Exterior walls are fundamental elements of any house, fulfilling both structural and insulating functions, including thermal and acoustic insulation. The construction technologies of single-layer and double-layer walls represent two distinct approaches to building homes. A single-layer wall is simply covered with plaster, whereas a double-layer structure consists of a masonry wall and an insulation layer, typically made of polystyrene or mineral wool.
Using breathable building materials, that do not require additional insulation, is crucial for promoting healthy indoor air quality, as they allow for the circulation and discharge of water vapor, reducing the risk of moisture-related issues like dampness, mold, and rot.
What are the pros and cons of both technologies? Which walls enhance the comfort of residents and contribute to lower bills? And finally, which solution is better; single-layer wall vs. double-layer wall? Find out here!
Breathable walls: advantages of single-layer walls
Single-layer walls made from perlite elements are constructed without joints. In practice, this cuts the time needed to assemble walls and speeds up the whole construction of the house. What else distinguishes the single-layer SYSTEM 3E wall?
A key advantage is the absence of thermal bridges, which directly improve the wall’s insulating properties. Thermal bridges are points through which heat escapes more quickly than through other parts of the wall. The absence of mortar ensures that this problem does not occur when building with 3E technology.
High vapor permeability (so-called breathable walls) is another significant advantage. Perlite structures provide natural air exchange between the interior and the external environment. Low diffusion resistance prevents moisture condensation and moisture-related issues, thereby inhibiting mold growth.
Additionally, walls built from 3E elements exhibit higher mechanical strength due to the absence of joints, which are the weakest part of a wall.
What else should you know about single-layer walls?
The use of ecological materials in building single-layer walls positively impacts both the environment and the health of residents. Relative humidity plays a crucial role in ensuring indoor air comfort. Airborne water vapor can condense to form liquid water when the air is cooled below the dew point temperature. Structures made from natural materials not only help reduce the carbon footprint of construction but also offer cleaner indoor air (free from toxic substances often released by synthetic insulation materials).
Single-layer walls made from natural materials such as expanded perlite are more durable and resistant to external factors. Moreover, the absence of a dew point in single-layer walls is a key benefit as it minimizes the risk of water condensation and mold formation inside the walls due to temperature variations.
Single-layer walls: no additional insulation layer
The lack of issues with the degradation of the insulation layer in single-layer walls is a significant advantage. It is worth noting that the absence of artificial polystyrene insulation helps stabilize how much moisture is present in the insulated building elements.
In double-layer walls, the insulation layer can degrade for various reasons, negatively affecting the wall’s overall properties, including thermal and acoustic insulation, durability, and protection against external factors.
If you are very determined to use additional insulation, mineral wool is much more recommended, because it can dry out and retain its insulating properties after moisture.
Costs and properties of double-layer walls insulated with mineral wool or Styrofoam
Building double-layer walls requires precision and specialized knowledge, especially in installing the insulation and facade layers. This necessity involves hiring specialists. The cost of employing workers comprises several elements, with the most important being labor hours, material costs, and scaffolding (the higher the house, the higher the scaffolding rental costs).
Additionally, the final price is influenced by gluing the polystyrene using special adhesives, smoothing the polystyrene (which requires appropriate weather conditions, potentially prolonging construction time), and protecting the polystyrene from the sun and high temperatures. It is also worth considering spray foam as an option for high moisture exposure due to its strong moisture resistance.
Execution errors, such as improper insulation application or incorrect fastening of layers, can lead to moisture issues, thermal bridges, or even the need for costly repairs.
What to remember when opting for double-layer technology?
Building double-layer walls is more time-consuming than single-layer walls. The need to complete successive stages of work, such as erecting the load-bearing layer, applying insulation, and installing the facade layer, extends the project’s completion time. An example could be a house where double-layer walls with insulation require several additional weeks of work compared to single-layer wall construction.
Finally, there is the risk of insulation layer degradation due to external factors. Making informed decisions about insulation materials, such as comparing mineral wool and spray foam, is crucial to ensure the longevity and effectiveness of the insulation.
Loss of insulation layer properties due to moisture-related issues – key information
Moisture is the primary factor directly impacting the gradual loss of insulation layer properties. The amount of water vapor in the air significantly affects condensation and humidity, which can lead to the degradation of insulation materials over an extended period.
Water can enter the insulation structure due to leaks, condensation from air, and direct contact with water. Moisture absorption by mineral wool reduces its insulating capabilities. What else affects the degradation of the insulation layer?
Insulation materials can become habitats for various pests, such as rodents, which destroy the material’s structure. Pests in insulation create tunnels and free spaces through which heat escapes.
The gravitational sag of mineral wool is another problem in double-layer walls. The insulating material gradually sinks under its weight, meaning the upper parts of the wall are less thermally protected than the lower parts.
During installation or subsequent renovation work, insulation materials can be mechanically damaged. Tears, cuts, or compression of the insulation material can create thermal bridges. Such damage not only reduces the wall’s thermal insulation but also may require costly repairs.
A good example of the loss of insulation layer properties is houses that need partial repairs after several years. In extreme cases, complete removal of the damaged insulation layer made of polystyrene or mineral wool is necessary.
The loss of insulation layer properties leads to decreased building energy efficiency. This results in higher energy demand for heating or cooling the house, translating into higher maintenance costs. Additionally, moisture issues can lead to mold and fungus formation, negatively impacting residents’ health and the building’s structural condition due to the build-up of water vapor.
Single-layer wall vs. double-layer wall – summary
Single-layer walls provide high thermal insulation, leading to energy savings. By minimizing thermal bridges and using high-efficiency thermal materials, houses built with SYSTEM 3E technology have naturally lower energy demands than those built traditionally.
Moreover, the high vapor permeability of single-layer walls maintains a healthy microclimate inside the building. Minimizing the risk of water vapor condensation and mold formation makes the living environment more comfortable and safer for residents’ health. It is crucial to make informed decisions when choosing between single-layer and double-layer walls to ensure the best insulation and moisture management for your needs.
Contact us and start building using SYSTEM 3E
We encourage you to get in touch with us! Our team will thoroughly discuss all aspects of the SYSTEM 3E technology with you and resolve any doubts regarding the design and use of homes built with our technology.
Remember that we do not build only in Poland. In our portfolio, we have realizations in Spain, Portugal, the United Kingdom, Sweden, and even South Korea!