Take a step in the right direction and stomp out your floor drafts
Everyone warns you about the cold that filters through windows and doors. No one remembers to mention the drafts that sneak through the floors and turn them icy. Instead of shooting across the room on the tips of your toes, you can take the steps to insulate your floors and get your home to the right R-value. Before you make socks a permanent part of your at-home wardrobe, these floor insulation tips can help increase your home’s comfort and decrease your energy bill.
Correctly installing insulation can be difficult. Health and safety risks are involved; therefore, we highly recommend contacting a pro to ensure the job is completed safely and correctly.
Insulation conversations usually cover walls—interior and exterior—and attic/roof insulation. It’s easy to forget floors, but they also play a supporting role in keeping your home cool in the summer and warm in the winter.
Heat flows from warmer areas to colder areas. When unheated spaces are colder than heated rooms, warm air escapes through walls, ceilings, and floors until the temperature of the house is balanced. Insulated floors help prevent rooms, like your basement or attic, from stealing heat from the areas where you really need it, like your bedroom and other common areas.
The most obvious benefit of an insulated floor is the comfort it allows you in keeping your house temperature controlled, but that’s not all. Insulated floors make your house more energy efficient. While that might seem like a relatively minor change, the return is big once you take note of the difference in your monthly energy bill.
Beyond increasing your home’s energy efficiency, insulating a floor can soundproof a room and reduce noise, improve air quality, and even fireproof your home with the right fire-resistant insulation.
The cost of insulation depends on several factors—insulation material, installation location, square footage, and labor. On average, homeowners can expect to pay $0.30 to $6.75 per square foot of insulation. Polystyrene is the most affordable option and averages around $0.25 to $0.50 per square foot. Wood fiber, the more sustainable but more expensive alternative, lies at the higher end of insulation costs and will increase the overall budget of your insulation project.
A suspended floor is one that doesn’t sit directly on the ground. It’s usually supported by sleeper walls and wooden joists, so it stays elevated. This elevation keeps the area below your floor ventilated so you don’t run into moisture issues that lead to mold and rotting wood. But there’s a catch. The airflow that keeps your subfloor ventilated can lead to drafts if the area isn’t properly insulated—or insulated at all. Ultimately, your house may wind up expending more energy, and you’ll expend more money to keep your home heated or cooled.
If the floor of your home is accessible from below, you may be able to insulate your subfloor from there. It’s cheaper but relies on space and whether your insulation—and, more importantly, you—can fit into the nooks and crannies for proper placement. Although above-floor insulation requires a lot more work and money, it’s often more readily accessible than the alternative.
Underlayment is a material—used in flooring and roofing—made from foam, cork, rubber, sponge, and more. It’s a common solution for insulating wood, vinyl, laminate, and tile floors.
To insulate a suspended floor using underlayment, you will need to:
Remove flooring
Clean subfloor
Repair subfloor
Lay out underlayment one row at a time
Secure underlayment with tape or staples
(Re)Install flooring
As opposed to suspended floors that sit a few feet off the ground, solid floors are built directly on them. Because of this, your floors become susceptible to the conditions of the ground below. Is the ground cold? So is your floor. Any wet conditions of the soil could cause dampness on your floors and could make the conditions beneath your feet wetter and even colder.
Insulation can’t be laid beneath a solid floor. Unless you’re going through a major renovation, any insulation will have to be added on top of your flooring. Unfortunately, these changes can cause issues with the fixtures in your home, for example, if your doors have enough clearance at the bottom to open.
For the quickest fix, add a layer of underlayment to your floor before covering it with a carpet. If you want something more substantial, you might:
Rubber isn’t often considered the most aesthetically pleasing, but that’s because we liken it to a car tire. With the variety of colors you can incorporate, it can add design value to your home.
Rubber flooring has many advantages that might make you think twice before turning it down. It’s moisture-resistant, and because it’s also skid-proof, you won’t have to worry about any children or seniors slipping and sliding across the surface, even when it is wet. The surfaces are great shock absorbers, natural noise reducers, and easy to clean. And while there may be a rubbery smell when first installed, it disappears after a few days.
To install rubber surfacing, you need to:
Prep your floor by removing any coatings, paints, or other products
Clean your floor and let it dry
Place protective paper underlayment on the floor (to protect from staining)
Lay plastic edging around the perimeter
Mix rubber and adhesive
Place the mixture in small piles on the floor
Spread and level the rubber mixture
Smooth surface
Repeat until the entire floor is covered
Let the surface dry for at least 24 hours
On the scale of beginner to experienced homeowner, insulation projects aren’t always an easy task. The job becomes progressively more challenging when you factor in removing floorboards.
A useful how-to can help, but there are always niche tricks of the trade that often go unshared. If you decide to insulate your floors, you can perfect the job by following this list:
Insulate floors above unheated and unconditioned spaces—crawl spaces, basements, and garages.
Always check to see if you can insulate your floor from below first before deciding to pull up your floor.
Use quilt-type or other flexible types of insulation—like wool—to insulate a floor with wooden joists from below.
If pulling up your floor, number your floorboards to place them back in the right spot.
Make sure your subfloor surface is flat, dry, and damage-free before installing any insulation.
Use staples and/or nails to keep insulation taut and prevent it from moving against the subfloor.
Fill cracks in your floor by using a flexible filler to block any remaining drafts.
Insulating a floor is easily done during a new build, but considering the fact that most homeowners purchase an “old build,” it’s not surprising that floor insulation is a renovation to consider sometime in the future. Insulation projects can be DIY-friendly, but they aren’t necessarily beginner-friendly.
Tackling the project yourself can save you money on labor but cost you a great deal of time and effort. Prep work requires research to figure out the right R-value for the project and gather the right tools and equipment. This is all before the task of pulling up your floor. And if you’ve never done that before, let a local flooring company handle the job.
You should note that most insulation jobs—like blown-in insulation—require special equipment. In this case, you’ll need the work and expertise of a professional. While the varying cost factors of insulating a floor make it difficult to come up with an accurate estimate, hiring an insulation professional usually costs between $575 and $750.
R-value is a measurement that dictates how much resistance an insulation material has against heat flow—or how well it can stop heat from coming and going. A higher R-value, which is attributed to thicker and more dense materials, means the better the insulation performs.
There is not one universal recommended value. It depends on climate zones. For example, Alaska, which has a naturally cold and arctic climate, has higher R-value recommendations than the hot and humid Hawaii.
Underfloor insulation alone will not cause moisture and mold, but improper installation can. Although the purpose is to seal any drafts, your subfloor still needs ventilation. If you seal the area too tightly and prevent all airflow, this can cause moisture to get trapped. This moisture eventually leads to mold and—if your floors are wood—rotting.
The thickness of floor insulation will depend on the R-value you plan to achieve. R-value varies on the type of material as well as its thickness and density. Insulation materials with low R-values can be layered to match the value of denser materials. As long as your floor insulation is packed tightly, seals the area from drafts, and doesn’t prevent ventilation, it can be as thick (or thin) as you need.
