Gypsum Board As A Building Material

Introduction

Gypsum also known as drywall is a building material that is commonly used for interior walls lining. The gypsum board is also known by other names like wallboard, plasterboard, or Sheetrock. Its features like the paper facers and noncombustible core makes it different from other types of building materials used in interior walls lining like hardboard, plywood, and fiberboard. It is made by placing a gypsum composed plaster between two paper layers. The gypsum is mainly a monoclinic mineral that is extracted from sedimentary rocks. In order to foster mixing of the plaster at times fly ash is used to make the mixture. This is mainly a by-product extracted when burning coal and it’s used as an additive for various types of products. Once the mixture of gypsum is put between two pieces of paper the board is heated with a flame to make a strong board. This results in a drywall that can be cut into different size to be used for building construction. Gypsum has been in use for a long period as standard material for ceiling and wall finishing. They are also considered for exterior use because of its feature as a fire resistant material. It’s used in buildings to control sound flow through floors, walls, and ceilings. Innovation in gypsum manufacture has also helped to meet green building requirements as the demand for environmental friendly construction continues to rise. Gypsum is one of the major inventions in the construction technologies. This paper reviews use of gypsum as a building material.

Brief History

In construction of structural walls there has been a remarkable improvement in building technologies. In the ancient Egypt building materials like plaster and stucco were commonly used. In North America, up to 1950s, materials commonly used for interior linings were mainly plaster and lath. However, drywall became popular in the 50 as the best for interior construction. Unlike plaster it offered several advantages like it ease of installation and the fact that unlike plaster it does not crack (Partridge, 2012).

According to Haun, Laurence, & Snyder (2002) there is a possibility that drywall was used for interior construction before Second World War, but it was not very popular. Its popularity in United States as a building material for interior walls can thus be traced back to 1950s. During this period it became the preferred building material for residential houses. Its entry into the market pushed out other materials used for wall construction like plaster and lath. Plaster lost to drywall because it took a longer period covering the wall with it usually 2 to 3 weeks. Beside, after the entire process the house frame were usually left waterlogged. In addition, during the cold winter it took the house a month or more to completely dry. More so, cabinets that were installed after plastering tended to develop sticky drawers. Passage doors on the other hand, were difficult to open, and there was also expansion and buckling of hardwood floors. As a result, the construction industry decided to switch to the drywall technology instead as the preferred building material (Haun, Laurence, & Snyder, 2002).

How it is made/manufactured

Gypsum core is made up of mineral called gypsum extracted from sedimentary rocks. Gypsum is a mineral comprising of calcium sulfate that exists in crystalline form. The molecular formula for the mineral is CaSO4.2H20. This means that a 100 pounds of the gypsum rock consists about 21 pounds of chemically combined water. Manufacturers mine the gypsum rock and transport it to their facility for manufacturing. There the rock is crushed and grounded to the fineness of flour. This flour is them roasted or calcined at a temperature of 350 degree to preferentially discharge some of the water in the form of steam. The roasted gypsum also known as hemihydrates is again mixed with water and placed between two special types of paper to create the gypsum wallboard panel (Spence, 2008). The mixture of calcined gypsum with water is slurry, which is poured in a continuous layer of paper held by a board machine. As the conveyor machine moves the board downwards, calcium sulfate rehydrates or recrystallizes, it combines with water in a chemical process reforming itself into the original rock state. The paper used is both chemically and mechanically enjoined o the core. Once this process is done the board is cut into different lengths and passed through a dryer to remove any moisture that exists (Gypsum Association, n.d). Notably, a smooth white paper is fitted on the good side of the panel to make it easier to absorb paint. The other side comprises of rough, dark colored, porous paper surface. The panels are packed in pairs.

Manufactures can also use synthetic gypsum or flue gas desulphurization to produce the gypsum board. This is made in electricity plants that have a system in place capable of separating sulfur dioxide among the flue gases. This type of a system comprises of scrubbers fitted with calcium carbonate or limestone to chemical combine or absorbs sulfur dioxide before it is discharged to create gypsum or calcium sulfate. The synthetically made gypsum from the electricity plants is transported to the facilities of the gypsum wallboard manufacturers. The process of making the synthetic gypsum is similar to that of mined gypsum with the only difference being that in this case there is no need for crushing.

