Insulation of a concrete floor

Although concrete floors are strong and long-lasting, they can also be uncomfortable to walk on, especially in colder climates. An efficient method of improving the comfort and energy efficiency of your house or building is to insulate the concrete floor. Whether you’re building something from scratch or remodeling an existing area, adding insulation can have a big impact.

There are various ways to insulate a concrete floor, and each has advantages and things to keep in mind. Options range from insulated concrete forms (ICFs) to rigid foam boards, meeting a variety of needs and price ranges. The climate, how the floor is used, and the building’s overall design are some of the variables that influence the choice of insulation material and method.

In addition to increasing thermal comfort, properly installed insulation for concrete floors lowers energy costs. Insulated floors can maintain a more constant interior temperature by minimizing heat loss and lowering the need for excessive heating or cooling. This is especially crucial in ground-level floors and basements because uninsulated concrete allows cold air to easily seep through.

The ability to soundproof concrete floors is another benefit of insulation. Your home can become quieter and more serene by using insulation to reduce noise. This is especially useful for homes with high foot traffic areas or multi-story buildings.

All things considered, making an insulation investment for your concrete floor is a sensible first step toward creating a cozier, quieter, and more energy-efficient space. Finding a solution that meets your unique needs is now simpler than ever thanks to the variety of materials and techniques available. Examine your options and speak with an expert to choose the best course of action for your project.

Choosing insulation

An analysis of the room-specific thermal insulation technology is the first step. The material must have low heat conductivity and be resistant to moisture and temperature fluctuations. The insulation determines how the finished floor is laid up.

A rigid finishing surface needs to be installed for fibrous, sprayed, and partially for bulk materials. Monolithic sheets work best when choosing how to insulate a concrete floor beneath a laminate.

Common kinds of materials used for thermal insulation:

• Mineral wool. It is made by heat treatment of basalt rocks. As a result, hollow fibers are obtained, which are bound with a special composition. Advantages – not flammable, retains heat well. Disadvantages – low density, requires installation of a finished floor.
• Foam. Despite good heat -insulating qualities, insulation of concrete floor with foam in apartments and second floors of private houses is not recommended. It has low mechanical strength, an additional screed or a system of wooden logs with a floor covering is needed on top of the sheets. This increases the load on the interfloor overlap.
• Extruded polystyrene foam. Unlike foam plastic, it has a higher density (up to 75 kg/m³), which allows you to install a decorative coating on top of it – linoleum, parquet. Advantages – ease of installation, minimum heat loss at the joints. Disadvantages – flammable material.
• Expanded clay. After firing a mixture of clay and shale rock, small balls with a porous structure are obtained. There are a number of restrictions on use, granules absorb moisture well, a large volume of material is needed to create a good heat-insulating layer. You can insulate a concrete floor with expanded clay on the first floor of a private house, in a garage or a bathhouse.

It is not practical to use sprayed coatings (polyurethane foam, ecowool) for comparatively small volumes of thermal insulation. The need for specialized equipment to form a layer raises costs.

For any building to be more comfortable, long-lasting, and energy-efficient, its concrete floors must be insulated. Homeowners can drastically cut down on heat loss by adding insulation, which will result in cheaper energy costs and a cozier living space. Additionally, insulation aids in preventing moisture accumulation, which can lead to mold growth and structural damage. The performance and comfort of your home can be greatly improved by knowing the advantages and techniques of insulating a concrete floor, whether you’re building a new house or remodeling an old one.

Calculation part

The heat insulator’s R (m2 * C / W) heat transfer resistance must be determined before selecting a technology. This is the total R of all the layers. R shouldn’t be any lower than 3.3 for the best possible heat conservation. The heat transfer resistance of a concrete coating with a thickness of 230 mm is 0.29. This value has to be raised by 3.01.

Next, choose a heat insulator and determine its thickness using its thermal conductivity. Multiply the thermal conductivity by the residual R value to achieve this.

An illustration of how to use expanded polystyrene to insulate a concrete floor in a home or apartment is as follows: 0.084 m = 3.01 * 0.028

Expanded clay will have the largest thickness, measuring 3.01 * 0.16 = 0.48 m. As a result, it is more frequently employed to provide a cushion of heat insulation beneath reinforced concrete foundations. The thickness for mineral wool in this case will be 3.01 * 0.034 = 0.102 m.

It is advised to round the results up to the nearest ten to fifteen percent reserve. This is required to provide extra security against heat loss in the event that the outside temperature drops unusually low.

Concrete floor insulation technologies

It is imperative to consider the room’s operational characteristics. For instance, thorough waterproofing needs to be completed before insulating a bathroom’s concrete floor. If not, moisture will seep into the concrete’s structure and cause some of it to break down.

Using heat insulators with little to no moisture absorption is an exception. Polymeric materials, such as foam plastic or extruded polystyrene foam, are among them.

The initial phase of preparation is universal for all kinds of technologies. Grease stains, residues from various materials and compositions, and large cracks in concrete are sealed. In the event that bulk heat insulators are not utilized, leveling the surface is advised. The room’s height differential shouldn’t be more than 1.5 cm for every meter. Utilizing leveling mixtures is the solution.

