Owning a car requires not only regular maintenance of the engine, but also the creation of suitable conditions for its storage. Frame garage is an economical and quickly built solution, but without high-quality thermal insulation it turns into a wind-blown structure, where the temperature difference inside and outside is almost absent. That is why the question of how to insulate a frame garage becomes a priority immediately after the construction of the building’s bearing skeleton.
Well-chosen heat-insulating It performs several critical functions. It not only retains heat from heating devices in winter, but also prevents the formation of condensation, which is destructive to metal body parts. In addition, competent isolation allows you to use the room as a full-fledged workshop at any time of the year, providing comfortable conditions for work.
In this article we will analyze in detail the characteristics of various insulation, their compatibility with frame structures and installation features. You will learn why vapor resistance can be the enemy, and cheap foam can be a time bomb, if you do not follow fire safety technologies. Choosing the right solution will save you money on heating and prolong the life of the car.
Requirements for thermal insulation of a frame garage
Frame construction technology implies the presence of voids inside the walls that need to be filled. However, just stuff the first material you get there is impossible, since the garage is a room with an increased class of fire danger and a specific humidity regime. Thermal conductivity The material is a key, but not the only parameter that is worth paying attention to when designing.
The most important aspect is fire safety. The garage stores flammable liquids, and when working with the car, welding or open fire is often used. Therefore, the material must either not burn, or have the property of self-extinguishing. The use of combustible insulation requires mandatory protection with special screens.
⚠️ Note: The use of Styrofoam (EPS) or extruded polystyrene (XPS) inside a garage without protection with drywall or metal profile is strictly prohibited by fire regulations due to the high toxicity of smoke during combustion.
The second critical factor is vapor permeability. The walls of the frame garage should "breathe" so that water vapor formed from the breathing of people, drying out of the car after washing or engine operation, comes out. If you choose a material with low vapor permeability and do not organize forced ventilation, moisture will begin to accumulate inside the walls, which will lead to rotting of the wooden frame and corrosion of the metal.
- 🔥 Fire safety: The material must be in the class NG (non-combustible) or G1 (low-combustible).
- 💧 Wet resistance: The insulation should not lose its properties when wet and promote condensation.
- 🏗️ Stability of shape: The material should not settle or deform over time, leaving voids.
Mineral wool: a classic solution
Mineral wool, made from basalt or fiberglass, remains one of the most popular answers to the question of how to insulate a frame garage. This material is valued for its non-combustible and excellent sound insulation properties, which is important if the garage is in a residential area. Basalt plates have high rigidity, which allows you to install their splinter between the racks of the frame without additional fasteners.
However, the Minwata has a serious drawback - hygroscopicity. The material is able to absorb moisture from the air, while losing up to 60% of its thermal insulation properties in the wet state. To avoid this, installation must be used vapor-insulating membranes from the inside and the windscreen from the outside. Violation of the installation technology negates all the advantages of the material.
Glass, which is a type of mineral insulation, is cheaper, but requires extremely careful handling. Small particles of glass, getting on the skin or in the respiratory tract, cause severe irritation. Therefore, work on the installation of glass wool must be carried out in a full protective suit, respirator and glasses.
Comparison of basalt and glass wool
Basalt wool is more durable, does not crumble and has better environmental friendliness. Glass is cheaper, but it is faster to track and requires complex precautions during installation. For the garage, it's better to pay too much for basalt.
When choosing mineral wool, you should pay attention to the density of the material. For vertical walls of a frame garage, the density of 35 to 50 kg / m3 is considered optimal. Lighter options can slide down over time, forming an uninsulated zone at the top of the wall, and too dense slabs will cost more without a significant gain in heat efficiency.
Polymer insulation: foam and foam
The group of polymer materials includes polystyrene foam (foam) and extruded polystyrene foam (EPPS, foam). These materials are radically different from the minewat by their structure with closed cells, so that they practically do not absorb moisture. This makes them ideal for conditions where contact with water is possible, but poses risks to the microclimate of the room.
The main advantage of EPPS over conventional foam is high mechanical strength and lower thermal conductivity. Plates foamplex It is thinner, but warms better, which saves usable space inside the garage. However, their cost is much higher, and the fuel content remains high. Even samples with flame retardants in direct contact with fire melt and emit a caustic smoke.
Installation of polymer insulation in a frame garage has its own characteristics. Unlike the Minwata, they do not miss steam. This means that the dew point can shift inwards or onto the surface of the walls, causing abundant condensation (the “thermos effect”).
When using foam or EPPS in a frame garage, be sure to organize a powerful supply and exhaust ventilation, otherwise the car will constantly fog and rust.
To reduce the risks when using polymers, it is recommended to combine them with non-combustible materials or use special flame retardant plasters on top of the plates. It is also important to qualitatively seal the joints between the slabs with mounting foam to avoid cold bridges through which heat will go.
Sprayed polyurethane foam (PPU)
Sprayed polyurethane foam is a modern material that is applied in liquid form and instantly foams, filling all the gaps and voids. This is the only solution that allows you to create absolutely seamlessexcluding any bridges of cold. For a framed garage with a complex shape or a lot of communications, this can be an ideal option.
