Finish Selection and Specification
There are thousands of products available for use in interior environments, and each has its assets and disadvantages. The process of selecting the right interior material for the job is sometimes bewildering. The purpose of this book is to serve as a guide for designers to learn about, evaluate, and select materials that will look good, work well, and respect human and environmental needs.
As interior designers select finishes for projects and present them to clients, they assess each alternative for its aesthetic contribution to the design concept. In addition to a material’s appearance, they consider its acoustic properties and light reflectance. The material’s shape, texture, proportion, and scale are related to the balance and symmetry of the space and the harmony of the design. Whether or not a material transmits light influences how it can be used to open or enclose a space. Each selection becomes part of complex relationships between unity and variety, rhythm and repetition, and emphasis and hierarchy. The way a material expresses its function is also part of its aesthetic quality (Figure 1.1
Materials in Trinity Church Undercroft, Boston, Massachusetts
The selection of materials is restrained by codes and regulations that have been instituted to ensure the public’s safety. For example, interior materials can either contribute potential fuel to a fire or resist ignition and flame spread. The materials that line the paths to exits—the means of egress—are especially important.
Interior materials often affect human health and well-being, so designers must review materials for their ability to prevent slips and falls and to cushion surfaces from impact. They check details of product manufacture and installation for exposed sharp edges and shatter resistance. Electrically conductive materials are selected where static electricity is likely to cause a painful shock or affect electronic equipment. Materials that are likely to become very hot or cold require insulation from contact. Where potentially dangerous chemicals are in use, materials are selected to protect both surfaces and people. Designers should avoid materials that expose people to harmful chemicals or unsafe conditions during manufacturing, delivery, installation, use, or disposal, or that degrade indoor air quality (IAQ)
Designers consider how a material will perform under the conditions of the project. They rate materials for durability, colorfastness and fading, and stain and water resistance, and evaluate them for ease of maintenance. Materials may be tested and labeled for light, moderate, or heavy use by their manufacturer.
A material’s availability during a project’s schedule is related to manufacturing schedules and shipping and warehouse arrangements. Custom-ordered items often require longer lead times and additional paperwork. Special government conditions apply to the export or importation of rare and antique materials.
Describing the Properties of Materials
property dependent on the quality and quantity of light; one or more innate colors, and possibly other colors if processed
ability to resist destructive forces, retain original appearance, and continue to function as intended
resiliency or flexibility; the ability to return to initial form after deformation
the three-dimensional quality defined by length, width, and depth; may be linear, planar, or block-like
ability to be formed or shaped; allowing continuous deformation without rupturing or relaxing
ability to form and retain precise, thin, closely spaced elements; depends on strength, durability, and manufacturing process
ability to resist stress, to bend without breaking
relative smoothness or roughness of a surface; may be large- or small-scale
the ease of altering a material from its primary form
The basic functional qualities of materials suggest their appropriate uses. These include safety, durability, comfort, ease of care, fire resistance, and acoustic properties.
Safety issues for interior materials include toxicity, health effects, slip resistance, and shatter resistance. Not only should designers select a material to be safe for use as intended, but they should also consider the unexpected; for example, wired glass will not break when hit by water from a fire hose (its intended function), but it will break if struck hard by a fist, causing cuts and bleeding. It is important to keep in mind that safety concerns change over time; when asbestos was introduced to prevent the spread of fire, its effect on human health was not clearly understood or was not considered.
Durability involves evaluating a material for its ability to stand up to its intended use. Materials may be rated for their resistance to abrasion. Some materials will melt when they come in contact with a heat source; others will deteriorate from contact with alcohol or acetone. Water will damage or weaken some materials, while others will dry out in low humidity. The preparation of the underlying substrate
and the use of proper installation procedures affect the durability of a material, as does its finish.
Comfort is a functional criterion for interior materials that come in contact with the human body. A sturdy but hard chair may encourage short visits in a food court; in contrast, a cozy, large one is more likely to induce lingering. Materials that carry heat away from the human body may be welcome in a tropical climate but can feel unpleasantly cold to the touch elsewhere. The texture of a floor becomes critical for those who spend their workday on their feet.
Ease of care affects a material’s continued performance over time. A material that can be used in a carefully controlled environment with excellent maintenance procedures may not withstand exposure to unsupervised users and less diligent maintenance. Products with frequent, complex, or expensive maintenance requirements often fail to retain their initial appearance, especially if untrained personnel are performing the maintenance.
Fire resistance is such an important topic that designers often limit their initial material selections to those that meet the requirements of fire codes. Codes consider not only the ability of a material to ignite and burst into flame, but also how much smoke it will produce and whether fire will quickly spread across its surface. When exposed to fire, some materials produce toxic chemicals that may be odorless and produce no smoke or flame.
The acoustic properties of interior materials affect the acoustic quality of a space by absorbing or reflecting sound within it, and by transferring sound from one space to another (Figure 1.2
Within a space, a sound generated from one location will spread out and away from its source; this is referred to as diffusion
). It continues to spread and gradually becomes weaker, which is called attenuation
), until it is either absorbed or reflected by an intervening material. In some spaces, a designer will want sound to be r...