Which insulation is better, polystyrene foam or mineral (basalt) wool??

Selecting the appropriate insulation for your house is essential to guaranteeing cost savings, comfort, and energy efficiency. Two well-liked choices stand out when it comes to insulation materials: mineral wool (basalt) and polystyrene foam. Each has a unique set of benefits and possible drawbacks, which adds to the difficulty of choosing.

Many homeowners favor polystyrene foam because of its superior thermal insulation qualities. In addition to being lightweight and simple to install, it offers excellent energy efficiency. Mineral wool, also known as basalt wool, on the other hand, provides better sound and fire resistance. Being composed of recycled materials and natural stone, it’s also a green choice.

Making an informed decision can be aided by being aware of the main distinctions between these resources. Your selection will be heavily influenced by elements including price, installation method, durability, and the particular insulation requirements of your house. You can compare mineral wool and polystyrene foam in these areas to find the insulation that best suits your needs and guarantees a cozy home.

Advantages and disadvantages

So let’s compare stone wool and polystyrene as two types of insulation to see which is superior. Prior to delving deeper into a more thorough analysis of individual attributes, we will first ascertain each material’s quality indicators.

The internal structure and manufacturing technology of expanded polystyrene and mineral wool are entirely dissimilar. Natural stone is melted and fluffed to create basalt mats, while a chemical reaction produces EPS slabs.

Extruded polystyrene foam

Using an extruder, foamed styrene is formed into flat, rectangular slabs to create this kind of foam. Because the final products have a porous structure with 96–98% tiny voids filled mostly with carbon dioxide and a tiny bit of air, expanded polystyrene performs well as insulation.

• thermal conductivity coefficient – ​​0.028-0.042 (W/m*K);
• moisture absorption when immersed in water for a day – 2-4%;
• compressive strength when reaching 10% deformation – 0.05-0.2 MPa;
• mechanical bending strength – 0.07-0.35 MPa;
• density – 20.0-50.0 kg/m3 .

The various brands of PPP that are produced are linked to the disparities in indicators. Denser and stronger materials are said to have higher performance.

Advantages:

• excellent insulating qualities, increasing with increasing foam density;
• long service life reaching 50 years;
• operating temperature range from -50°C to +75°C (with a maximum permissible +160°C);
• flame retardant ability;
• low cost;
• easy installation (using glue and plastic nails);
• low density, which does not weigh down building structures;
• inertness to the effects of cement-based liquid solutions;
• good adhesion to plaster solutions and paints and varnishes;
• is not affected by mold and mildew even with constant exposure to moisture.

Minuses:

The requirement to test PPS boards for flammability is a significant drawback. The truth is that some of these foams, which are classified as G3, have the ability to catch fire. However, polystyrene becomes a self-extinguishing material of class G1 when fire retardants are added.

As a result, you must light a portion of the stove when making a purchase. The burning should end in four to five seconds. Such thermal insulation cannot be used to insulate the facade if this does not occur.

Additionally, PPS slab detractors point out:

• release of styrene when heated above 30°C and in the absence of a continuous surface coating;
• release of hydrocyanic acid, phosgene and other toxins when melted under the influence of an open flame;
• ability to be destroyed under the influence of certain types of paints and glue;
• ability to resonate and transmit noise and vibration vibrations;
• aging under the influence of solar ultraviolet radiation.

One of the materials that rodents prefer is foam. Consequently, there needs to be additional protection against their influence for the lower portion of the thermal insulation coating.

Basalt wool

Thin fibers taken from molten basalt are used to form mineral wool slabs, and they are fluffed with a strong air flow. After that, a press is used to compress the fiber mass until the desired density is reached. Insulation with:

• thermal conductivity coefficient – ​​0.035-0.045 (W/m*K);
• moisture absorption when immersed in water for 24 hours – 1-2%;
• compressive strength when reaching 10% deformation – 8-60 kPa;
• mechanical bending strength – 0.12-0.16 MPa;
• density – 30-40.0 kg/m 3 .

The fact that there are multiple brands of mats manufactured from basalt fibers accounts for the variance in the specified technical attributes.

