Finish Materials

Finish materials may be an integral part of the architectural assemblies that define an interior space, or they may be added as an additional layer or coating to the constructed walls, ceiling, and floor of a room. In either case, they should be selected with the architectural context in mind. Together with furnishings, finish materials play a significant role in creating the desired atmosphere in an interior space.

The search for new finish materials can begin in trade and general design magazines. The Internet is next, starting with design blogs easily bookmarked for future reference. A Pinterest account provides the option to establish boards to organize “Pins” for inspiration—and to keep track of furniture, furnishings, and equipment (FF&E) as well as finishes you want to remember—is also a help. Design trade shows and fairs—including those beyond your immediate location—are another great source of inspiration. If you cannot attend in person, follow up with press accounts. Follow trends in related fields, such as fashion and industrial design, and the world at large.

Faux finishes imitate natural materials. Manufacturers are introducing faux finishes that perform better than the real thing, such as onyx-like surfacing that is scratch, stain, and heat resistant.

Today, handcrafted finish materials are providing options for designers who want products that say something about clients as individuals. Many craftspeople rely on social media to publicize their products.

Functional Criteria

Hydrophobic properties have begun to take their place among the functional criteria for interior finish materials. What is called the Lotus Effect derives from the property of lotus plant leaves that are coated with tiny wax crystals, causing water to bead up and roll off, leaving no moisture behind. Scientists have applied nanotechnology to the lotus effect to produce a variety of products, including self-cleaning paint that washes itself clean with rain; countertops, tiles, and appliances that repel liquids; floors that resist dirt, oil, and foods without wax or silicone sealants; fabrics that will not allow penetration by dirt, water, and oils; wall coverings that resist moisture, fire, and chemicals; and carpets that help clean air of household odors.

The phenomenon that keeps a shark's skin free of barnacles or algae is being used to develop germ-resistant surfaces with little water resistance, properties of great value in kitchen and healthcare design.

Other functional criteria include:

• Safety, health, and comfort
• Durability in anticipated use
• Ease of cleaning, maintenance, and repair
• Required degree of fire resistance
• Appropriate acoustic properties

Aesthetic Criteria

• Color, natural or applied
• Texture
• Pattern

Economic Criteria

• Initial cost of acquisition and installation
• Life-cycle assessment (LCA) of materials and products, including environmental and health impacts, from acquisition of raw materials through end-of-use recovery

Recycling of timber

Sustainable Design Criteria

• Minimization of new materials and reuse of existing materials
• Use of materials with recycled content
• Use of rapidly renewable and certified sustainable materials from local sources
• Use of products from manufacturers who use sustainable processes
• Minimization of waste in construction, installation, and packaging
• Durability and flexibility of use
• Reduction of embodied energy used in processing and shipment
• Avoidance of toxic materials

Finish flooring is the final layer of the floor assembly. Because flooring is subject to direct wear and represents a major portion of a room's surface area, it should be selected with both functional and aesthetic criteria in mind.

• Durability: Resistance to physical abrasion, denting, and scuffing.
• Ease of maintenance: Resistance to dirt, moisture, grease, and staining, especially in work and high-traffic areas.
• Foot comfort: This quality is related to the degree of resilience and—to a lesser degree—warmth.
• Slip resistance: Avoid hard, slick flooring materials, especially in areas susceptible to wetting.
• Impact noise: Resilient flooring can cushion some impact noise. Soft or porous flooring materials reduce impact noise and airborne sound.

The dirt that normally collects on a floor can be disguised by a mixture of neutral colors of middle value, a pattern that camouflages any dirt and surface marks, or a material whose natural color and texture is more noticeable than any dirt on the floor.

The warmth of a floor may be real or apparent. A flooring material may be warmed by radiant heat and kept warm by its own thermal mass or by insulating the floor. The flooring may appear warm if it has a soft texture, a middle-to-dark value, or a warm hue. Of course, in warm climates, a cool floor surface would be more comfortable than a warm one.

Electrostatic discharge (ESD) is the phenomenon that produces a mild jolt of electricity from static electricity when you touch a metal doorknob after walking across a carpeted floor. Today, the rapid proliferation of electronic devices has led to higher sensitivity to ESD control in any company that desires to successfully manufacture and deliver undamaged electronic parts. The need for dissipative flooring solutions has taken on added significance. Common materials that may carry an electrostatic charge include waxed, painted, or plastic work surfaces; waxed, common vinyl tiles, or sealed concrete floors; clothing; vinyl, fiberglass, or finished wood chairs; common plastic bags, foam, trays or tote boxes; and assembly equipment. Once established, a material becomes electrostatically charged if it is not grounded or dissipated naturally over time. It can then be transferred from the material to create an ESD event. ESD has the potential to disrupt the normal operation of an electronic system and cause degradation, destruction, failure, or malfunction of equipment.

ESD assessments should be conducted under the advisement of a qualified and certified professional. Many flooring products are designed to be used in conjunction with other wearable antistatic products. Various types of ESD flooring can minimize static charge generation and drain static electricity from occupants of spaces at risk for an ESD event. They are available as vinyl tiles/sheets, vinyl composition tile, rubber, or carpet flooring products.

