Using stone and ceramic tile for a healthy building environment
Sick building syndrome is the result of the off-gassing of volatile organic compounds that may be present in building materials. These can include chemicals, odors from fibers or fumes from building materials as they are curing and drying. Many of the building materials used in today's construction methods contain products that can cause some of the problems mentioned at the outset. There have been many questions and potentially even more solutions to these issues. While the construction business and the materials and methods used to build our buildings are vast, I will focus on just one area. That is the use of stone and tile as a finish material on floors as opposed to other types of flooring finishes such as carpeting, resilient or wood flooring and as a wall finish as opposed to using paint, vinyl wall covering or fabric wall covering. I will also answer several questions in this discussion. Why is stone and tile healthier for the building environment? Why is there a movement towards creating a healthier building environment? Let's examine the trend towards healthier and â€œgreenerâ€ buildings.
Background on the Green Building Movement
The term â€œgreenâ€ - when used in discussions that concern buildings and construction - signifies healthy and environmentally friendly products and buildings. Before we can address the reasons why stone and ceramic tile should be used as a finish material, we need to understand the green building movement. The respiratory and allergic reactions of building occupants can be traced back to reactions that they may have with some of the products that are in the structure. In one study, â€œit was determined that people are indoors approximately 90% of the time.â€ (Ahuja, 2004, p.2) With that in mind, good indoor air quality is very important. The design community has long recognized this fact, and it has inspired federal and state organizations to create programs that are designed to target the issue of indoor air quality.
As of 2005, there are â€œ29 programs currently runningâ€ that have established guidelines to address this issue (R. Dooley, 2005, p. 1). One example of a state that began to enact standards for clean indoor air is California. For example, note what the State of California Environmental Protection Agency (EPA) had to say on the matter of finish materials and adhesives that contain formaldehyde (a known polluter of indoor air): â€œOne of the most common pollutants found in indoor air is formaldehyde, a carcinogen often emitted by pressed-wood products, adhesives and fabrics. It can cause severe headaches, sensory irritation, nausea, rashes and cancer. In its testing, the State of California EPA OEHHA has identified up to 60 hazardous substances, including formaldehyde, that are commonly used in buildings. The project specifications for the Capitol Area East End Complex have established maximum modeled indoor-air chemical concentrations for those compounds and formaldehyde.â€ (Air Quality Sciences, 2002, p.25).
More and more end-users and design professionals are recognizing that a healthy building environment is an essential part of the community. Hand in hand with the health issues of our buildings comes the sustainability and quality of building materials used. What does this actually mean? Simply put, sustainability can be defined as how long will the products used in a structure last before they have to be replaced or repaired. For example, for the purposes of our discussion, how long will tile wall cladding last as opposed to a coat of paint or an application of vinyl wall covering? Along with using products that do not harm the environment or humans, sustainability is also becoming a hot issue within the building community. The health and sustainability issues go hand in hand, since the frequency in which finishes are replaced impact the indoor air quality of buildings. With that said, the use of environmentally friendly products makes sense.
Environmentally friendly productsIn today's construction marketplace, the phrase â€œenvironmentally friendly productâ€ is thrown around a lot. But what does this actually mean? Environmentally friendly products are ones that do not harm the space that humans occupy and do not have any adverse impact on the ecology or environment during their harvesting, manufacturing, installation, curing/drying and while in service. In making the determination for whether a product is environmentally friendly or not, we can ask the following questions: Does the material break down over time? What is its half-life? How long will it off-gas? How often does it need to be maintained and/or replaced? For example, there are some materials in the plastics family that just do not break down easily. They can stay in a landfill for hundreds of years. There are several types of flooring products that fall into this category (e.g. vinyl composition tile, linoleum, rubber flooring). In addition, when these types of flooring materials are installed with a urethane type adhesive; they can be potentially dangerous to the environment for many years, even when they are discarded.
What is great about stone and ceramic tile is that they are mainly composed of basic materials that are found in the earth. There is not much that needs to be done to a slab of marble, limestone, slate, sandstone, granite or quartz - other than to cut it to size and alter its finish as needed. The same applies to ceramic tile, where the ingredients that go into it are mainly clay and shale that are then pressed or extruded into shape and then fired in high temperatures to achieve a very dense and durable finish. Meanwhile, the cost of other types of flooring and wall finishes continue to increase.
