AIRDRIE INSULATION SERVICES
What is Rockwool Insulation?
Fiberglass insulation has been a popular choice for reducing heat transfer through home walls and ceilings for a long time. While it may offer some fire resistance benefits, it may not match the natural capabilities of Rockwool, another commonly used insulation material in residential, commercial, and industrial buildings. To distinguish Rockwool from fiberglass, we can examine its heat retention, fire resistance, moisture resistance, and soundproofing abilities. Keep reading to learn more about rockwool insulation.
How is it made?
Information obtained from the US Department of Energy, sheds light on the process used to manufacture Rockwool insulation and reveals some interesting facts on its remarkable fire-resistant qualities. It primarily consists of basalt rock and slag, a recycled byproduct from steel production, which are superheated until they transform into a molten substance resembling lava. These materials require temperatures exceeding 2,900 degrees Fahrenheit to melt. This mixture is then blown into a spinning chamber, where it is stretched into fibers. These fibers are subsequently compressed into Rockwool insulation slabs. This manufacturing process eliminates all organic matter, significantly enhancing the finished product's resistance to mold and mildew.
The varying statistics regarding the amount of recycled materials in Rockwool insulation can be attributed to the broader category of mineral wool insulation. While Rockwool, as a specific brand of mineral wool, typically contains between 16% to 40% recycled materials according to the manufacturer, the U.S. Department of Energy suggests that mineral wool insulation, on average, contains around 75% recycled materials. This discrepancy arises because the Department of Energy distinguishes between "rock wool" and "slag wool" insulation but doesn't specify the difference in recycled content for each product. This illustrates how the term "Rockwool" is sometimes used generically, blurring the distinctions between products. In general, the precise amount of recycled material in Rockwool insulation varies depending on the specific product. Standard Rockwool insulation may contain 16% to 40% recycled material, while slag Rockwool insulation can have up to 75% recycled material.
How does Rockwool compare to Fiberglass?
Both fiberglass and Rockwool effectively maintain comfortable indoor temperatures throughout the seasons, but Rockwool has a thermal advantage. While fiberglass insulation typically offers an R-value of approximately 2.2 to 2.7 per inch of insulation, Rockwool boasts an R-value ranging from 3.0 to 3.3 per inch of insulation. Unlike fiberglass, which can lose thermal efficiency over time, Rockwool insulation maintains stable thermal performance over the lifespan of a building. As a consequence however, it's worth noting that Rockwool insulation is generally more expensive per square foot than fiberglass insulation.
Rockwool assists in Fire Protection.
As mentioned earlier, Rockwool insulation is composed of materials that must endure extremely high temperatures, exceeding 2,900 degrees Fahrenheit, during the manufacturing process. Consequently, mineral wool products, including Rockwool, can resist fire, flames, and heat up to 1,400 degrees Fahrenheit, with some Rockwool products capable of withstanding temperatures up to 2,150 degrees Fahrenheit without melting, smoking, or catching fire. This impressive heat resistance makes Rockwool ideal for creating fire-resistant barriers within homes, between rooms, and between floors, effectively slowing the spread of fires. In comparison, fiberglass insulation is also highly heat-resistant but begins to melt at around 1,100 degrees Fahrenheit.
How durable is Rockwool?
The durability of Rockwool insulation is indisputable, as it can maintain its thermal efficiency over several decades with minimal degradation in its R-value. This durability is largely attributed to the robust materials used in its production, including rock and steel slag, known for their high durability and resistance to decay and corrosion. The material's longevity is also enhanced by its water resistance, mold resistance, mildew resistance, and fire resistance. The moisture-resistant properties are especially crucial, preventing the insulation from absorbing and retaining water from humid air, which could prematurely damage it.
Rockwool works well for soundproofing.
While Rockwool insulation may be thicker than fiberglass insulation, this thickness aids in slowing the transmission of heat and offers the added benefit of soundproofing. As sound waves attempt to pass through Rockwool, they are slowed and sometimes blocked, providing built-in soundproofing. The density of Rockwool insulation, around 1.7 pounds per cubic foot, is what primarily contributes to its soundproofing capabilities. In comparison, fiberglass insulation has a density of about 0.5 to 1.0 pounds per cubic foot, reducing sound by 4 to 10 decibels, while Rockwool can consistently dampen sound by 10 to 15 decibels.
Where in your home can Rockwool be used and is it mold resistant?
Rockwool's construction and composition make it an excellent choice for rooms with high humidity levels, such as bathrooms and kitchens. Its moisture-resistant and vapor-permeable properties ensure that liquid water drains away from the insulation rather than being absorbed, while gaseous water vapor can pass through without causing dampness. Additionally, being an inorganic material, Rockwool provides an unsuitable environment for mold and mildew growth, as it lacks the organic matter they need for sustenance. Rockwool products are also tested and certified to be resistant to fungal growth, reducing the risk of encountering mold-related issues within walls.