Can I Insulate Between Floors of a House?

Using wall and roof insulation throughout the home is the best way to make a more comfortable indoor environment, save on your energy bills and improve energy efficiency. Insulation between floors is probably the most overlooked place in a house to install insulation. Insulating between floors can give you all the thermal benefits of insulation, and can also provide a solid control of noise transfer between the floors. When building or renovating a multi-story house or building, it’s highly recommended to insulate between the floors. If the intermediate area between the floors (the area between the ceiling of the ground floor and the floor of the second story) is exposed, installing insulation is a fairly straightforward process. It can be much harder to install insulation if the plastering has already been done.

How to Insulate Between Floors

Mid-floor insulation is typically installed from the lower floor when the ceiling cavity is exposed. You will need to take the next steps in order to properly install insulation:

  • Seal up any holes with an acoustic sealant. For example, holes for electric wires or plumbing.
  • Insert the batts between the ceiling joists, ensuring a snug fit and making sure there are no gaps between the different batts. It’s important to buy the correct width batts to suit the distance between your ceiling joists for the best fit. Using 10M Prodex Total Plus or 48 Prodex Total 5M will save you some hassle as these models of insulation are easier to cut into the exact shapes you need and provide you with exceptional thermal and acoustic insulation.
  • Consider installing resilient channels and then plaster to help combat impact noise from above. The resilient channel will ensure the plaster does not touch the ceiling joists, minimizing the amount of vibrations that pass through.

If your garage is located under a living space (such as a living room or bedroom), it’s crucial that you insulate between floors and maybe even get acoustic insulation to prevent unwanted noise transfer (car noises, for example). Improved thermal insulation will make the living space more comfortable, preventing warm air from escaping in winter and keeping hot air out during summer.

Be sure to know how much insulation you’ll need before starting. Contact a professional to get expert advice or you can use our advanced insulation calculator for a quick estimation of the amount of insulation you'll need.

If you are insulating an attic for a livable attic space, insulating between attic floor joists is a good way to help control noise and heat transfer.

Should You insulate between floors?

Installing insulation is a useful method to control and isolate temperature in a certain area, or help with noise reduction. House insulation helps improve the air temperature by minimizing heat exchange from adjacent surfaces, such as walls, attic, and roof. Insulation between floors also deflects updrafts of air from the room below while also preventing heat from escaping to the floor above. After insulating, you needn’t worry about sudden temperature changes and you should expect comfortable air temperatures.

The pros of insulating between floors can be:

  • Warmer Rooms - Insulation means your rooms will be warmer. Since one layer of insulation can improve a room, adding more layers will result in a more comfortable temperature. Along with that, the transfer of heat will decrease. For instance, if there is a kitchen on the floor below, adding insulation between the kitchen and the room helps prevent the heat from cooking from penetrating through the ceiling. At the same time, the air temperature in the room above this kitchen will not escape easily. However, you should check on how much warmth the insulation can give you. The room should have proper ventilation and a source of air so that too much warmth will not cause discomfort. If your main concern is to improve ventilation, you can simply add a circulator fan to your room.
  • Less Floor Moisture - Because the transfer of heat is prevented, moisture can’t pass through the barrier as well. With insulation, the floors will be able to block liquid particles caused by the cold temperature. After installing, you’ll feel that the floor is drier. The room can also stay warm during winter. However, you need a source of heat to support the insulation in blocking moisture. You can turn on the furnace or have an air dehumidifier. Insulation alone can not completely block moisture. You can add a carpet to your floor to help absorb excess moisture. Moisture can be a big problem in pole barns. If you have multiple floors, choosing the right pole barn insulation for between floors can be a lifesaver.
  • Space-saving - You'll save a lot of space, considering that the insulation is hidden between the floors. The room can appear as spacious as a room without insulation. You will save approximately two inches of space because that's how thick the insulation is. Basement and wall insulations are typically 4-6 inches thick because basements and walls are exposed to nature's heat and moisture, like sunlight and rain. Floor insulation is different. It can be thin since the only heat it blocks is the temperature from the room below or above.

On the other hand, there are a few cons to insulation between floors:

  • Risky When Wet - By wet, we mean water coming from leakages. You have to ensure that the pipes connecting across the rooms are sealed to prevent water from making the insulation wet. If the insulation is already installed, you need to remove it to avoid electrical shock. You also need to repair the broken water pipes. Another thing is that mold may grow if the insulation is exposed to water. It will create an updraft of stinky air or even make the floor too heavy. If you're not aware of the water leakage, then the floor might collapse.
  • Difficult to Start - You need the help of a professional to further assess your home, especially if the foundation of your house is finished already. Floor insulation is usually done during the construction of the house. This is to check to find out if the wires and other factors like air vents have been properly placed. You might need to remove all the things inside your house before you can start insulating the floor. Remember that the floor is the ceiling of the room below. You need to decide if there's adequate space for insulation.
  • The Effect Can Be Permanent - Once you decide to have insulation between floors, the effect can be permanent. It means that you cannot remove the insulation easily, or that you'll spend a lot of time replacing the insulation. That's why it's important to have a thorough evaluation of the house.

Knowing the right type of insulation that you will need is very important. After all, the needs for metal building insulation and ordinary house insulation aren’t the same. The most common types of insulation for between floors are:

  • Fiberglass - it’s very flexible, making it easy to install on almost any surface, like wood or cement. Considering that fiberglass contains fire-retardant materials like sand and recycled glass, there's a low risk of catching fire.
  • Rockwool - it’s very good for mold prevention and noise cancellation. When used as insulation, rockwool does not serve as a heat conductor. This means that heat cannot pass from one surface to another.
  • Foam - costly, but it does a very good job at blocking water and heat. FAST ACTION Prodex Total 5M foam insulation is probably the fastest type of insulation to install.

Is It Necessary to Insulate Between Floors?

The two main reasons for installing insulation between floors are to reduce noise and thermal transfer between the two floors.

If your main concern is acoustic isolation, getting acoustic insulation between floors can help create a quieter home. Acoustic batts are thicker than traditional ones, making them better at reducing unwanted sounds, along with all of the benefits of thermal insulation.

The laws of physics make it so heat naturally travels from places of high heat energy to places of low heat energy. This means that your house wants to cool down during winter and warm up during summer. The best way to prevent unwanted heat loss and gain is to use insulation throughout the home, including between floors. Mid-floor insulation can reduce heat loss and gain between the different levels of your home, creating climate zones. Using insulation will make your air conditioning systems and appliances work more efficiently at keeping a stable temperature, and in turn use less electricity, thus reducing your energy bill.

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