The best overall choice for interior walls is mineral wool (stone wool), specifically products like Rockwool Safe'n'Sound. It is highly dense, providing exceptional sound dampening between rooms, superior fire resistance, and an easier, less-itchy DIY installation than standard fiberglass.
Fiberglass Insulation: Affordable, widely available, and easy to install. With an R-value of ~R-3.0 to R-4.3 per inch, it's a good option for walls, attics, and floors. Rigid Foam Boards (Polyiso, XPS): Excellent for energy efficiency, with R-values of ~R-5.0 to R-6.5 per inch.
R19 is technically better for energy efficiency because it provides greater thermal resistance, but it is not inherently better for every situation. The best choice depends on the depth of your wall framing.
Insulated interior walls will prevent large temperature swings that can crack drywall. These insulated rooms will also hold their temperature longer. For rooms that aren't used frequently, like guest rooms or storage rooms, interior wall insulation can reduce heat transfer and help you save on your utility bill.
To quickly block cold air and drafts, seal gaps around baseboards and outlets with Great Stuff Insulating Foam. For larger wall surfaces, you can hang thick insulated thermal curtains, apply reflective radiant barriers like Reflectix Rolls, or install rigid foam boards.
Closed cell spray foam is rigid once set. It is a better thermal insulator and was previously sold to stabilise failing roofs. But if it has been used inappropriately or installed poorly, it might put stress on timbers, restrict air circulation and put them at risk of decaying.
The most effective way to insulate walls without removing drywall is the "drill and fill" method. Installers drill small holes in the drywall or siding, blow in dense-pack cellulose or inject expanding foam into the cavities, and patch the holes, leaving your interior mostly intact.
Yes, you can add insulation to existing interior walls. For interior walls, the goal is typically soundproofing rather than thermal control. The two most common approaches are using blown-in insulation (which requires minimal wall repair) or removing the drywall to install batts or acoustic panels.
Insulation materials themselves generally maintain a consistent baseline price year-round, but late fall and winter (November through February) are typically the cheapest times to hire contractors for installation. During these off-peak months, demand drops and contractors are more likely to offer 10% to 25% discounts to secure work.
Yes, rodents absolutely love foam board insulation. While it offers no nutritional value, the soft texture is incredibly easy for mice and rats to chew through. They shred it to build warm, insulated nests, and use the boards to create extensive, hidden tunnel systems within your walls.
The cheapest and most effective insulation overall is blown-in cellulose for attics and fiberglass batts for open walls. Both materials provide excellent thermal resistance (R-value) for their price and are widely accessible for both DIYers and professionals.
Yes, mice absolutely love blown-in fiberglass insulation. It provides a soft, warm, and highly structured environment for nesting, tunneling, and breeding.
It's recommended to leave an air gap insulation of at least 25mm or 1 inch for the walls and ceilings. This should be enough to allow for ventilation and prevent moisture buildup. The same rule may be applied when using foil insulation. On roofs, the air gap should be larger, typically around 50mm or 2 inches.
R-values rate how well building insulation can prevent the flow of heat into and out of the home. Higher ratings mean greater insulation performance and thus more savings on your next heating and cooling bill.
Depending on the type and thickness of the insulation used, typically between 50mm and 100mm, this can impact room dimensions—particularly in smaller spaces.
Yes, mice can chew through and tunnel in rockwool (mineral wool) insulation. While rockwool is denser, fireproof, and doesn't provide nutritional value, its loose fibers and coarse texture actually make it an attractive material for mice to gather and shape into nests.
Buyers often walk away from homes with spray foam insulation because it can cause major mortgage and insurance denials. The foam tightly seals roof spaces, trapping moisture, and covers up structural timbers. This makes it impossible for surveyors to inspect for hidden rot or damage, which can lead to catastrophic repair costs.
Professional insulation installation typically costs between $1.50 and $4.00 per square foot, with an average total project cost of $1,500 to $4,000. Your exact price will depend heavily on the location in your home, the material used, and local labor rates.
Home insulation doesn't have an “expiration date,” and the material doesn't “go bad” after a certain number of years have passed. Ultimately, the condition of the insulation and its performance are more important factors than age when deciding whether to upgrade or replace insulation.
Interior walls are frequently left uninsulated during construction because the energy efficiency benefits aren't as great as insulating exterior walls, floors and ceilings.
Yes, you can insulate existing walls without removing your drywall using a method commonly known as "drill and fill." This method involves drilling small access holes into your wall cavities, blowing or injecting insulation into the space, and patching the holes.
While it may appear harmless to the naked eye, it actually contains thousands upon thousands of small shards of glass and sand that can make their way onto your skin, eyes or even inside your lungs. If you've ever touched fiberglass insulation with your bare hands, you're probably well aware of its effect on the skin.
Yes. Injection foam is installed through small holes drilled into the exterior siding or interior wall cavities -- no drywall removal or major remodeling needed.
While the average cost to insulate a wall ranges between $1 and $4 per square foot, several factors will determine your final project price. Insulation costs for existing walls will cost more than those for installing insulation during the construction of a new home or during a remodel or addition installation.
To insulate a cold wall from the inside, you can either inject loose-fill insulation into existing stud cavities, or install insulated plasterboards (rigid foam boards with drywall attached) directly to the masonry. This traps heat in your room and creates a comfortable barrier against freezing exterior temperatures.