The stone, glass, clay and concrete products industry generates a broad array of products, primarily through the modification of mined materials. The industry includes establishments engaged in the manufacturing of flat glass and other glass products, cement, structural clay products, pottery, concrete and gypsum products, cut stone, abrasive and asbestos products, as well as other products.

This industry report uses industry definitions and concepts that underlie the U.S. government's Standard Industrial Classification (SIC) system. In the SIC system, stone, glass, clay and concrete products (SIC 32) is a major industry, one of twenty such industries that form the manufacturing sector. According to the Standard Industrial Classification, there are nine separate stone, glass, clay and concrete products subsectors and 26 market segments defined by broad product categories. Each of the 16,500 stone, glass, clay and concrete products establishments operating in the United States in 1997 was placed in one of these nine industry subsectors:

• Flat glass (SIC 321), including laminated glass;

• Glass and glassware (SIC 322), pressed, blown, or shaped from glass produced in the same establishment;

• Glass products, made of purchased glass (SIC 323), including optical lenses;

• Cement, hydraulic (SIC 324), including portland, natural, masonry and pozzolana cements;

• Structural clay products (SIC 325), including brick, structural clay tile, ceramic wall and floor tile, clay refractories, and other structural clay products;

• Pottery and related products (SIC 326), including vitreous china plumbing fixtures, earthenware fittings, bathroom accessories, vitreous china table and kitchen articles, fine earthenware (whiteware), porcelain electrical supplies, and other pottery products;

• Concrete, gypsum, and plaster products (SIC 327), including concrete block and brick, other concrete products, ready-mixed cement, lime, and gypsum products;

• Cut stone and stone products (SIC 328), including those cutting, shaping and finishing granite, marble, limestone, slate and other stone for building and miscellaneous uses; and

• Abrasive, asbestos and miscellaneous nonmetallic mineral products (SIC 329), including minerals and earths, ground or otherwise treated, mineral wool, nonclay refractories.

Glass. The glass industry consists of a wide variety of manufacturing establishments, including firms engaged in primary glass manufacturing and others which create products from purchased glass. Container glass, flat glass and fiberglass manufacturers are among the most economically significant firms in the primary glass industry.

The glass container sector produces over 40 billion glass containers annually for the food and beverage industry. Other markets for glass containers include: liquor and wine; medicine and health; toiletries and cosmetics; and chemical, household and industrial products.

The flat glass sector produces four main products: tempered glass, laminated glass, glass mirrors, and insulating units. About 35 percent of flat glass shipments are from firms that produce product from melting raw materials (primary producers); the rest (65 percent) are from secondary producers, who produce flat glass from purchased glass.

The fiberglass sector produces two main products: textile fiberglass (electrical glass), and insulation fiberglass. Textile fiberglass is used in the production of fireproof cloth while insulation fiberglass is used in thermal and acoutical insulation.

Other glass sectors included in the stone, glass, clay & concrete products industry are pressed, blown or shaped glass (e.g., bowls, goblets, lenses, jars, tableware and other household glass items) and products made of purchased glass (e.g., furniture, mirrors, windows, table tops, and laboratory glassware).

Cement. Manufacturers in this subsector produce several types of cement, with the most common being portland cement, white cement, and masonry cement. About 97 percent of cement used in the manufacture of concrete is portland cement.

Clay. Although the mining of clay used to make structural clay products is classified elsewhere (under mining, i.e., SIC 145), establishments utilize different types of clay and other additives to manufacture brick, structural clay tile, ceramic wall and floor tile, clay firebrick and other heat-resisting products, and clay sewer pipe.

Concrete. Concrete refers to a product formed from two principal components: aggregate and paste. Aggregate—which can be either natural or man-made—consists of various grades of sand, gravel, crushed stone, or slag. The paste is composed of cement, water and sometimes entrained air. The cement past makes up approximately 25 to 40 percent by volume of concrete. The successful use of concrete in structures has come about from the addition of steel reinforcements. Reinforced concrete is now one of the most common materials from which structures (such as buildings and bridges) are built.

Firms under this subsector produce both ready-mixed concrete—which is unhardened concrete material, and fashion a multitude of concrete products (e.g., brick, architectural blocks, chimneys, columns, paving materials, foundations, curbing, and storage tanks). Another subcategory is lime manufacturing. Major uses of lime are metallurgical, environmental, and construction.

Stone. Stone is applied to rock that is cut, shaped, broken, crushed, or otherwise physically modified for commercial use. The cutting of stones at the quarry is classified as mining. The primary type of stone covered in this subsector is dimension stone. Dimension stone refers to blocks of rock—granite, marble, limestone, slate, sandstone, and other—that are cut and milled to specified sizes, shapes, and surface finishes.