The floor can play an active role in determining the character of a space through its color, pattern, and texture.

A light-colored floor will enhance the light level within a room, while a dark floor will absorb much of the light falling on its surface. A light color suggests spaciousness and emphasizes the smoothness of polished floors. A dark color gives a floor plane depth and weight.

Unlike the wall and ceiling surfaces of a room, a floor transmits its tactile qualities—its texture and density—directly to us as we walk across its surface. The physical texture of a flooring material and the way it is laid are directly related to the visual pattern created.

A neutral, patternless floor can serve as a simple background for a room's occupants and furnishings, but through the use of pattern, a floor can also become a dominant element in an interior space. The pattern can be used to define areas, suggest paths of movement, or provide textural interest.

Our perception of a flooring pattern is affected by the laws of perspective. Thus a small-scale pattern may be seen as a fine texture or a blended tone, rather than as a composition of individual design elements. In addition, any continuous linear elements in a flooring pattern will dominate. Directional patterns can affect the apparent proportion of a floor, either exaggerating or foreshortening one of its dimensions.

Finish flooring is usually separated into hard flooring such as wood, stone, and tile; resilient flooring such as linoleum or cork; and soft floor coverings, which consist primarily of carpets and rugs.

Of the hard floor finishes, wood flooring is admired for its warm, natural appearance and its attractive blend of comfort, resilience, and durability. It is also fairly easy to maintain under moderate use and, if damaged, can be refinished or replaced.

Durable, close-grained species of hardwoods (white and red oak, maple, birch, beech, and pecan) and soft woods (Southern pine, Douglas fir, Western larch, hemlock, and others) are used for wood flooring. Of these, oak, Southern pine, and Douglas fir are the most common. The best grades are clear or select, which minimize or exclude defects such as knots, streaks, checks, and torn grain.

Woods used for flooring should be from certified sustainable sources. Rare or exotic species should be avoided. Antique or reclaimed wood flooring, retrieved from buildings that are about to be demolished, offers a distinctive character and patina.

Other types of wood used for flooring include bamboo and antique or reclaimed wood flooring. Bamboo is technically a grass, and its ability to regrow quickly after harvesting has earned it a reputation as a sustainable material. Bamboo flooring was originally laminated with a urea-formaldehyde adhesive. Today, much less toxic glues provide the same strength and finish, making bamboo floors available in virtually the same styles and finishes as hardwoods. Bamboo floors are available in three types of grains: strand-woven grain, vertical or edge grain, and horizontal or flat grain.

Solid wood flooring is available in strips and planks. Board flooring is usually sold in the form of narrow strips, although planks up to 6 inches (152-mm) wide are also available.

Engineered hardwood flooring is impregnated with acrylic or sealed with urethane or vinyl. Laminated flooring assembles high-pressure laminates, including wood veneers, into durable, acrylic-urethane sealed panels. Bamboo is also laminated under high pressure, milled into planks, immersed in polyurethane, and coated with acrylic polyurethane. Most bamboo products must travel long distances to reach the U.S. market.

Wood flooring is most often finished with clear polyurethane, varnish, or a penetrating sealer. Finishes can range from high gloss to satin. Ideally, the finish should enhance the durability of the wood and its resistance to water, dirt, and staining, without concealing the wood's natural beauty. Stains are used to add color to the natural color of the wood without obscuring the wood grain. Wood flooring can also be waxed, painted, or stenciled, but painted surfaces require more maintenance.

Tile and stone flooring materials are solid and durable. Depending on the shape of the individual pieces and the pattern in which they are laid, these flooring materials can have a cool, formal appearance or give a room an informal feeling.

Ceramic mosaic tiles—small, modular units of natural clay or porcelain—are widely used for flooring. The natural clay type is unglazed, with muted earth colors; the porcelains can have bright colors and are vitreous (glasslike, dense, and impervious).

Quarry tiles and pavers are larger modular flooring materials. Quarry tiles are unglazed units of heat-hardened clay. Larger-sized ceramic tiles are available in a range of patterns, some of which mimic natural stone or wood, and are practically impervious to moisture, dirt, and stains.

Stone tile flooring materials provide a solid, permanent, and highly durable floor surface. Types of stone commonly used for flooring include:

• Slate: Reddish browns, grays, greens, blues, and blacks. Available in square or irregular shapes, can be formal or informal.
• Marble: White, pinks, greens, browns. Shaded and striped. Lends itself to high polish and formal elegance.
• Granite: Over 200 colors. Polishes well, also honed or thermal finishes.

Tile installations are either thinset or thickset. Thinset installation uses adhesive to attach the tile. Thickset installation is used over floors subject to bending and deflection. The tile is set on a layer of mortar that helps prevent cracking.

Tile or stone flooring is set in grout. Grout is available in a variety of colors and can be selected to blend or contrast with the flooring material.

Current trends in tile include wood, steel, stone, and concrete-effect tiles; geometric forms including hexagons; references to contemporary art; mirrored and metallic surfaces; and raised surfaces that mimic motion. Glazed porcelain tiles are available in solid blocks of color or abstracted graphic designs.