It is made in different sizes. The standard size of the panel is a 48 inches panel. The most common sizes used in houses construction are 8 and 12 ft. The common thickness for many gypsum wallboard panels is ½ inch. These are the common sizes for the ceiling because they do not sag.

Different types/uses of gypsum board

Gypsum board technologies continue to evolve enabling manufacturers to produces different product varieties used for various purposes. These includes applications as interior walls, bases for ceramic, ceilings, exterior sheathing and soffits, plastic and metal tiles area separation firewalls, shaft enclosures and as fire proof layers for structural elements. Gypsum boards are available in different thickness for various applications. A ¼ inch board is used in exterior walls to improve sound control and in ceilings for curved surfaces and remodeling. A 5/16 inch board is used in sound control and production of manufactured houses. A 3/8 inch gypsum board is used for remodeling and repair as double-layer system. A ½ inch board is uses as a single layer ceiling material for residential construction and as double-layer system in improving fire and sound ratings. A 5/8 inch board is used both as a double and single layer wall system. Its greater thickness improves fire resistance, makes for better resistance, and higher rigidity. Lastly, there is ¾ and 1 inch board used for shaft walls, interior partitions, chaseways, stairwells, corridor ceilings, and separation firewalls (Gypsum Association, n.d).

Besides thicknesses gypsum boards are also categorized into different types. Regular types are popular for ceilings and interior walls finishing. It is capable of controlling sound and fire protection. Regular gypsum wallboard have different thicknesses with ¼ to 3/8 inch boards being used for remodeling works, curved walls, and double layer installations. There is also ½ to 5/8 inch regular board used for ceilings and interior walls. A second type is the fire-resistant gypsum wallboard. It is known as Type-X panel. The paper covering it from edges and back comprises of additives that enables it to prevent fire. It is used to prevent spread of heat to structural embers. Its core comprises of moisture, which evaporates if the panel is heated. This delay the heat passage until all moisture is lost. It also comprises of non combustible fibers that can continue to hold the fire even when all moisture is lost. Installing several layers of this board can delay the time taken for fire to spread. It’s usually used in construction of walls separating a house from a garage or just in usual apartment walls (Spence, 2008).

A third type is moisture-resistant gypsum. The gypsum core is specifically manufactured to act as the base for ceramic tile installation as well as other nonabsorbent finish material in walls. Its core is specifically made to endure impacts of humidity and moisture. There is also a fourth type known as water-resistant gypsum wallboard. Its core is water resistant. Other types includes ceiling wallboard that has a core capable of preventing sagging, flexible gypsum drywall designed for use in curved surfaces, vinyl-surfaced gypsum that comes with different patterns and colors to avoid further finishing work and finally there is high-impact gypsum board used where the wall is likely to be exposed to infrequent penetration or impact (Spence, 2008).

Estimating

It is important to know the amount of materials needed before installing the gypsum wallboard. This will help to minimize time required to run back to the suppliers of materials. It also tells a constructor the time need for a specific job completion. It is also important in order to estimate the total cost of the project. There are certain basic steps that must be followed to estimate the cost. First the constructors should be able to tell the number of wallboard that must be used for the job. This is determined by the panel pattern selected and the size to be placed on each wall. Then estimate the number of nails to be used, which is calculated per panel. Then consider the number of screws to be used. Then determine the size of tape to be used. 100 square feet of gypsum wallboard can use 380 lineal feet of tape. The cost is also affected by the number f corner beads to be used. Each corner uses one bead. Then consider the joint compound. Different manufacturers’ compound can influence amount needed for a specific job. Lastly, the cost of adhesive also influences the cost of the project (Spence, 2008). The labor cost for installation of gypsum board is estimated using square foot.

Chinese drywall

This term is used to indicate environmental health impacts associated with defective drywall that are made in China and shipped to United States. The term gained popularity in 2009. People using these drywalls for their home construction started to report problems like electronic equipment destruction, and health problems like allergies. In contrast, the United States manufactured drywall is reported to meet environmental standards of providing healthy air at homes, hospitals, schools, and in other buildings (National Gypsum, 2011). The Chinese drywall is associated with emission of sulfides that causes the negative health impacts. United States manufactured drywalls have similar compounds like the Chinese drywalls. However, in comparing drywall made in U.S to that of China, laboratory test indicate that the latter has significant proportion of pyrite. It is this pyrite that is attributed with production of sulfur compound due to oxidation. Hydrogen sulfide is attributed to corrosion of copper materials in the homes (Franck & Franck, 2012).