Stone and tile are also considered to be â€œclean fill.â€ If for any reason stone or tile is removed (and this is usually only because it looks dated), it can be buried in a landfill and will not harm the ecology or the environment. Unlike the adhesive mortars that are used to install resilient and wood floors or carpeting, stone and tile adhesives are typically Portland cement based and do not pose any danger to the environment. They are inert once they harden, and they do not off-gas or emit any Volatile Organic Compounds (VOC).
Volatile Organic CompoundsVolatile Organic Compounds are ingredients contained in building materials that may escape as they air dry or cure. As building materials cure or dry, an odor may be emitted. This is what may cause a person to develop reactions to the materials in a building. You know that new car smell or that new carpet smell? VOCs are part of that scent. It is the off-gassing of the Volatile Organic Compounds that creates these respiratory or allergic reactions. Some of the ingredients in building materials that off-gas are formaldehyde, ozone, particles and VOCs. These ingredients exist in over 2,000 chemicals (Ahuja, 2004, p. 2). Let's see why stone and tile are advantageous in the area of Volatile Organic Compound emission.
Advantages of stone and ceramic tileWhen a comparison is made of the Volatile Organic Compounds contained in floor and wall finishing products, it is obvious to see why stone and tile is the better finish choice over the others. To demonstrate this fact, compare the following types of finishes and their Volatile Organic Compound content (California Department of Health Services, 2004, p.3, 6, 7):
In addition to the finishes mentioned above, the adhesives used for the application of the materials can also contribute to the Total Volatile Organic Compounds (TVOC) in a building environment. The following are typical Volatile Organic Compounds for the adhesives used for some of finishes listed above (California Department of Health Services, 2002, p.7).
- Stone and ceramic tile installed with a typical latex fortified Portland cement-based mortars:
<2.39 grams per liter
- Multipurpose carpet and resilient flooring adhesives, including a typical carpet or resilient flooring material:
Multipurpose latex adhesive
976 grams per liter
Synthetic "low-VOC" adhesive
698 grams per liter
As indicated, the TVOC contained in a typical stone and tile installation is practically nil. When compared against the other types of finishes, stone and tile contribute to a healthier building environment. Manufacturers and promoters of the other finish types report that the off-gassing of Volatile Organic Compounds will diminish as time passes, and that is true to an extent. There have been many strides made to manufacture these types of finishes and adhesives with lower Volatile Organic Compound content. Several of the larger watchdog agencies have set stricter guidelines to ensure that this happens (South coast indoor air quality district, 2001, p.2). However, these types of finishes are still significantly higher in Volatile Organic Compound content when compared to stone and tile. In addition, these other finishes do not have the same durability and sustainability. In fact, carpeting and resilient flooring have to be replaced every seven to 10 years or so (The Old Farmer's Almanac, 2005, p.1).
Stone and tile have greater sustainability. In fact, many other cultures in Europe, Asia, the Middle East, Central and South America have been using stone and ceramic tile for years in applications where Americans typically would not use these materials. Most of the baths, kitchens, and foyers in these cultures are tiled from floor to ceiling, whereas in our culture, it may be limited to just the floors and base or just used in wet areas. One of the reasons for this is that stone and tile are easier - and cheaper - to maintain. So even with a higher initial cost, stone and tile are actually more economical over the long term.
The per capita consumption of stone and tile in non-U.S. cultures is almost three to four times the consumption than in the U.S. (Lindsay, 2001, p.65). This is also evidenced by the fact that stone and tile products have been in place on some structures for hundreds, if not thousands, of years. Can anyone make the same claim for other types of finish materials used in or on buildings? Stone and tile are also good fighters against mold and mildew. They are not food sources for mold and mildew, whereas many of the other finish types are either made from ingredients that are food sources for mold, or the finish itself is a food source for mold. In addition, stone and tile are inherently water resistant, whereas these other finish types absorb and degrade when exposed to moisture, further adding to the mold issue. A building owner certainly would rather have finishes in their structures that are resistant to the threat of mold and mildew.
ConclusionIn light of all the information that has been gathered and presented, stone and tile are the natural choice to be used as a finish material that will provide long-lasting benefits. These benefits include a long in-service life cycle, no negative contribution to indoor air quality and materials that are very easy to maintain. When compared to other finish materials, the clear choice is to use stone and tile as a finish material in today's building environments.
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