Concrete can be used as a finish floor surface if smooth and level enough. It should be sealed against stains and grease. Concrete can be painted, stained, or integrally colored when cast. An exposed aggregate finish can provide textural interest.

Terrazzo is a special type of exposed aggregate finish with mosaic-like patterns created by marble chips. It is available in poured or precast forms. Standard terrazzo has a ground and polished finish consisting mainly of relatively small stone chips, with resin or cement-based binders. Designer or exotic terrazzo use specialty aggregates with epoxy resin binders. Venetian terrazzo has large stone chips, with smaller chips filling spaces. Palladiana terrazzo consists of cut or fractured marble slabs set by hand into a pattern, with smaller chips set into the spaces between. Rustic terrazzo has a uniformly textured finish that exposes rough chips and is primarily for exterior use.

Seamless, durable fluid-applied flooring materials are used for commercial, industrial, and institutional installations. The flooring materials are poured over concrete or other rigid substrates. Seamless quartz flooring consists of colored quartz aggregates in clear or colored epoxy.

Types of Terrazzo

Standard terrazzo is a ground and polished finish that consists mainly of relatively small stone chips.

Venetian terrazzo consists mainly of large stone chips, with smaller chips filling the spaces between.

Thinset Terrazzo
¼″ to ½″ (6 to 13 mm) epoxy terrazzo topping is placed over a wood, metal, or concrete subfloor

Monolithic Terrazzo
½″ (13 mm) thick cement matrix terrazzo topping is laid over a rough-finished concrete slab.

Bonded Terrazzo
½″ (13 mm) thick cement matrix terrazzo topping and a sandcement underbed are mechanically bonded to a rough-finished concrete slab.

Sand-Cushion Terrazzo
½″ (13 mm), ⅝″ (16 mm), or thicker cement matrix terrazzo topping is installed over a reinforced mortar underbed and an isolation membrane of sand to control cracking when structural movement is expected.

Resilient flooring materials provide an economical, dense, nonabsorbent flooring surface with relatively good durability and ease of maintenance. Their degree of resilience enables them to resist permanent indentation while contributing to their quietness and comfort underfoot. The degree of comfort provided will depend not only on the material's resilience but also on the type of backing used and the hardness of the supporting substrate.

Linoleum and vinyl sheets come in rolls from 6 to 15 feet (1829- to 4572-mm) wide, as well as in square tiles and planks. They can be cut into patterns in the factory or the field. Resilient flooring materials are available as tiles, typically 12 inches (304-mm) square. While sheet goods provide a seamless floor, tiles are easier to install if the floor outline is irregular. Individual resilient tiles can be replaced if damaged.

Resilient flooring types vary in their performance and sustainability.

• Rubber tile (available in square tiles and planks), vinyl sheet, linoleum, and cork products offer the best resilience.
• Vinyl and linoleum sheets and tiles resist staining, grease, and cigarette burns well.
• Vinyl products, especially sheet materials, are not sustainable materials.
• Natural linoleum and cork are made of renewable materials and have lower VOC levels.
• The pattern on vinyl tiles and sheets can wear off, whereas linoleum and cork have consistent color throughout.
• Leather tiles, which are comparatively expensive, develop an attractive patina with time and use.

The wood or concrete substrate for resilient flooring should be clean, dry, flat, and smooth to prevent any irregularities in the base material from showing through. Resilient flooring materials are not designed to be laid over ceramic tile. Linoleum and cork tiles should not be laid below grade. Some resilient flooring materials come with their own adhesive for ease of application.

There are two major categories of soft floor coverings—carpeting and rugs. These coverings provide floors with both visual and textural softness, resilience, and warmth in a wide range of colors and patterns. These qualities enable carpeting to absorb sound, reduce impact noise, and provide a comfortable and safe surface to walk on. As a group, carpeting is easier to install than hard floor coverings, and is fairly easy to maintain in a relatively clean environment.

Nearly all of the many kinds of carpet are recyclable. Some face fibers can be broken down and used to make new product. Many companies that recycle carpet will also take carpet padding, which is recycled separately from carpet. Recycled carpet is usually turned back into plastic resin, which can be used to create other products, sometimes including new carpet. Carpeting is most often manufactured in 12-foot (3658-mm) wide rolls, referred to as broadloom. Some specialty carpet comes in widths up to 18 feet (5486-mm) wide. Woven carpet is also manufactured in 27- to 36-inch (6858- to 9144-mm) widths referred to as narrow goods or runners and typically used in residential installations.

Broadloom carpet is sold by the square foot, cut to fit, and installed over cushion using tackless strips, or glued down using an adhesive. Carpeting normally is installed wall-to-wall, covering the entire floor of a room.

Because carpet is usually fastened to a floor, it must be cleaned in place and cannot be turned to equalize wear. The location of seams, the type of backing, and the technique used to seam carpet can have a substantial effect on the useful lifespan of a broadloom carpet.