Sustainability

Use of synthetic gypsum is a good way to protect the environment. The impact of gypsum on environment includes disruption of habitat due to mining, emissions during processing and shipment as well as energy use and solid waste generation due to disposal. The use of synthetic gypsum can reduce some of these negative environmental impacts. Because of advancement in technologies manufacturers can now produce more environmental friendly boards. One such product is the EcoRock drywall. It is made from 80 percent of material recycled from industry by products, uses waste materials from cement and steel plant. And can easily be disposed in landfills. It is dried and cured naturally, therefore, uses less energy than in traditional method of processing (Kubba).

References

Franck, H. & Franck, D. (2012). Forensic Engineering Fundamentals. Florida, FL: CRC Press.

Gypsum Association. (n.d). Using Gypsum Board for Walls and Ceiling Section 1. Retrieved on Nov 12, 2013 from: http://www.gypsum.org/using-gypsum-board-for-walls-and-ceilings/using-gypsum-board-for-walls-and-ceilings-section-i/

Haun, L., Laurence, V., Snyder, T. (2002). Habitat for Humanity, how to Build a House. Tauton Press.

Kubba, S. (2009). LEED Practices, Certification, and Accreditation Handbook. Melbourne, Butterworth-Heinemann.

National Gypsum. Natinal Gypsum Announces Dismissal Attempted Class Action Lawsuit. Retrieved on Nov 12, 2013 from: http://www.nationalgypsum.com/NEWS/releases/04.11.11.htm

Partridge, A. 2012. A Brief History of Wall Construction Materials. Retrieved on Nov 12, 2013 from: http://www.richardshomerepair.com/blog/drywall-articles/111-a-brief-history-of-wall-construction-materials

Spence, W. P. (2008). Installing and Finishing Drywall. New York, NY: Sterling Publishing Company, Inc.

Gypsum Board As A Building Material

Introduction

Gypsum also known as drywall is a building material that is commonly used for interior walls lining. The gypsum board is also known by other names like wallboard, plasterboard, or Sheetrock. Its features like the paper facers and noncombustible core makes it different from other types of building materials used in interior walls lining like hardboard, plywood, and fiberboard. It is made by placing a gypsum composed plaster between two paper layers. The gypsum is mainly a monoclinic mineral that is extracted from sedimentary rocks. In order to foster mixing of the plaster at times fly ash is used to make the mixture. This is mainly a by-product extracted when burning coal and it’s used as an additive for various types of products. Once the mixture of gypsum is put between two pieces of paper the board is heated with a flame to make a strong board. This results in a drywall that can be cut into different size to be used for building construction. Gypsum has been in use for a long period as standard material for ceiling and wall finishing. They are also considered for exterior use because of its feature as a fire resistant material. It’s used in buildings to control sound flow through floors, walls, and ceilings. Innovation in gypsum manufacture has also helped to meet green building requirements as the demand for environmental friendly construction continues to rise. Gypsum is one of the major inventions in the construction technologies. This paper reviews use of gypsum as a building material.

Brief History

In construction of structural walls there has been a remarkable improvement in building technologies. In the ancient Egypt building materials like plaster and stucco were commonly used. In North America, up to 1950s, materials commonly used for interior linings were mainly plaster and lath. However, drywall became popular in the 50 as the best for interior construction. Unlike plaster it offered several advantages like it ease of installation and the fact that unlike plaster it does not crack (Partridge, 2012).

According to Haun, Laurence, & Snyder (2002) there is a possibility that drywall was used for interior construction before Second World War, but it was not very popular. Its popularity in United States as a building material for interior walls can thus be traced back to 1950s. During this period it became the preferred building material for residential houses. Its entry into the market pushed out other materials used for wall construction like plaster and lath. Plaster lost to drywall because it took a longer period covering the wall with it usually 2 to 3 weeks. Beside, after the entire process the house frame were usually left waterlogged. In addition, during the cold winter it took the house a month or more to completely dry. More so, cabinets that were installed after plastering tended to develop sticky drawers. Passage doors on the other hand, were difficult to open, and there was also expansion and buckling of hardwood floors. As a result, the construction industry decided to switch to the drywall technology instead as the preferred building material (Haun, Laurence, & Snyder, 2002).