In 1998, the Washington stone, glass, clay and concrete products industry employed 9,400 workers; representing two-and-a-half percent of the state’s manufacturing workforce. Growth in the number of stone, glass, clay and concrete products industry establishments in Washington has been steady; between 1981 and 1998, the average annual growth in establishments has been 2.2 percent, with glassware, pottery, and cement capturing the lion’s share of the industry’s growth.

Figure 1

Number of Establishments in Washington Stone, Glass, Clay & Concrete Products, 1981-1998
Source: Washington Employment Security Department

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Similar to the national industry, concrete and cement dominate the stone, glass, clay and concrete products industry; nearly sixty percent of the total employment in Washington’s stone, glass, clay and concrete products is in concrete and cement. The glass subsectors have been the stellar performers since 1981, adding jobs at an annual rate of 7.8 percent.

Figure 2

Employment in Washington Stone, Glass, Clay & Concrete Products Industry, 1981-1998
Source: Washington Employment Security Department

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Employment change within the stone, glass, clay and concrete products industry parallels that of construction and total nonfarm employment in Washington. Historically, both construction and stone, glass, clay & concrete industries are cyclical performers within the statewide economy.

Figure 3

Annual Employment Change in Washington Construction; Stone, Glass, Clay & Concrete; and Total Nonfarm, 1982-1998
Source: Washington Employment Security Department

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Stone, glass, clay and concrete products in Washington is largely composed of small companies that manufacture various building material products. With the exception of flat glass (SIC 281), stone, glass, clay & concrete products establishments average about 26 employees per establishment. By contrast, flat glass averages over 105 employees per establishment. Over 62 percent of all stone, glass, clay & concrete products workers are found in establishments with 100 or more employees.

Figure 4

Size of Establishments of Washington Stone, Glass, Clay & Concrete Products Industry, 1998
Source: Washington Employment Security Department

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Note: Due to nondisclosure, information on employees for size category 500+ employees are shown in the size category of 250-499 employees.

Average covered wages for stone, glass, clay & concrete products workers was $34,809 in 1998, 3 percent above the statewide nonfarm average of $33,922, yet 18 percent below the manufacturing average of $42,247. Between 1981 and 1998, real (i.e., without inflation) wages declined by 4.6 percent in stone, glass, clay & concrete products, while real wages and salaries in statewide manufacturing and nonfarm increased by 10.2 percent and 17.9 percent, respectively.

The distribution of hourly wages for stone, glass, clay & concrete products is dissimilar to the state, with a pronounced disposition toward mid-level hourly wages. Nearly three-quarters of all workers in the stone, glass, clay & concrete products industry earn between $8 and $20 per hour, compared with 54 percent of all nonfarm workers in the state.

Table 1

Real Average Wages for Washington Covered Stone, Glass, Clay & Concrete Products Workers, 1981-1998 (1998 dollars)
Sources: Washington Employment Security Department,
U.S. Bureau of Economic Analysis

Figure 5

Hourly Wages for Washington Stone, Glass, Clay & Concrete Products Workers, 1997
Source: Washington Employment Security Department

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The labor force in the stone, glass, clay & concrete products sector is dominated by operatives and laborers. Common stone, glass, clay & concrete products occupations within this group are machinists, truck drivers, and equipment operators. Clerical and managerial occupations are also important in stone, glass, clay & concrete products.

Table 2

Occupational Profile of Stone, Glass, Clay & Concrete Products Workers in Washington, 1998 and 2008
Source: Washington Employment Security Department

In terms of gross state product, stone, glass, clay & concrete products sector’s share has remained relatively stable during the 1990s. The sector’s index of specialization has not yet reached 1.0; implying that stone, glass, clay & concrete products in Washington contributes less to the state economy compared to its national counterpart.

Most stone, glass, clay & concrete products manufacturers in Washington service local and regional markets. Only a modest amount of the state’s industry is exported to foreign customers. In 1998, stone, glass, clay & concrete products foreign exports from Washington totaled $52.5 million, less than 0.2 percent of the state’s total exports.

Figure 6

Index of Specialization for Washington Stone, Glass, Clay & Concrete Products Industry, 1977-1997
Source: U.S. Bureau of Economic Analysis, Gross State Product series.

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Outlook

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Prepared by Chase Economics, Tacoma
For Washington Employment Security Department,
Labor Market & Economic Analysis Branch, Olympia, 1999.
Published in agency’s Internet homepage, Industry series (www.wa.gov/esd/lmea)