Carpet tiles are modular pieces of carpet that can be laid to resemble a seamless wall-to-wall installation or can be arranged in subtle or bold patterns. They are designed to be used in both residential and commercial settings. They are usually constructed by tufting, although some are made by fusion bonding. Carpet tiles offer the following advantages over broadloom carpet:

• They can be easily cut to fit odd-shaped contours with a minimum of waste.
• Individual tiles can be replaced if worn or damaged.
• They can be moved easily and reused.
• In commercial installations, the tiles can be removed for access to underfloor utilities.

Carpet tiles are available in a range of square sizes, as well as a growing variety of planks and other shapes. Tiles are designed to be free-laid on a subfloor with only the perimeter tacked in place with adhesive, fully glued down, or tacked in place with pressure-sensitive adhesive dots. Commercial-grade carpet tiles have a backing strong enough to prevent shrinkage or expansion of the tile and to protect the carpet edges from unraveling.

The performance of a carpet depends upon several factors, most importantly the type of fibers used. Each carpet manufacturer offers blends of the generic face fibers that improve on specific characteristics such as durability, soil resistance, cleaning ability, color, and luster.

Carpet Fiber Types

Nylon has excellent strength and wearing ability, is soil-, mold-, and mildew-resistant, and dries quickly. Solution-dyed nylon resists fading from sunlight and chemicals. Newer branded soft nylons with smaller-diameter fibers have increased nylon's desirability for residential use.

PET polyester is a durable form of polyester made from recycled plastic containers. It resists soiling, abrasion, stains, and fading.

Olefin (polypropylene) is colorfast and resistant to abrasion, soil, and mildew. Most olefin lacks nylon's resiliency and crush resistance, and is often used for indoor/outdoor carpets. A new type of olefin fiber is specially processed for softness, stain resistance, and durability.

Wool has excellent resilience and warmth, and good soil, flame, and solvent resistance. Wool is a sustainable material with an outstanding ability to absorb color. It cleans and maintains well, has superior long-term appearance retention, and ages gracefully.

Dye Techniques

Solution dyeing consists of adding dye to synthetic carpet fiber material before the yarn is extruded. This technique is the most colorfast and resistant to chemicals, gasses, bleaches, and sunlight.

Continuous dyeing involves applying dye to the open face of a carpet and setting it by steam injection. This is the least expensive dyeing method, but it is less colorfast and uniform.

Piece or beck dyeing consists of running white carpet with primary backing (called greige goods) through a large, shallow dye vat (beck) before the secondary backing is applied.

Print or contact dyeing can be used on almost any type of pile. This technique produces good colorfastness and penetration.

A spinneret is a multipored device through which viscous plastic polymer is extruded into cool air or liquid to cool and form fibers.

Microscopic view of nylon fibers

Microscopic view of wool fibers

Tufted carpet

Woven carpet

Fusion-bonded carpet

Tufted Carpet

Most commercial carpet is made by inserting tufts of yarn into a primary backing. A secondary backing may be added as a cushion and for greater dimensional stability.

Woven Carpet

Made on looms, woven carpet is the product of a much slower and more expensive process than tufting. Axminster carpets, which are generally made of 100 percent wool or 80 percent wool and 20 percent nylon, are the most durable and long-wearing carpet type. They are often used in hospitality and residential applications. Wilton carpet is a decorative wool carpet used in homes. Both of these carpet types are woven through the back of the fabric and do not require a secondary backing.

Fusion-Bonded Carpet

Fusion-bonded carpets are constructed in facing pairs with the pile embedded in the backing on each side, then cut apart to create cut pile. They are used for heavy foot traffic, such as in airport terminals.

Carpet Cushions

Carpet cushions add resilience, lessen impact noises, and can significantly extend the life of a carpet. They are most commonly used with residential carpets. However, some types will compress too easily and are not durable under heavy traffic.

• Foam or sponge rubber pads have a synthetic facing laminated on top, and may break down with use.
• The backing of urethane foam pads breaks down with use, and they are not recommended for heavy traffic.
• Different colors and densities of foam scraps are bonded together and compressed to make rebounded pads, which have a top skin.
• Slab rubber contains less air and provides better resistance to furniture denting and crushing.
• Waffle rubber pans work well with humidity but not with dry air, and may be too soft.
• Jute, hair, synthetic, or recycled textile fibers are dense and used for area rugs and commercial carpet.
• Super-dense urethane frothed foam is extremely durable, and is used for woven carpets and radiantly heated floors.

After color, texture is a carpet's prime visual characteristic. The various carpet textures available are a result of the pile construction, the pile height, and the manner in which the carpet is cut. There are three major groups of carpet textures:

• Cut pile results when every yarn loop is cut. It can be produced in tufted, woven, or bonded constructions.
• Loop or uncut pile is tougher and more easily maintained than cut pile. Loop pile can be produced through tufted, woven, and knitted techniques. It is durable and easy to maintain, and works well with wheeled furniture.
• Cut-and-uncut pile adds a degree of softness to all-loop pile with varying proportions of cut and uncut pile. It can be produced in tufted and woven constructions.