Positive characteristics

Pros list the following as some of the key benefits of mineral wool:

• durability exceeding 50 years, but this is only a statement by the manufacturers, since the production of the material lasts no more than 25 years;
• excellent thermal insulation qualities;
• non-flammability and ability to withstand heating up to 1100°C;
• lack of hygroscopicity;
• resistance to aggressive chemicals;
• high elasticity;
• environmental cleanliness and safety;
• simple installation technology;
• resistance against fungus, mold and rodents.

Drawbacks:

The primary drawback of basalt mats is their expensive production, which also requires a lot of energy. It should be mentioned that a significant amount of dust is produced when the heat-insulating layer is installed.

Comparison of characteristics

When evaluating the superiority of mineral wool versus polystyrene foam as insulation, it is important to take into account various fundamental technical and functional aspects.

• environmental cleanliness;
• thermal conductivity;
• lifetime;
• ease of installation;
• resistance to biological effects;
• price;
• insulation density;
• water absorption;
• strength;
• Fire safety;
• soundproofing properties.

Which is more environmentally friendly?

Both insulation materials are completely safe for human health when used as intended. However, polystyrene foam can become hazardous when exposed to an open flame or when the temperature rises.

Toxic and poisonous gases are actively released when polystyrene melts. Thus, it is illegal to use PPS boards for insulation in the majority of European nations. Though it’s widely used in our nation.

Which retains heat better?

Excellent thermal insulation properties are possessed by both types of insulation. However, it is evident from a comparison of the thermal conductivity coefficients that polystyrene foam is a more effective insulation material.

Which is cheaper?

Basalt mats can be purchased for 1400–2300 rubles per square meter. The price range for expanded polystyrene is 1900–2300 rubles. /m 3, meaning that the cost is nearly the same. However, as was already mentioned, polystyrene foam will require 40–50% less because it is warmer. PPS slabs turn out to be less expensive than mineral wool.

Which will last longer

Regarding the technical specifications, it was previously mentioned that basalt wool has a 50-year service life and PPS slabs have a 25-year service life. Cotton wool is the obvious front-runner here. However, you should consider the finishing technique when selecting insulation. Therefore, a facade plastered with the "wet" method is only going to last 25 years or so. It therefore makes no sense to use pricey, durable wool.

The easier it is to insulate

Both insulations are installed using the same technology. First, the insulation is glued in place, and it is then further secured with plastic "mushroom" style nails.

What is less attractive to pests

Mold and mildew cannot grow on mineral wool or polystyrene. However, rats willfully dig burrows in polystyrene foam, which is noticeably less effective than basalt fibers in this regard.

Other criteria

When selecting insulation, it is advised to consider the following comparative qualities:

• polystyrene foam is much lighter than mineral wool;
• expanded polystyrene absorbs moisture less and does not lose its properties when wet;
• basalt mats have greater bending strength, which makes it possible to insulate surfaces with complex configurations;
• the fire protection characteristics of polystyrene foam are significantly lower than those of its competitor;
• Polystyrene has virtually no vapor permeability.

The insulation options you have for your project will determine whether to use mineral wool or polystyrene foam. If moisture resistance and thermal efficiency are your top priorities, polystyrene foam is a great option. Many builders and homeowners find it to be a convenient option due to its lightweight design and simplicity of installation.

However, mineral wool is unique in that it can effectively block out fires and reduce noise. If your main concerns are safety and noise reduction, mineral wool might be a better choice. It’s also a more environmentally friendly option because it’s frequently constructed from recycled materials and gives buildings good breathability.

In the end, each material offers benefits and drawbacks. Your choice should take into account various aspects, including your personal preferences, building requirements, climate, and budget. Seeking professional advice can also yield insightful information customized to your unique circumstances.

You can choose an insulation type that best suits your home or project’s needs for comfort, safety, and energy efficiency by being aware of the distinct advantages of each type. Whether you choose mineral wool or polystyrene foam, making an initial investment in high-quality insulation will yield long-term benefits.

It’s important to take your priorities and individual needs into account when choosing between mineral wool and polystyrene foam for insulation. Although polystyrene foam is lightweight and provides good thermal insulation, it can be less environmentally friendly and is not fire resistant. Mineral wool, on the other hand, is more sustainable, offers better fire resistance, and is made from recycled slag or volcanic rock. However, it can be heavier and more difficult to install. In the end, the optimal decision will depend on your priorities: environmental impact and fire safety, or simplicity of installation and effective insulation.

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