How it is made/manufactured

Gypsum core is made up of mineral called gypsum extracted from sedimentary rocks. Gypsum is a mineral comprising of calcium sulfate that exists in crystalline form. The molecular formula for the mineral is CaSO4.2H20. This means that a 100 pounds of the gypsum rock consists about 21 pounds of chemically combined water. Manufacturers mine the gypsum rock and transport it to their facility for manufacturing. There the rock is crushed and grounded to the fineness of flour. This flour is them roasted or calcined at a temperature of 350 degree to preferentially discharge some of the water in the form of steam. The roasted gypsum also known as hemihydrates is again mixed with water and placed between two special types of paper to create the gypsum wallboard panel (Spence, 2008). The mixture of calcined gypsum with water is slurry, which is poured in a continuous layer of paper held by a board machine. As the conveyor machine moves the board downwards, calcium sulfate rehydrates or recrystallizes, it combines with water in a chemical process reforming itself into the original rock state. The paper used is both chemically and mechanically enjoined o the core. Once this process is done the board is cut into different lengths and passed through a dryer to remove any moisture that exists (Gypsum Association, n.d). Notably, a smooth white paper is fitted on the good side of the panel to make it easier to absorb paint. The other side comprises of rough, dark colored, porous paper surface. The panels are packed in pairs.

Manufactures can also use synthetic gypsum or flue gas desulphurization to produce the gypsum board. This is made in electricity plants that have a system in place capable of separating sulfur dioxide among the flue gases. This type of a system comprises of scrubbers fitted with calcium carbonate or limestone to chemical combine or absorbs sulfur dioxide before it is discharged to create gypsum or calcium sulfate. The synthetically made gypsum from the electricity plants is transported to the facilities of the gypsum wallboard manufacturers. The process of making the synthetic gypsum is similar to that of mined gypsum with the only difference being that in this case there is no need for crushing.

It is made in different sizes. The standard size of the panel is a 48 inches panel. The most common sizes used in houses construction are 8 and 12 ft. The common thickness for many gypsum wallboard panels is ½ inch. These are the common sizes for the ceiling because they do not sag.

Different types/uses of gypsum board

Gypsum board technologies continue to evolve enabling manufacturers to produces different product varieties used for various purposes. These includes applications as interior walls, bases for ceramic, ceilings, exterior sheathing and soffits, plastic and metal tiles area separation firewalls, shaft enclosures and as fire proof layers for structural elements. Gypsum boards are available in different thickness for various applications. A ¼ inch board is used in exterior walls to improve sound control and in ceilings for curved surfaces and remodeling. A 5/16 inch board is used in sound control and production of manufactured houses. A 3/8 inch gypsum board is used for remodeling and repair as double-layer system. A ½ inch board is uses as a single layer ceiling material for residential construction and as double-layer system in improving fire and sound ratings. A 5/8 inch board is used both as a double and single layer wall system. Its greater thickness improves fire resistance, makes for better resistance, and higher rigidity. Lastly, there is ¾ and 1 inch board used for shaft walls, interior partitions, chaseways, stairwells, corridor ceilings, and separation firewalls (Gypsum Association, n.d).

Besides thicknesses gypsum boards are also categorized into different types. Regular types are popular for ceilings and interior walls finishing. It is capable of controlling sound and fire protection. Regular gypsum wallboard have different thicknesses with ¼ to 3/8 inch boards being used for remodeling works, curved walls, and double layer installations. There is also ½ to 5/8 inch regular board used for ceilings and interior walls. A second type is the fire-resistant gypsum wallboard. It is known as Type-X panel. The paper covering it from edges and back comprises of additives that enables it to prevent fire. It is used to prevent spread of heat to structural embers. Its core comprises of moisture, which evaporates if the panel is heated. This delay the heat passage until all moisture is lost. It also comprises of non combustible fibers that can continue to hold the fire even when all moisture is lost. Installing several layers of this board can delay the time taken for fire to spread. It’s usually used in construction of walls separating a house from a garage or just in usual apartment walls (Spence, 2008).