A specific kind of waterproofing is chosen for every room in a private home because the concrete floor must be insulated throughout. Vapor-waterproofing is preferable to using waterproofing film for living rooms (bedrooms, hallways, and living rooms).

It will assist in getting rid of extra moisture from concrete while lowering the chance that water will damage the insulation. Waterproofing is the only thing required for the wet rooms, the kitchen and bathroom. You can use special mastic or polymer materials.

Continuous layer

Expanded polystyrene can be utilized for this technique. Extruded is the preferred option due to its superior rigidity. No need for extra battens or logs to serve as supporting structures.

The creation of cold "bridges" at the joints is an issue with sheet materials. Heat loss will rise as a result. Installing sheets with specific grooves is the solution. They have an overlap when mounted. But a preliminary cut is necessary in order to apply penoplex to properly insulate a concrete floor.

1. Preparing the base.
2. Laying waterproofing. The layers should be overlapping, fastened to each other with construction tape.
3. Damper tapes are installed near the walls. They minimize the effect of thermal expansion of polystyrene foam.
4. Checking the level.
5. Installation of the finished floor.

Dowels are not required to secure the polystyrene foam to the floor during proper installation. The sheets and the ends (locks) should fit snugly. Insulating a concrete apartment floor beneath parquet or laminate flooring is a convenient application for this technique. It won’t give the necessary surface rigidity, so it’s not appropriate for linoleum.

Frame method

This approach is used with soft insulation, like wool from basalt. The key is to add a lag system, which is an extra structure, to the concrete surface. On top of them is mounted a finishing base composed of OSB, chipboard, or similar materials. In the space between the joists is a heat insulator.

The joists must be dried before insulating a concrete floor beneath linoleum, and their dimensions must be verified.

Phases involved in putting in a frame structure.

1. Marking the base for the joists. The distance between them is 0.5-0.7 m.
2. Installation of a wooden structure. The joists are located along the length of the room, wooden lintels are installed between them for rigidity. Waterproofing under the base. Contact between concrete and wood must not be allowed.
3. Laying the insulation. Its height should be 1.5-2 cm less than the joist level. This is necessary to form a ventilation gap.
4. Installation of a vapor-waterproofing film.
5. Distance strips are attached over the joists.
6. Installation of the finished floor.

Crucial! Because basalt wool absorbs moisture, using it in a kitchen or bathroom without excellent waterproofing is not advised. The heat transfer resistance index will drop as a result.

Under the screed

Convenient if you intend to lift a sizable load on the surface. Here’s how to insulate a garage or utility room’s concrete floor. Above the layer of insulation, a screed is applied. This technique applies to setting up electric floor heating or warm water. The heat insulator’s thermal effect will be lessened by the screed.

This method works with any material: polystyrene foam, expanded clay, and basalt wool. However, it is advised to install a metal frame over the insulating layer when using wool. It will lessen compression by distributing the weight of the concrete equally.

How to create insulation against heat under screed.

1. Laying waterproofing.
2. Installing a damper tape along the perimeter of the walls. Its height should be 2-3 cm more than the thickness of the screed. After the surface has dried, the remainder can be cut off.
3. Insulation installation, sealing joints.
4. Laying vapor-waterproofing.
5. Installing a metal mesh (frame).
6. Pouring concrete.

The final layer should be homogeneous and no thicker than three to four centimeters. If not, the heat insulator will experience an increase in load, which will cause compression to cause the thickness to decrease. This is not limited to materials made of polymers, such as polystyrene foam.

Common mistakes

Many details need to be considered in addition to selecting the appropriate insulation and determining its thickness. First, get the material ready for installation. It is stored indoors at room temperature after being unpacked at least one day prior to the start of work. In this manner, it will accept standard linear dimensions that, once installed, won’t change all that much.

The subsequent elements are also considered:

• After installing the heat insulator, the upper decorative and protective surface (finished floor) is mounted as quickly as possible.
• Pre-treatment of logs with an antiseptic. This will protect them from the appearance of fungus, mold.
• The use of impermeable membranes to protect against water can provoke an increase in humidity in one of the layers. It is better to use a vapor barrier.
• Sealing of joints, there should be no cold "bridges".

Expanded polystyrene can be applied continuously to an apartment or residential building’s floor to provide insulation. Basalt wool installation is more challenging on logs. Thermal insulation is installed beneath the screed in a garage. All materials, including expanded clay, can be used in this situation. It’s critical to meet the prerequisites, which include having a strong surface mechanical strength and an effective thermal insulation indicator. Permissible loads on interfloor ceilings are taken into consideration in apartments.

Taking the proper measures to insulate a concrete floor can significantly improve the comfort and energy efficiency of your house. Appropriate insulation lowers heating and cooling expenses and helps maintain a steady temperature, whether you’re working on a new construction or renovating an old floor.

Selecting the appropriate insulation material is essential. Every option, including foam board, spray foam, and fiberglass, has advantages and disadvantages, so weigh your needs and financial constraints. The material itself is not as important as proper installation. To prevent any problems later on, make sure that all of the seams and gaps are tightly sealed.

Spending time and energy insulating your concrete floor will pay off in the long run. Not only will your living area be more comfortable, but your energy costs will probably go down as well. You can establish a comfortable and effective home environment that will last for many years with the appropriate strategy.

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