4 Types of Home Insulation Explained


We’re at the mid-way point of December, and winter is knocking at the door. In the coming weeks, temperatures will be going down and heating bills will be going up. Now is the time to beef up your home’s insulation, whether you intend to DIY or hire a pro.


Here are four types of insulation broken down by description, usage, and cost. Use this as a guide to get your home’s insulation ready for the season.


  1. Expanding Foam


What it is: This foam is made of either open-cell or closed-cell polyurethane and is applied as a soft foam that fills spaces and stiffens in place. It is only applied by professionals, making it a costlier option. The material can expand up to 100 times its volume, so it is superior in plugging air leaks.


Best use: Use when cost isn’t a barrier and you want to invest in long-term comfort.


Cost: About $1.50 per square foot, including labor, if the wall is open – but, $2.25 per square foot for existing walls.


  1. Insulation Batt


What it is: Batts are like thick blankets that are purchased in long rolls or precut to fit in between studs. Most commonly, they are made of fiberglass, but they also exist in cotton and wool forms.


Best use: Use when you want to do it yourself, but the walls must be broken down to the studs.


Cost: Batts will run you anywhere from 40 cents per square foot uninstalled to about $1. However, wool is most expensive, at about $2.75 per square foot.


  1. Loose Fill


What it is: This material consists of dry bits of insulation that is blown into wall cavities through holes 1 – 2.5 inches wide. It can be blown in from interior walls, requiring you to patch holes, or from the exterior, requiring you to lift up siding and drill through the sheathing.

Best use: Use loose fill to shore up attic-floor insulation or inside existing walls to save money.


Cost: Fiberglass and cellulose fill cost about $1.20 per square foot when blown in from the inside and $2 per square foot from the outside.


  1. Sprayed-on Fiber


What it is: This option works only for stud walls that have yet to be dry walled. Professional installers add water and adhesive to insulation materials and spray it between studs.


Best use: Use sprayed-on fiber when you want a pro to handle the job and you are on a budget.


Cost: This option costs about 50 percent more than loose fill.