Carpet Pile Terms

• Density is a measure of the amount of pile fiber by weight in a given area of carpet. Increased density generally results in better performance.
• Pitch refers to the number of ends of yarn in a 27-inch (685-mm) width of woven carpet.
• Gauge refers to the needle spacing across the width of a tufting machine, expressed in fractions of an inch.
• Face weight is the total weight of face yarns measured in ounces per square yard.

Velvet or Plush
Smooth, finely sheared cut pile shows traffic marks.

Twist or Friezé
Twists are set into yarn to create a heavier, rougher texture.

Level Loop
Looped tufts of the same height

Saxony
Multi-ply yarn gives smooth, soft appearance, shows footprints.

Shag
Textured surface is created with long, twisted yarns.

Multi-Level or Patterned Loop
Uncut loops create sculptured patterns.

Cut and Loop
Combination of loop pile with cut pile creates patterns.

Indian Numdah

Navajo Rug

Afghanistan Bokhara

Chinese Bengali

Rugs are floor coverings manufactured or cut to standard sizes, often with a finished border. They are not intended to cover the entire floor of a room and are therefore simply laid over another finish flooring material.

Room-sized rugs cover most of a room's floor, leaving a strip of finish flooring exposed along the room's edges. They approximate the appearance of wall-to-wall carpeting but can be moved if desired, removed for cleaning when necessary, and turned for more even distribution of wear.

Area rugs cover a smaller portion of a room's floor and can be used to define an area, unify a furniture grouping, or delineate a path. Decorative rugs, especially handmade ones, can also serve as a dominant design element and provide a focal point for a room's arrangement.

Knotted, hooked, braided, or hand-tufted techniques produce various styles of looped and/or cut yarns that are commonly used for area rugs. Oriental rugs are hand-knotted, and made with individual knots that will not unravel. Today, digital printing allows manufacturers to collaborate with designers on custom designs.

Wall finishes are used to increase a wall's durability, sound absorption, light reflectance, or appearance. Some wall finishes are an integral part of a wall's material structure, some are separate layers attached to the frame of a wall, and still others are thin coatings or coverings that are applied over a wall surface. In addition to aesthetic factors such as color, texture, and pattern, there are functional and economic considerations in selecting a wall material and finish, including the following:

• If it is an applied material, what type of support or base is required?
• What type of finish, coating, or covering will a wall accept?
• How durable must the material or finish be, and how easy is it to maintain?
• What degree of sound absorption, light reflectance, and fire resistance is required?
• Does the wall finish contain toxic materials or off-gas volatile organic compounds (VOCs)?
• Does the wall finish contain recycled or recyclable materials?

Storing finish material samples on open shelving with nearby tables for discussions encourages office occupants to keep the materials organized.

Made in the U.S. from recycled glass, this finish has color, pattern, size, and shape unique to each slab.

Architectural resin panels are available as translucent or clear sheets, with embedded materials and interlayers, and as prepatterned sheets. Some products contain preconsumer recycled resin; panels without embedded materials can be more easily recycled. These panels can be mounted as dividing walls or attached off a wall surface with offset hardware.

Advances in laminate technology today provide vacuum-formed 3D panel products (3DLs) with ever-increasing realism that helps to reshape interiors well beyond the typical two-dimensional surface. These tactile panels have opened up virtually endless design options for commercial interiors. Both attractive and durable, they offer design flexibility and are available in multiple sizes, useable for walls, wainscoting, ceilings, backsplashes, furniture, display fixtures, and other interior design applications. The fresh patterns and textures combine with customization options to deliver both aesthetic appeal and design advantages.

Today's 3D laminate manufacturing provides consistent quality, custom patterns, and color matching at smaller minimums and lower costs than available for laminate panels in the past. A construction specifier can choose from a wide variety of three-dimensional patterns and then combine them with one of many finish options to create a unique panel. Some manufacturers also offer custom sheets with logos or other branding features.

The base of the finished product is a raw thermoplastic material such as polyvinyl chloride (PVC), polyethylene terephthalate glycol (PETG), or acrylonitrile-butadiene-styrene (ABS). Roll-formed decorative foils give the finish a metallic, patina, wood grain, or solid color appearance. Invisible layers of special coatings or protective masking can provide protection. After lamination and sheeting, the substrate is vacuum formed into the finished pattern. This is followed by cooling and cutting, and inspection for quality control. Finished panels are extremely lightweight, and can be rolled for cost-effective shipping. Manufacturers often sell wall panels up to 4 × 8 feet (1219-mm × 2438-mm) in size, wainscot panels between 30 and 32 inches × 48 inches (762- and 813-mm × 1219-mm), and smaller panels for kitchen backsplashes and glue-up from 18 × 24 inches (467-mm × 610-mm) or less.

Solid surfacing materials are often used for countertops, as well as for other residential and commercial finishes. Solid surfacing materials are resistant to water, stain, heat, chemicals, wear, and impact and have high bacterial and fungal resistance. They are available in a variety of thicknesses, including ⅛-inch (3-mm) thick veneer. Solid surfacing materials are usually prefabricated at the installer's shop, and then assembled on-site. Installation seams are glued, leaving little evidence of the joint.

