Is it necessary to insulate a gas block (a house made of aerated concrete) 300 and 400 mm and, if necessary, with what material

Selecting the appropriate building materials is essential to guaranteeing durability, energy efficiency, and comfort. Gas block, or aerated concrete, is one well-liked choice. This material has excellent insulating qualities, strength, and light weight. But many homeowners question whether they really need more insulation, particularly when using blocks that are 400 or 300 mm thick. A house’s long-term performance can be greatly impacted by knowing how important insulation is and what kind of materials to use.

Gas blocks naturally insulate against heat thanks to their special structure, which is packed with air pockets. Even so, especially in colder climates, they might not always offer enough insulation on their own. The choice to add more insulation is influenced by a number of variables, including building codes, the local climate, and energy efficiency objectives. More insulation can frequently help a building perform better thermally, which lowers heating and cooling expenses and creates a cozier interior atmosphere.

Aerated concrete walls can be insulated using a variety of techniques. Extruded polystyrene (XPS), expanded polystyrene (EPS), and mineral wool are examples of common materials. Every material has benefits and is selected according to criteria such as cost, moisture resistance, and thermal resistance. For example, EPS and XPS provide good thermal insulation and moisture resistance, while mineral wool is well-known for its exceptional fire and sound insulation qualities. Making the correct insulation material choice will optimize your home’s comfort and energy efficiency.

In conclusion, even though gas blocks already provide reasonable insulation, it can still be helpful to add another layer, particularly in areas with extreme weather. Proper insulation not only boosts a home’s thermal efficiency but also lowers energy costs and increases comfort. With careful consideration of the insulation’s type and thickness, homeowners can make sure their gas block homes are equipped to withstand a wide range of weather conditions.

Factors contributing to condensation

When considering whether an aerated concrete home needs insulation, it is a good idea to familiarize yourself with the theory. Because air pores are built into the structure of aerated concrete, the material itself retains heat well. However, installing a heat-insulating layer is necessary to guard against moisture, which can quickly destroy the entire structure, in addition to providing insulation and reducing the need for heating in the future.

After all, aerated concrete is hygroscopic, it strongly absorbs water, which then, when frozen, leads to deformations and the spread of cracks. This can only be avoided thanks to insulating and finishing materials that can provide reliable protection of blocks from moisture.

• High humidity inside the premises under conditions of low temperatures outside. So, moisture can appear during the construction process, but it evaporates throughout the year due to ventilation and vapor permeability of finishing materials (so that moisture is not “locked” inside the walls).
• Insufficient heat transfer resistance of the walls – with errors in the choice of material or its thickness (even if the room is warm due to heating).
• The appearance of "cold bridges"-zones with low heat-insulating ability due to the presence of metal anchors, laying blocks on a cement mortar.
• In case of violation of construction technology – if there are cracks in the insulation, due to poor quality filling of vertical joints with glue, etc.d.
• When moisture is trapped inside.

The final scenario, which is the most challenging, occurs when a material with a high vapor permeability index is exposed to a material with a low vapor permeability level on the exterior.

This reduces the thermal insulation qualities of the wall and increases the likelihood that the structure will freeze in the future because the water vapor cannot escape outside and is absorbed into the wall.

The best choice for insulation for aerated concrete is mineral wool, vapor-permeable paints, and plasters. Keep this in mind when installing thermal insulation and cladding: the closer to the outside, the higher the vapor permeability should be. The greenhouse effect manifests itself otherwise.

Calculation of the dew point for the walls of your cottage

Dew point calculations are crucial because they provide a temperature indicator that allows you to pinpoint the precise moment at which steam reaches maximum saturation and starts to condense into water droplets. It will be feasible to accurately calculate the ideal insulation level and wall thickness with the help of this value.

When proper calculations are made in high-quality housing, dew drops—drops of water on the windows that appear when the outside air temperature suddenly changes—can also be seen. Condensation appears on windows when there is a temperature differential of minus outside the window and +20 inside the apartment. Furthermore, the amount of humidity in the space is crucial (as evidenced by breathing, cooking, outdoor humidity, etc.).

Moisture that collects on the glass can be wiped off, but once dew gets inside the aerated concrete because of improper calculations or material selection errors, it cannot be removed and destruction cannot be prevented. There will be a temperature in the wall where steam starts to condense and turn into water when the outside temperature drops below zero. It is crucial to locate the dew point and construct the walls such that it is outside rather than inside.

The dew point is determined by accounting for various factors, including wall thickness, material grade, indoor and outdoor temperature, and indoor humidity. Keep in mind the partial pressure, also known as vapor pressure; in a frosty environment, this indicator is low, and in a warm environment, it is higher. Where there is less pressure, that is where the steam wants to escape. As a result, the dew point in D500 aerated concrete blocks with a 40-centimeter thickness will be closer to the wall’s exterior during the winter.

The possibility of freezing due to moisture is eliminated when a vapor-impermeable film is laid inside the room using mineral wool with a thickness of 10 centimeters and the same initial wall data. Correctly chosen insulation will have its dew point in its thickness rather than in the wall.

The dew point can be determined using specific online calculators, formulas, and the values of particular materials. However, it is much simpler to simply follow the fundamental guidelines and recommendations of the experts: insulation is required for walls smaller than 300 millimeters, while a 400 millimeter wall is sufficient for the middle zone.

While insulation is required in northern regions, it can be used sparingly or the thickness of the walls can be decreased in southern regions (assuming thermal insulation is present).

