The composition of fiber cement board siding affords this exterior building material several unique properties. Aside from fiber cement, homeowners have a choice among manicured stone, genuine wood, acrylic vinyl or weather-resistant metal siding when renovating a home. Fiber cement manufacturers fabricate this product by utilizing a similar process, but the constituent materials vary from company to company. If properly installed, fiber cement siding can extend the lifespan of a home’s exterior cladding for decades.

Fiber Cement’s Ingredients

Fiber cement board siding primarily consists of cement, cellulose fibers and sand, according to the Portland Cement Association. This organization studiously provides American and Canadian cement manufacturers the opportunity to provide fair and accurate information and research regarding fiber cement and cement-related products.

The main ingredients in fiber cement are Portland cement and Calcium Silica (sand). Portland cement is the most common type of cement used in the world due to the material’s versatility. Cellulose fibers compromise as little as 10-15 percent of the composition of fiber cement. Cellulose fiber prevents the siding from buckling and cracking under environmental stress caused by changes in weather.

One popular manufacturer’s best-selling, medium-density fiber cement siding consists of approximately equal parts of cement and sand. On the other side of the quality spectrum, low-density fiber cement siding contains more sand than cement. Some low-density products contain as much as 60 percent sand by weight, for instance.

Fabricating Fiber Cement Siding

The fabrication and curing process of fiber cement is essentially the same across all manufacturers. Specifically, fiber cement manufacturers deploy a steam curing technique known as autoclaving. This method gives fiber cement its strength and dimensional stability. Cellulose fibers are then added to hold the material together, which aids in preventing splitting and cracking.

This fabrication process allows fiber cement to be manufactured in layers. Thickness and density of the material varies based upon the number of layers each manufacturer utilizes. Lastly, fiber cement undergoes a high pressure molding process after shaping that allows manufacturers the opportunity to cut their products into virtually any shape imaginable.

The End Results of Fiber Cement

At the end of the day, fiber cement board is a versatile, durable and affordable exterior building material. Fiber cement siding can mimic all-natural wood siding, but unlike wood, fiber cement does not rot or become infested with parasites such as termites. From an economical perspective, fiber cement siding costs far less than stone masonry or wood siding. Functionally, fiber cement board siding trumps vinyl and wood siding in durability testing, so homeowners interested in an economical exterior siding solution ought to take a close look at fiber cement.