Wood Wall Panels

Wood paneling consists of a series of thin sheets of wood framed together by strips of wood. Vertical strips are called stiles, and horizontal strips are referred to as rails. Wood paneling includes solid lumber paneling, wood veneer paneling, and plastic-laminate faced wood paneling. Ready-to-use stained and finished hardwood panels are available in many different colors and wood species.

Solid wood boards offer durability and create texture. Wall pattern and texture depend on the width, orientation, and spacing of the boards as well as on the joint details. Beadboard consists of tongue-and-groove strips of wood grooved to look like two thin strips; it is used as wainscots on walls and on ceilings.

Composite wood panels use wood fiber left over from other manufacturing processes. They are more structurally stable than solid wood, and may last longer as well. The wood in composite panels acts as a carbon sink that may sequester more carbon than is expended in their production, transportation, and installation. Composite panels produced in North America now meet and usually exceed established indoor air quality goals.

Particleboard and medium density fiberboard (MDF) panels are manufactured by mixing wood particles or fibers with resin, paraffin wax, and other additives. The panel is then consolidated and cured under pressure and heat, then sanded and sawn to the dimensions desired. Composite panels can be engineered for moisture resistance, fire resistance, indoor air quality goals, density, and screw-holding power. They can be designed to be lightweight and produced in different thicknesses and dimensions. Most composite panels have a decorative surface of veneer or high-pressure laminate. Thermally fused laminate (TFL) is a common surface, made of printed or solid-colored decorative paper saturated with melamine resin and fused to the composite panel core under heat and pressure.

Particleboard is made up of small wood particles. The wood chips in MDF are further refined to cellulosic fibers, producing a panel with both a smooth surface and homogeneous core.

Wood Board Base Details Details at ceiling can be treated in a similar manner.

Plywood

Plywood is a wood panel product made by bonding veneers together under heat and pressure, usually with the grain of adjacent plies at right angles to each other. Plywood cores may be made of particleboard, medium-density fiberboard (MDF), veneer core, or lumber core. Some plywood products contain formaldehyde. Panels are typically 4 feet × 8 feet (1219-mm × 2438-mm) and ¼ to ¾ inch (6- to 9-mm) thick.

Wood panel products are typically faced with either decorative laminates/overlays or wood veneers. There are two types of wood veneers, hardwood and softwood; hardwood is used for wall finishes. Veneers are sliced in a variety of ways, including quarter slicing, rift cutting, and rotary cutting. Adjacent thin leaves of sliced wood can then be arranged in patterns such as book, herringbone, slip, diamond, and random matching.

Examples of Plywood Joints
Exposed edges of plywood panels must be finished with a hardwood strip or concealed with trim molding.

Plaster is a composition of gypsum or lime, water, sand, and sometimes another fiber. It is applied in a pasty form to the surfaces of walls or ceilings and allowed to harden and dry. Gypsum plaster is a durable, relatively lightweight, and fire-resistant material that can be used on any wall or ceiling surface that is not subject to moist or wet conditions. Veneer or thin-coat plaster is a ready-mixed gypsum plaster applied as a very thin skim coat finish over a veneer gypsum board base, which is commonly called blueboard.

Plaster is applied in either two or three layers, the number of which depends on the type and strength of base used. Two-coat plaster uses a base coat followed by a finish coat. Three-coat plaster is applied in three successive coats, a scratch coat followed by a brown coat and a finish coat.

• The scratch coat is the first coat in three-coat plaster. It must adhere firmly to the lath and provide a better bond for the second or brown coat.
• The brown coat is a roughly finished, leveling coat of plaster—either the second coat in three-coat plaster or the base coat applied over a gypsum lath or masonry.
• The finish coat of plaster serves as the finished surface or as a base for decoration.
• The total thickness of a plaster finish is from ½ to ¾ of an inch (12- to 19-mm).

The final appearance of a plaster surface depends on both its texture and its finish. It is usually troweled to produce a smooth, nonporous finish. Plaster may have one or more integral colors, or may be painted either a single color or with multiple layers of paints and glazes. Smooth finishes will accept textile or paper wall coverings. Plaster can be molded and cast into sculptural shapes by specialists for renovations of historic projects.

Wood or metal stud frame or furring over masonry or concrete wall

Metal accessories are required to finish and protect the edges and corners of plaster surfaces

Gypsum board—often called drywall or plasterboard—consists of a gypsum core surfaced with paper or other covering material. It may be finished by painting or by the application of ceramic tile or a flexible wall covering.

Common types of gypsum board include the following:

• Regular gypsum board for interior walls and ceilings
• Moisture-resistant gypsum board used as a backing for ceramic tile in high-moisture conditions
• Fire-resistant (Type X) gypsum board used in fire-resistant construction

Gypsum board may be bent, depending on its thickness.

Metal trim shapes are required to finish and protect the edges and corners of gypsum board surfaces.