PPU has excellent adhesion to wood and metal, strengthening the structure of the frame. The material does not absorb moisture, does not rot and is not interesting to rodents, which is often a problem for garages. The thermal conductivity coefficient of PPU is one of the lowest among all existing insulation, which allows you to make the walls thinner while maintaining the same thermal characteristics.
The main disadvantage of the technology is the impossibility of self-assembly without special equipment. Application requires a compressor, high pressure installations and experience. In addition, the material is sensitive to ultraviolet light and requires mandatory protection with a finishing finish (plaster, siding or wagging) immediately after application.
| Parameter | Mineral wool | Foam (EPS) | Penoplex (XPS) | PPU (spraying) |
|---|---|---|---|---|
| Thermal conductivity (W/m·K) | 0,035 - 0,042 | 0,038 - 0,043 | 0,029 - 0,032 | 0,022 - 0,028 |
| Fuelsity | NG (not burning) | G3-G4 (fires heavily) | G3-G4 (fires heavily) | G2-G3 (self-extinguishing) |
| Moisture absorption | High. | Low. | Practically zero. | Zero. |
| Vapour permeability | Tall. | Low. | Very low. | Low. |
Ecovata and loose insulation
Ecovata is a cellulose insulation made up of recycled paper with the addition of antiseptics and flame retardants (usually borax and boric acid). This is an environmentally friendly material that perfectly fills hard-to-reach places. With the wet-glue method of applying the ecovat sticks to vertical surfaces and forms a dense monolithic layer.
The advantage of ecovata is its ability to "breathe", regulating the humidity in the room. With increasing humidity, the material absorbs excess moisture, and when drying, it gives them back, without losing its thermal insulation properties. This makes ecowata an excellent choice for creating a comfortable microclimate in the garage.
However, the material has drawbacks. Over time, especially with dry filling, ecowat can shrink up to 20%, which leads to the formation of voids in the upper part of the walls. Also, the material requires protection from direct contact with water and mandatory vapor insulation. Rodents, contrary to popular belief, sometimes start in the ecowat, if the concentration of protective salts decreases.
☑️ Checking the readiness of the frame for insulation
Technology of wall insulation with their own hands
The process of insulation of a frame garage begins with the preparation of load-bearing structures. The wooden frame shall be dry and treated with flame retardants. If you use mineral wool, the first layer from inside the room (warm circuit) is mounted vapor insulation film. It protects the insulation from moist fumes coming from inside the garage.
The stain is then placed between the stains. The width of the plates should be 1-2 cm more than the stride of the racks, so that the material fits tightly to the tree without gaps. If a double layer of insulation is used to achieve the desired thickness, the second layer should overlap the joints of the first, excluding through blowing.
After laying the thermal insulation, a windshield membrane is mounted on top of it (if it was not installed outside before the skin). Then the counter-bar is stuffed to create a ventilation gap, and only after that the finishing finish is attached (gypsum board, OSB, tram). Compliance with the sequence of layers is the key to the durability of the design.
⚠️ Warning: Never press the vapor insulation against the insulation too strongly with brackets or slats without a ventilation gap. This can lead to tearing of the film and violation of the tightness of the contour.
Gate and ceiling insulation
Garage gates and roofs are the areas of greatest heat loss, which are often ignored. The gates are usually metal and have high thermal conductivity. Insulate them best foam or PPU, gluing the plates directly to the metal and closing on top with decorative plating. It is also important to install seals around the perimeter of the flaps.
The ceiling of the garage is insulated on the same principle as the walls, but taking into account the movement of warm air upwards. Here, the insulation layer should be thicker than in the walls (usually 200 mm or more). When using a minewat, it is necessary to protect it from moisture on both sides, since condensation in a cold attic or roof is a frequent phenomenon.
It is critical to ensure a ventilation gap between the roof insulation and the finishing roof, otherwise the wood crate will begin to rot in one season. For pitched roofs, a “cake” scheme is often used, where the insulation is sandwiched between the vapor insulation from below and waterproofing from above.
The quality of garage insulation directly depends not so much on the brand of material, as on the lack of cracks, proper vapor insulation and the presence of ventilation.
Frequently Asked Questions (FAQ)
Can I use foam to insulate the garage if there is a stove?
Styrofoam can be used, but only if it is fully protected with non-combustible materials (for example, drywall sheets or a metal profile). Open foam near fire sources or sparks is a high risk of rapid ignition and release of toxic substances.
Do I need to be insulated with scallop?
Yes, vaporproofing is mandatory. Without it, warm moist air from the garage will penetrate into the minewat, condense inside it when cooled, which will lead to wetting of the insulation, loss of its properties and rotting of the wooden frame.
What is the best thickness for a garage?
For the central regions of Russia, the optimal thickness for walls is 150 mm, and for the ceiling - 200 mm. In colder climatic zones, the thermal insulation layer should be increased to 200 mm and 250 mm, respectively.
Will the garage be protected from rodents?
Not all materials protect against rodents. Minwatu and ecowatu mice can be used for nesting. They chew foam willingly. The best protection is provided by ceramsite (if applicable), a metal mesh built into the structure, or sprayed with PPU that is too hard for rodent teeth.