Drywall is a popular building material used for constructing walls in homes and commercial spaces, serves as an economical alternative to traditional plaster. Recognizable for its white, rock-like panels covered with paper, drywall is the go-to choice for residential wall coverings. It’s worth noting that handling drywall during installation necessitates wearing a safety mask to prevent inhaling potentially harmful fine dust.
In 1916, the U.S. Gypsum Company introduced drywall to the world. Its precursor, plasterboard, had been manufactured as far back as 1888 in Kent, England. The U.S. Gypsum Company revolutionized the product by incorporating wrapped paper edges and coining the well-known name “Sheetrock.”
Initially, drywall faced moderate success, as traditional plaster wall construction remained favored by most builders. However, after World War II, during the post-war economic boom of the late 1940s and 1950s when numerous homes were rapidly built, drywall became the standard for residential wall construction. Hanging drywall is now the predominant method for finishing wall surfaces.
WARNING
It’s imperative to wear a mask when working with drywall, and ensure that the mask is rated for dust particulates.
What is Drywall Made of?
Drywall primarily consists of gypsum plaster, along with cellulose or fiberglass. Drywall panels, also referred to as wallboard, plasterboard, gypsum board, or Sheetrock, are produced by sandwiching a core layer of wet gypsum plaster between heavy paper or fiberglass surface sheets, which are then solidified in drying chambers. Once dried, the material becomes sturdy and rigid, making it ready for use as a building material.
Cellulose or Fiberglass
Up to 10% of the composition of drywall is comprised of cellulose, present in the paper facing on both sides of the panel. However, an increasing trend is the use of mold-resistant fiberglass for facing drywall, as seen in products like USG Sheetrock Mold Tough and GP’s DensArmor Plus. When using fiberglass joint tape like FibaTape, you’re essentially using the same material for facing mold-resistant drywall panels.
Gypsum Plaster
Gypsum accounts for 70% to 90% of the drywall’s composition. This mineral, known as calcium sulfate, is affordable to mine, fire-resistant, and offers excellent sound-deadening properties. However, the rock-like material in drywall panels is more accurately described as gypsum plaster.
Fire-rated type X drywall includes added fiberglass with the gypsum. Unlike asbestos, which is known to cause the fatal illness mesothelioma, gypsum dust is not a serious health hazard.
Additives
Although gypsum forms the majority of drywall panels, various additives are included in the manufacturing process. The process begins by heating raw gypsum powder to remove water, followed by slight rehydration and mixing with different fibers and additives. These additions enhance strength, accelerate hardening, prevent mildew and mold, and offer other benefits. While these materials are present in small amounts by volume, they are crucial for creating the gypsum plaster core of drywall panels:
- Paper or fiberglass fibers
- Plasticizers
- Starch
- Finely ground mica crystal as an accelerant
- EDTA or other chelating agents
- Anti-mildew agents, such as boric acid
- Wax emulsion or silanes to reduce water absorption
- Potassium sulfate
What is Joint Compound Made of?
In addition to large drywall panels, the wall system relies on joint compound, or mud, for sealing the joints between panels. Despite its appearance when dry, resembling gypsum, joint compound is not a liquefied gypsum material. The composition of drywall mud includes:
- Calcium carbonate: The primary mineral in drywall mud, also known as ground limestone.
- Talcum: Ultra-fine talcum powder, similar to that used in baby powder, is a key component. By volume, talc makes up 5% to 15% of the joint compound and helps achieve a smooth, crack-resistant finish.
Are there Harmful Chemicals in Drywall?
When drywall is stable and not producing dust, it is safe. However, as with any material that generates dust and fine particulates, precautions must be taken to avoid inhaling drywall dust. This fine dust contains carcinogens such as formaldehyde, acetaldehyde, and crystalline silica, which can be harmful when inhaled.
Concerns about unsafe drywall primarily center on hazardous chemicals found in drywall panels manufactured in China. For instance, sulfur has been detected in Chinese drywall but not in most U.S.-made drywall. Elevated levels of sulfur in drywall have been linked to corrosion of electrical wiring and plumbing pipes.
Strontium is present in both Chinese and U.S.-made drywall, although the concentrations are notably higher in Chinese products. Some drywall products contain agents to combat mold and mildew, which can pose challenges for individuals with sensitivities.
FAQ
What is the difference between drywall and Sheetrock?
Sheetrock is a popular brand name for drywall gypsum panels, produced by the USG Corporation (U.S. Gypsum Corporation).
What is the most commonly used drywall?
White Board or regular drywall is the most popular choice, typically in 4-foot by 8-foot panels with a thickness ranging from 3/8-inch to 1-inch.
What is waterproof drywall called?
Waterproof drywall is known as Green Board drywall, which features a water-resistant coating and chemicals resistant to moisture and mildew.
tag: # what is drywall made of