Ceramic Wall Tile

Ceramic wall tiles are modular surfacing units of fired clay and other ceramic materials. They provide a permanent, durable, waterproof surface for interior walls. They are available in bright or matte glazes in a wide range of colors and surface designs.

Specialty tiles include glass tiles, handmade and custom tiles, special sizes, and trim pieces. Grouts for wall tiles are available in a wide variety of colors. Avoid using highly pigmented grouts with contrasting colored tiles, as they may bleed.

Ceramic tile may be applied with either the thinset or the thickset process.

• In the thinset process, ceramic tile is bonded to a continuous, stable backing of gypsum plaster, gypsum board, or plywood, using a thin coat of dry-set mortar, latex-portland cement mortar, epoxy mortar, or an organic adhesive.
• In the thickset process, ceramic tile is applied over a bed of portland cement mortar. The relatively thick ½- to ¾-inch (13- to 19-mm) bed allows for accurate slopes and true planes in the finished work. Suitable backings include metal lath over concrete, masonry, plywood, gypsum plaster, gypsum board, and stud framing.

Glass tile can be used on walls, floors, and countertops, both interior and exterior. Manufactured glass tiles with flat surfaces and regular dimensions are easier to install than hand-cut, highly textured tiles. Colored manufactured glass tiles are installed with white thinset adhesive with a latex additive and latex-modified grout.

Rib weave wall covering

Photographic wall covering

In addition to being painted, smooth plaster and gypsum board surfaces can be finished with a variety of flexible wall coverings that are available in a wide range of colors, patterns, and designs. There are six wall-covering categories based on performance:

1. Decorative only: Untested wallpaper and other residential wall coverings
2. Decorative with medium serviceability: Tested but primarily for residential use
3. Decorative with high serviceability: Tested for medium residential use
4. Type I commercial serviceability: Tested for heavy consumer and light commercial use, such as private offices and hotel rooms
5. Type II commercial serviceability: Tested for higher standards and appropriate for public areas such as dining rooms, corridors, and classrooms
6. Type III commercial serviceability: Tested for the highest standards and used for high-traffic service corridors

Wallpaper has a paper face and a paper back. It is not commonly used in commercial design, as it is subject to soiling, abrasion, and fading, and is not tested for flame resistance.

Cloth- or paper-backed vinyl wall coverings are designed for serviceability and durability, and are tested for flame resistance as well. They are easily cleaned and resistant to fading and abrasion. However, environmental problems exist in their manufacture, use, and disposal, and alternatives are increasingly used.

Fabrics such as wool, linen, cotton, burlap, and grasscloth require back-coating as a barrier to prevent adhesive from bleeding through to the fabric's face and to improve dimensional stability. They should be treated for soil resistance and some may require flame-retardant treatment, which has sustainability problems.

Cork obtained from the renewable bark of the cork oak tree is both durable and resilient. It accepts either wax or polyurethane finishes and possesses excellent acoustical and thermal ratings, but moisture may cause problems.

Paints

Latex paints are the most commonly used type of interior paints. They are water-based, fast drying, porous, and easy to clean up with water. Alkyd paints are made with solvent-thinned resins that utilize oil-modified polyesters as a vehicle. Use of alkyd paints may be restricted in some parts of the United States for environmental reasons.

From its early days prior to the 1700s, paint was mixed by hand in small batches. The 1800s brought the advent of paint factories producing ready-mixed paints and greatly increasing demand. In the twentieth century, manufacturers replaced natural ingredients with synthetic pigments and stabilizers, producing uniform batches of paint.

Lead is a neurotoxin that is especially damaging to fetuses, infants, and young children, and can cause learning disabilities, nausea, trembling, and numbness in the arms and legs. Lead was banned from most paint in the U.S. in 1978 by federal law. Lead particles from older paint in existing buildings are suspended in the air or settle on surfaces such as carpets, which can release the particles back into the air when disturbed. Children ingest and inhale lead-based paint chips or dust by playing on floors and other dusty surfaces and then putting their hands in their mouths or noses. Lead exposure has been implicated in attention deficit disorder, impaired hearing, reading, and learning disabilities, delayed cognitive development, reduced IQ scores, mental retardation, seizures, convulsions, coma, and death.

Houses built prior to 1950 are likely to contain paint with high levels of lead. Current efforts to remove and/or repair deteriorated lead-based paint, along with other measures to reduce and prevent recurring accumulation of lead in dust, have resulted in substantial and sustained reductions in interior lead dust and children's blood levels.

Antimicrobial paint is a new product useful in passive infection control. It contains a disinfectant quaternary ammonium compound that kills 99.9 percent of five pathogens commonly associated with hospital-acquired infections (HAIs) within two hours of exposure on a painted surface, and remains effective for four years on an intact and properly maintained surface. It is recommended for patient rooms, as well as for childcare centers, assisted-living facilities, cruise ships, and other environments where infections can spread easily.

Paint Sheens

The sheen or gloss of paint depends on the size of the particles of pigment and the ratio of pigment to liquid. Although different manufacturers use a variety of names for the levels of gloss, the basic categories are flat, semigloss, and gloss. Some companies sell eggshell, pearl, and/or satin paints that are more washable than flat paints and less shiny than semigloss.