A third type is moisture-resistant gypsum. The gypsum core is specifically manufactured to act as the base for ceramic tile installation as well as other nonabsorbent finish material in walls. Its core is specifically made to endure impacts of humidity and moisture. There is also a fourth type known as water-resistant gypsum wallboard. Its core is water resistant. Other types includes ceiling wallboard that has a core capable of preventing sagging, flexible gypsum drywall designed for use in curved surfaces, vinyl-surfaced gypsum that comes with different patterns and colors to avoid further finishing work and finally there is high-impact gypsum board used where the wall is likely to be exposed to infrequent penetration or impact (Spence, 2008).

Estimating

It is important to know the amount of materials needed before installing the gypsum wallboard. This will help to minimize time required to run back to the suppliers of materials. It also tells a constructor the time need for a specific job completion. It is also important in order to estimate the total cost of the project. There are certain basic steps that must be followed to estimate the cost. First the constructors should be able to tell the number of wallboard that must be used for the job. This is determined by the panel pattern selected and the size to be placed on each wall. Then estimate the number of nails to be used, which is calculated per panel. Then consider the number of screws to be used. Then determine the size of tape to be used. 100 square feet of gypsum wallboard can use 380 lineal feet of tape. The cost is also affected by the number f corner beads to be used. Each corner uses one bead. Then consider the joint compound. Different manufacturers’ compound can influence amount needed for a specific job. Lastly, the cost of adhesive also influences the cost of the project (Spence, 2008). The labor cost for installation of gypsum board is estimated using square foot.

Chinese drywall

This term is used to indicate environmental health impacts associated with defective drywall that are made in China and shipped to United States. The term gained popularity in 2009. People using these drywalls for their home construction started to report problems like electronic equipment destruction, and health problems like allergies. In contrast, the United States manufactured drywall is reported to meet environmental standards of providing healthy air at homes, hospitals, schools, and in other buildings (National Gypsum, 2011). The Chinese drywall is associated with emission of sulfides that causes the negative health impacts. United States manufactured drywalls have similar compounds like the Chinese drywalls. However, in comparing drywall made in U.S to that of China, laboratory test indicate that the latter has significant proportion of pyrite. It is this pyrite that is attributed with production of sulfur compound due to oxidation. Hydrogen sulfide is attributed to corrosion of copper materials in the homes (Franck & Franck, 2012).

Sustainability

Use of synthetic gypsum is a good way to protect the environment. The impact of gypsum on environment includes disruption of habitat due to mining, emissions during processing and shipment as well as energy use and solid waste generation due to disposal. The use of synthetic gypsum can reduce some of these negative environmental impacts. Because of advancement in technologies manufacturers can now produce more environmental friendly boards. One such product is the EcoRock drywall. It is made from 80 percent of material recycled from industry by products, uses waste materials from cement and steel plant. And can easily be disposed in landfills. It is dried and cured naturally, therefore, uses less energy than in traditional method of processing (Kubba).

References

Franck, H. & Franck, D. (2012). Forensic Engineering Fundamentals. Florida, FL: CRC Press.

Gypsum Association. (n.d). Using Gypsum Board for Walls and Ceiling Section 1. Retrieved on Nov 12, 2013 from: http://www.gypsum.org/using-gypsum-board-for-walls-and-ceilings/using-gypsum-board-for-walls-and-ceilings-section-i/

Haun, L., Laurence, V., Snyder, T. (2002). Habitat for Humanity, how to Build a House. Tauton Press.

Kubba, S. (2009). LEED Practices, Certification, and Accreditation Handbook. Melbourne, Butterworth-Heinemann.

National Gypsum. Natinal Gypsum Announces Dismissal Attempted Class Action Lawsuit. Retrieved on Nov 12, 2013 from: http://www.nationalgypsum.com/NEWS/releases/04.11.11.htm

Partridge, A. 2012. A Brief History of Wall Construction Materials. Retrieved on Nov 12, 2013 from: http://www.richardshomerepair.com/blog/drywall-articles/111-a-brief-history-of-wall-construction-materials

Spence, W. P. (2008). Installing and Finishing Drywall. New York, NY: Sterling Publishing Company, Inc.