What wall design is optimal in terms of cost and risk minimization

Contrary to assertions that aerated concrete doesn’t require insulation, thermal insulation is typically used in residential construction before a facing layer is added. By choosing this option, you can save money on heating in the future and have faith that the building will remain sturdy and reliable because moisture won’t destroy it. The two most widely used insulation materials are expanded polystyrene and mineral wool.

Insulation with mineral wool

A fibrous insulation of inorganic origin is called mineral wool. The material is composed of glass, binders, and different types of rocks. Wool’s fibrous structure helps to retain air in its thickness, which insulates the room from the cold and serves as a high-quality, reasonably priced insulation.

• Long service life – 25-40 years.
• Environmentally friendly and safe for human health due to the absence of hazardous synthetic components in the material.
• Non-flammability and no smoke formation under an open fire, which is extremely important for residential buildings.

• Low level of hydrophobicity – wool does not absorb moisture at all, but removes it to the outside.
• Chemical and biological resistance, inertness.
• Low level of deformation – the insulation does not lose its original shape over time.
• Good vapor permeability (which is important for walls made of gas blocks, which cannot be finished with impermeable materials, thereby causing moisture retention inside).
• Universality as isolation material – not only retains heat, but also does not allow sounds.

Mineral wool has been utilized for insulation for a long time and has proven to be a great material that is affordable, simple to install, and fully capable of handling its tasks.

• D300 (wall thickness 20 centimeters) and mineral wool 5 centimeters thick.
• D400 (20 centimeters) and minvat 10 centimeters.
• D400 (30 centimeters) and mineral wool 5 centimers.
• D500 (20 centimeters) and minvat 15 centimeters.
• D500 (30 centimeters) and minvat 10 centimeters.
• D500 (40 centimeters) and minvat with a layer of 5 centimeters thick.

These are viable options for Russia’s central regions. The values are higher in the northern regions and lower in the southern ones.

Insulation with polystyrene foam

Expanded polystyrene, also known as extruded foamed polystyrene, is supplied in slab form with a closed pore type and a dense cellular structure. This is what gives polystyrene its strength and moisture resistance. Typically, the material is used to insulate basements, roofs, and foundations. However, because it will lead to moisture buildup, it is best to avoid covering aerated concrete walls from the outside with this heat insulator.

Notwithstanding the material’s shortcomings, aerated concrete nevertheless uses it because of its many benefits, including low cost, simplicity and ease of installation, high heat-saving qualities, durability, and the ability to shift the dew point outside of the walls. Expanded polystyrene can be used to insulate aerated concrete walls, and installation only requires calculations, sheet purchases, cutting, and screw fastening.

Expanded polystyrene sheets have a thickness of 2 to 10 centimeters; if required, they can be adhered twice as thick. Additionally, you can order individual panels from the factory that are the necessary thickness. Sheets of gas concrete measuring 30 centimeters by 10 centimeters are sufficient for a house; the insulation will come with all the required heat insulation indicators.

Main conclusions

We can make several significant inferences from the characteristics of gas block walls and the requirement for insulation, which should be used as a basis for planning, carrying out calculations, and constructing.

• If D500 blocks are used in construction and the wall thickness is 30-40 centimeters, then a layer of insulation for living space is mandatory. A 5-centimeter layer of mineral wool or 10 centimeters of expanded polystyrene is sufficient.
• Expanded polystyrene is less preferable than mineral wool, since it is a vapor-impermeable material and, if the dew point is incorrectly calculated, can cause moisture to accumulate inside the blocks.
• Walls built from D400 gas blocks 40 centimeters thick in central Russia do not need to be insulated.
• The vapor permeability of materials should increase from the inside out.
• The preferred cladding option is ventilated facades, subject to the quality of the material, the walls do not need additional insulation.
• To reduce heat loss, it is necessary to follow the construction technology – lay the blocks on glue, do not use through fastenings with metal anchors (to eliminate the appearance of cold bridges).

The thickness of the walls is an important consideration when determining whether to insulate a home constructed of gas block or aerated concrete. Insulation is typically advised for walls 300 mm thick or thicker in order to improve thermal efficiency. On its own, this thickness might not be enough to provide adequate insulation, particularly in colder climates. Insulation keeps the house cooler in the summer and minimizes heat loss in the winter, helping to maintain a comfortable indoor temperature and lowering energy costs.

The need for extra insulation for 400 mm thick walls may vary depending on the particular climate and energy efficiency objectives. This thickness might provide sufficient thermal insulation in milder climates without the need for additional layers. To guarantee comfort and energy savings, even 400 mm walls in areas with severe winters can use more insulation.

Selecting the appropriate insulation material is essential for best results. Materials with exceptional thermal qualities and durability, like mineral wool, polystyrene, or polyurethane foam, are frequently utilized. Each has benefits and uses that vary based on the desired degree of insulation and available funds. When choosing an insulation material, it’s crucial to take the environment and moisture resistance into account.

In the end, insulating a gas block house can improve its longevity, comfort, and energy efficiency considerably. Long-term savings on energy costs and a more stable interior environment make it a worthwhile investment. Getting professional advice can help you decide which insulation plan is best for your climate and situation.

For the best energy efficiency and comfort when building with aerated concrete blocks, which are usually 300 to 400 mm thick, insulation may still be required. Even though aerated concrete has good thermal qualities, particularly in colder climates, adding insulation can further improve the warmth of the home by reducing heat loss. The selection of insulation material is influenced by various factors, including cost, environmental impact, and ease of installation. Mineral wool, polystyrene, and polyurethane foam are common choices that provide varying degrees of durability, moisture resistance, and insulation.

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Gleb Grinfeld about construction: is it necessary to insulate a house made of aerated concrete? // FORUMHOUSE