• Flat paints are used for ceilings, and for walls in rooms with low surface contact. Their low sheen can conceal minor surface imperfections. They can be gently washed, but not scrubbed.
• Semigloss paints are used for walls in high-contact areas such as kitchens and bathrooms, and for trim. They are very durable, washable, and scrubbable, and somewhat shiny.
• Gloss paints have a high sheen, and are the most durable for doors, trim, and cabinets. These washable and scrubbable surfaces will show imperfections.
• Dry erase coatings are used to turn any painted surface into a dry erase board. Clear gloss coatings let the wall color show through.

Stains

Stains are translucent or transparent solutions of dyes or pigments applied to penetrate and color a wood surface. They typically do not provide a protective finish.

Light Reflectances

The light reflectance of a painted surface depends on both its level of gloss and its color. The relatively higher ratio and larger size of particles of pigment in flat paint diffuse light waves more than do the smaller, fewer particles in gloss paint. As we have already discussed, darker colors absorb light rays more than do light colors. In addition, the greater amount of pigment in darker paints decreases their reflectance.

For maximum penetration of daylight, paints with high reflectance should be used on ceilings and walls. High light reflectance levels also help to make the most of the energy used for electrical lighting.

Decorative Paint Finishes

Faux finishes are technically those that imitate natural materials—wood graining and marbleizing, for example—but the term is often used for any decorative painted finish. They are typically made of layers of paint and/or plaster. Special paint finishes also use paint and plaster, but seek to create an original finish rather than imitate an existing material.

There are many types of decorative paint finishes, including the following:

The underside of the floor or roof structure above can be left exposed and serve as the ceiling. More often, however, a separate ceiling material is attached to or hung from a supporting structure. The range of ceiling materials is similar to that for walls, except for those that are too heavy to be hung from an overhead structure.

Plaster and Gypsum Board

Plaster and gypsum board provide uninterrupted ceiling surfaces that can be finished smooth, textured, or painted.

Plaster also affords the opportunity for merging ceiling and wall planes with curved coves.

Both plaster and gypsum board require a supporting framework of wood or metal that is attached to or suspended from the roof or floor framing.

Wood

Wood decking or planks can span the spaces between beams to form the structural platform of a floor or roof. The underside of the planks may be left exposed as the finished ceiling.

Wood planks are normally 5½ inches (133-mm) wide and typically have V-shaped tongue-and-groove joints. Channel groove, striated, and other machined patterns are also available.

With an exposed wood ceiling system, there is no concealed ceiling space.

Metal

On roofs, corrugated steel decking may form the structural platform for thermal insulation and roofing material. Cellular or corrugated steel decking also provides permanent formwork and reinforcement for concrete floor slabs.

Modular

Modular ceiling materials are normally supported on a metal grid suspended from a roof or floor structure. Acoustical ceiling tiles form a square or rectangular grid pattern that may be strong or subtle, depending on the tile design.

Canopies and Clouds

Ceiling canopies are hung from ceilings to define interior spaces. Their gently curved surfaces can be finished to enhance light reflected.

Perforated metal sheets or panels can be suspended in curved or angled designs. They can be backed with acoustical materials to absorb sound.

In commercial spaces, a modular suspended ceiling system is often used to integrate, and provide flexibility in, the layout of lighting fixtures and air distribution outlets. The typical system consists of modular ceiling tiles supported by a metal grid suspended from the overhead structure. The tiles are usually removable for access to the ceiling space.

Acoustical tiles are modular units of fiberglass or mineral fiber. They are available in a variety of square and rectangular styles. Some have aluminum, vinyl, ceramic, or wood faces. Their edges may be square, beveled, rabbeted, or tongue-and-groove. Acoustical tiles come in perforated, patterned, textured, or fissured faces.

Acoustical tiles are excellent absorbers of sound within a room. Tiles are often fire rated, and some are rated for use in high-humidity areas.

Perforated metal pans backed by fibrous batts are available for use with suspended ceilings. With the acoustic backing removed, they can be used for taking in the return air of an HVAC system.

Building codes regulate the flame-resistance of suspended decorative materials in assembly buildings, educational facilities, and dormitories. These decorative materials, such as curtains, draperies and hangings, must be flame-resistant or noncombustible. In some institutional settings, higher standards apply, even including such items as paintings or photographs.

The widespread use of flame retardant chemical finishes to inhibit or resist the spread of fire is undergoing scrutiny, as they appear to be less effective as fire-safety elements than previously believed, and more dangerous to the environment and human health. Polybrominated diphenyl ethers (PBDE) have been used as flame retardants in building materials, furnishings, polyurethane foams, and textiles. PBDE and some other flame retardants have been associated with developmental problems in children, and scientists have recommended that regulations requiring the use of flame retardant finishes be reviewed, and that their use be limited. The apparently deceptive campaign by tobacco and chemical industries to promote the use of flame retardants in spite of flawed research that showed little evidence of their effectiveness has highlighted the need for specifiers to understand health and safety factors of materials.