽typically聽need聽an R-Value of 38 or聽higher, which roughly聽translates to聽12-14 inches of insulation. You聽may聽need more or less, depending on the material used for insulation.
What Type of Attic Insulation Is Best?
There are聽different聽materials used to聽manufacture聽home insulation. Each of these materials has a different R-value, and you’ll want to聽know聽them before deciding one insulator is better than another. We’ll聽review聽the 4 most common types and what their R-Values can range between.聽Don't forget聽that the climate聽alters聽what R-value is considered as enough insulation for your attic.
Fiberglass
Fiberglass insulation can be found in both loose fibers as well as standardized batts. Between these two types of fiberglass insulation,聽you can expect聽an R-Value of 2.2 to 3.8 per inch.
Cellulose
Shredded denim or paper fibers from old newspapers聽forms聽the bulk of cellulose-based insulation. It’s one of the oldest types of insulation and can offer an R-Value between 3.1 to 3.8 per inch.
Mineral Wool
Even rocks and minerals can be聽turned聽into soft insulation for your attic. Mineral wool, also聽called聽stone wool, is聽called聽from minerals like basalt. It can also be made from industrial slag or even glass. Mineral wool insulation offers a range of R-Values from 2.2 to 4.2 per inch.
Spray Foam
Unlike聽rolls or batts, spray foam insulation is sprayed directly onto the surface for insulation. This foam is made from聽several聽composite materials and conforms to the shape around it. Spray foam insulation can offer some of the highest R-Values, averaging 3.5 to 8 per inch.
Can You Have Too Much Insulation?
While it seems聽correct聽to assume that more insulation聽equals聽higher energy efficiency, there’s such a thing as too much insulation. Excessive insulation can聽spur聽mold growth and trap other airborne particles聽within聽the fibers. Unless you’re experienced with evaluating and installing home insulation, it’s best to leave the job to聽a pro.
Professional installation聽ensures an even distribution throughout your attic, from the center of the floor to the spots closest to the roof. This consistent聽layer聽will give your home the best layer of protection. If you’re considering installing more attic insulation in聽the U.S., look for technicians that can evaluate your existing insulation. They’ll be able to justify why your home needs however many additional inches of insulation.
