Do-it-yourself installation of a warm floor in a garage

The question of how to make a warm floor in the garage with your own hands is common today. It is asked by suburban developers who are trying to build a warm garage for their cars. But before proceeding to the analysis of the topic, you need to decide what is meant by the term «warm floor». This is an insulated floor with a heat-insulating material laid in its design or is it a heating system. In order not to rack your brains, consider both options.

Insulated floor

Let’s start from this position, because the laying of the insulation is carried out at the stage of formation of the floor base. First of all, you need to choose a thermal insulation material. There is little variety here, because the floor of the garage is subjected to quite serious loads. Therefore, for thermal insulation, either bulk materials or high-density slabs will be required.

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The first ones include:

• expanded clay;
• perlite;
• vermiculite and more.

To the second — plates of expanded polystyrene. With slab insulation, not everything is so simple. Here you will need a material whose density should be above 150 kg / m³.

Warming technology

Before you insulate the floor in the garage, you need to choose a heat-insulating material. Optimal — bulk. It’s easier to work with him. The only thing to consider is the thickness of the layer to be filled. If it is expanded clay, then at least 20 cm. If perlite or vermiculite, then 10-15 cm after tamping.

The sequence of operations performed:

1. The area between the foundation elements is cleared of debris and vegetation, leveled.
2. Sand is backfilled with a thickness of 30 cm. This size is not chosen in vain, because sand can pass moisture through itself only 30 cm upward. In fact, the sand layer performs the functions of waterproofing.
3. A layer of crushed stone with a thickness of 10-12 cm is poured.
4. A waterproofing base is laid from roofing material, folded in half, or from a polymer film. The main thing is to make the layout so that the film covers the side planes of the foundation.
5. Thermal insulation material is poured, which is leveled along the horizon.
6. Another layer of waterproofing.
7. Installation of a reinforcing frame made of steel reinforcement, which is made in the form of a grid with cells of 20×20 cm. Please note that the grid is laid on delivery. The goal is for the reinforcement cage to be inside the concrete solution. Stone, brick, metal profiles or special iron or plastic structures that are sold in stores are used as coasters.
8. A concrete solution is poured, which forms the floor in the garage. Its thickness is not less than 10 cm.

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Some subtleties of technology. Is a reinforcing frame necessary? Not always. If the garage is being built for one car, then the thickness of the concrete screed can be increased to 20 cm. And this will guarantee that the floor will not crack or sag under the weight of the car.

When a concrete floor is poured over the ground, it is recommended to leave a small gap between the screed and the foundation surfaces. It is called damping or compensatory. Therefore, before concreting the floor, it is necessary to lay a damper tape along the side planes of the foundation structure.

Insulation with polystyrene boards

Is it worth it to use this material at all? If you choose the required density, taking into account the thickness — not less than 10 cm — then this is a good option. Expanded polystyrene plates today are produced with a tongue-and-groove lock, so that the heat-insulating surface will be without gaps and cracks.

The sequence of ongoing processes:

• A pillow of sand and gravel falls asleep.
• A thin screed 5 cm thick is poured. PP boards are laid only on a solid and dense surface.
• Waterproofing is being installed.
• Insulation plates are mounted, which are easily cut to the required size using a conventional saw or knife.
• The second layer of waterproofing.
• Pouring concrete mortar either along the reinforcing frame, or without it.

Heating system «warm floor»

What you need to consider before making a warm floor in your own garage? It is necessary to choose the heating system itself: electric or water.

Let’s start with the first and outline its pros and cons. The benefits include:

• uniform heating of the entire garage area;
• ease of installation and connection, which requires one outlet;
• small equipment, where simple devices go;
• floor heating temperature up to + 27C, which is a safe condition for the operation of the garage.

As for the disadvantages:

• electricity is the most expensive type of fuel;
• the complexity of the repair, if the cable burned out in some area or the insulation was broken.

Water heated floor

In fact, this is pipe wiring on the floor, which is connected to a heating boiler or stove. Features of the operation of a water heating system underfloor heating is that inside it the water should run with a temperature of no more than + 65C. Optimally — if the boiler is heated by gas. If an electric heating element is used, then it is better to choose an electric underfloor heating.

To carry out the installation of a water-heated floor in the garage with your own hands, you need to know some of the nuances and points. The most important thing is to form the basis. They are exactly the same as in the case of an insulated floor. The photo below shows how the layers of stacked materials are arranged. It is in this sequence that it is necessary to lay the floor base in the garage with the installation of underfloor heating pipes.

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What is the need for an insulating layer in this design. The thing is that the thermal energy emanating from the heating system will spread in all directions. And down as well. To reduce heat loss, thermal insulation is placed under the heating. Both bulk and slab materials can be used here.

Please note that a concrete screed is poured over the heat-insulating layer. After it dries, a reinforcing frame is laid out on the surface. It is to him that the underfloor heating pipes will be attached using knitting wire or plastic clamps.

In all installation technology, an important point is the choice of the layout of pipes on the floor. The thing is that hot water, having entered the circuit, loses heat as it moves through the pipes. And the farther it is from the boiler, the lower its temperature. Therefore, the best option for laying pipes is a spiral. The photo below shows such a model.

Please note that the half of the circuit, which is considered to be the supply, is located next to the other half — the return. Both parts are laid parallel to each other. Thus, hot water is evenly distributed over the entire garage floor area.

If the garage is small (for one car), then the snake scheme is also suitable. This is the easiest option. The pipe is simply laid with a snake over the entire plane. One end of it is connected to the boiler feed. The photo below shows that the feed circuit is drawn in a straight line to the opposite wall of the garage, where it is connected to the snake.

The second end, being the final element of the pipe structure, is directly connected to the boiler. Please note that the circulation pump of the underfloor heating system is installed precisely on the return circuit near the boiler. Here is the lowest temperature of the coolant. This means that the pump will be subjected to minor temperature loads, which will increase its service life.

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Nesting step

This is an important parameter that varies in the range of 100-600 mm. It is chosen based on the heat load on the structure of the warm floor itself. It depends on the purpose of the room, on the length of the circuit and other factors.

Let’s make a reservation right away that it is impossible to make a bend between pipes laid in increments of 100 mm with a plastic pipe. A bend will occur, which will reduce the diameter of the pipe, which will lead to a decrease in the efficiency of the heating system. Such a step can be used if a copper pipe is used as elements. For plastic, the minimum step size is 150 mm.

The standard laying step is 200-300 mm. But at the walls it is recommended to reduce it to 100-150 mm. The goal is to increase heat transfer near structures connected to the street.

Attention! If the garage area does not exceed 40 m², then the warm floor is laid in one contour. If the area is greater than this value, then there must be two or more contours. This is when two circuits are laid, connected to the heating boiler separately through a comb. In this case, the scheme of each circuit can be the same or different.

Collector-mixing unit

This is the heart of the warm floor. It can be made by hand. But the manifold itself is inexpensive, so don’t reinvent the wheel. Buy a finished design. In this case, the main thing is to accurately select it according to the heat load, in which specialists can help you.

The only thing to note is that it goes to the collector:

• valves or valves on the supply and return circuits;
• air vent;
• drain cock to remove the coolant from the system;
• fittings for connecting pipes to the manifold;
• circulation pump.

Summarizing the topic asked by the question of how to make a warm floor in the garage on your own, it is necessary to indicate that in fact this is not the easiest construction operation. And in many cases, garage owners decide to simply insulate the floors using thermal insulation material. In addition, the underfloor heating system is costly in terms of operation. The consumption of even the cheapest energy source hits the pocket.