Fiber Cement Advances & Drawbacks

Cement siding is durable and fire-retardant. When properly installed, it requires less maintenance than other siding materials and weathers the elements for years to come.

The original formula of 1901, created by Ludwig Hatschek, was called Eternit, which translates to eternity. Yet, fiber cement siding has a long and complicated history, from how it was first created to how it is manufactured today. 

This issue with first-century fiber cement was Ludwig Hatschek formulated his mix using asbestos. Today’s fiber cement uses cellulose instead. Cellulose fiber, primarily wood pulp, is safer and more effective. Current-day cement board poses limited health risks with appropriate mask protection, among other precautions. 

What is Asbestos?

Asbestos is a naturally occurring silicate mineral of long and thin fibrous crystals that was mined rather than manufactured. With a long history of applications, it goes all the way back to the stone age when it was used in ceramics. Even though it was outlawed in the U.S. due to its health risks, it’s still used in construction elsewhere in the world today, with Russia being the largest producer, most recent reports estimating their production at 790,000 tons.

Eternit became widely available in the U.S. by the late 1920s, although it didn’t reach the height of its popularity until the 1940s. Later, it started to fall out of favor in the latter half of the 1960s when asbestos was revealed as dangerous to human health. In the U.S., the first regulations concerning asbestos use started to appear in 1970. But it wasn’t until 1989 that it was ultimately banned from use in the U.S. 

Silica Dust Vs. Fly Ash

Most fiber cement siding is made from a mixture of Portland Cement, ground sand, and cellulose wood fiber. Ground sand, also known as silica dust, can be hazardous to one’s health. When those dust particles are breathed in, they become embedded in a person’s lungs, causing inflammation and scarring. This can lead to complicated health issues, including a condition called silicosis. However, fly ash has its health drawbacks as well. Fly ash particles are a by-product of coal and can induce asthma, inflammation, and immunological responses. Prolonged exposure, such as working in a coal mine, can lead to more severe health issues. 


The only risks associated with fiber cement siding are when cutting into them with an appropriate saw blade for the job. Cutting fiber cement siding can kick up particles in the air and cause personal harm when inhaled. But this is easily avoided when wearing eye protection and a respirator with an appropriate filter. It’s a no-brainer to wear a respirator and eye protection for any significant project, such as cutting into any stone or cementitious material. However, in the event of cutting siding and installing it on your home, it’s always best to leave the installation to a professional authorized dealer.

It’s also worth noting that Nichiha’s proprietary patented formula uses far less silica dust, replacing it with treated, recycled fly ash. As a result, Nichiha’s formula is far less dangerous to breathe than other fiber cement siding. 

For more information, call our technician at Green Acorn.