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The Bottom Line for Air Quality

The right kinds of flooring can help schools thwart indoor-air-quality problems.

The right kinds of flooring can help schools thwart indoor-air-quality problems.

One of the top five public health hazards, according to the U.S. Environmental Protection Agency, is indoor air quality (IAQ). And it is a problem in more than 50 percent of the nation's schools, a report from the General Accounting Office says. The potential health risks to students, faculty and other employees is causing nationwide concern among facility administrators and planners in school districts.

As one facility administrator says: "The job requires us to be part scientist and part crystal-ball reader. We need to plan buildings with the tools available today that will stand the test of time for the next half century. That's quite a chore!"

So how will today's facility administrators create a school environment that will be conducive to learning, and safe and healthy for the next 50 years?

IAQ specialists have found that the right interior materials, particularly flooring, can help improve air quality. The right match can help schools provide a healthier learning environment and accurately forecast 40-year lifecycle costs of flooring for the building.

Flooring solutions

When selecting floors for school facilities, administrators need to ask five important questions. Can the flooring product:

- Help improve the chief causes of poor IAQ quality - moisture that encourages microbial growth; dust and airborne allergens, and volatile organic compounds (VOCs)?

- Perform IAQ functions for 20 years, half of the normal life cycle of a school building, or will it wear out before the warranty expires?

- Perform its IAQ functions while controlling maintenance costs?

- Improve the learning environment - that is, aid in acoustic, ergonomic and thermal comfort, and control glare from natural and direct lighting?

- Offer any environmental benefits?

Controlling moisture

HVAC-related problems are a major cause of poor IAQ. Improper maintenance can lead to moisture accumulation, which promotes the growth of fungus, mold and bacteria.

Good air-quality management begins with proper air distribution through clean and efficient HVAC systems. This ensures good air filtration, humidity and temperature control. Unfortunately, many HVAC systems are aging and less efficient. But, even when HVAC systems are new and functioning properly, accidents involving moisture intrusion happen. These can range from leaky pipes, spills and flooding to sprinkler-system accidents and breakdowns in the roofing system. Therefore, improvements in HVAC systems are not enough.

How do flooring surfaces handle moisture? Let's look at the differences among three popular types of flooring - vinyl composition tile (VCT), conventional (latex-backed) carpeting and vinyl cushion tufted textile flooring (VCTT).

Out of the three types, conventional latex-backed carpeting is the least moisture-resistant - it absorbs moisture. Since this flooring, when exposed to moisture, can take 10 or more hours to dry (at 20 percent relative humidity), microbials may have time to grow at slightly higher humidity levels.

With VCT, consistent waxing can provide some moisture resistance. However, the seams between the tiles still can absorb enough moisture to cause mold buildup, as evidenced by the visible black lines sometimes found with VCT. Further, scheduled maintenance typically involves wet mopping on a daily basis, another source of moisture intrusion. By contrast, VCTT, with its impermeable backing, resists moisture and, because its seams are permanently welded, allows no penetration for microbial growth.

Something in the air

Inadequate ventilation, dust and airborne allergens, as well as VOCs contained in everyday cleaning solutions, exacerbate IAQ problems. As a result, everyone's breathing is affected, particularly asthmatics and allergy sufferers.

In school tests, VCT was ranked as the lowest performer, because its surface cannot trap dry contaminants and airborne allergens. Allergens are not anchored to the flooring, but instead are reintroduced into the breathing zone by normal activities and foot traffic. By contrast, conventional carpeting and VCTT trap allergens within their textile surfaces until they can be removed by scheduled cleaning. In a test by the Indoor Air Sciences Laboratory, Marietta, Ga., VCTT products removed contaminants 47 percent more effectively than conventional carpeting.

VCT also causes the most concern with regard to VOCs. The product and adhesives generate VOCs near the toxic level when installed. Stripping and waxing VCT creates VOCs and introduces airborne particles into the breathing zone. The EPA recommends that all major maintenance on VCT floors be performed only when the school can remain unoccupied for 48 hours or more.

However, even after two days, some schools report lingering odors. Conventional carpet and VCTT fare better in this category because they can be maintained daily with vacuuming and scheduled maintenance. Low-VOC cleaning agents can be rinsed clean with hot-water extraction. This type of cleaning eliminates the source of VOCs, while reducing allergens, fungi and bacteria up to 99 percent.

Long life

Because most school buildings are expected to function for at least 40 years, flooring needs to last without the need for extensive repair, replacement or maintenance. VCT is the weakest performer here, because it is commonly only warranted for five years, and its maintenance costs are among the highest of any floor covering. Repairs often are not performed because of the high cost to replace individual broken or missing tiles.

Conventional carpet is guaranteed to last 10 years; however, replacement often is required within three to five years. Most replacements are not covered by the manufacturer's "wear warranty." This flooring, according to facility managers, also requires extensive repairs in between cycles.

VCTT is warranted for 20 years (non-prorated), so it requires replacement just once during the life of the school building. Administrators have reported that VCTT holds up extremely well, even after 25 years.

Controlling costs

Maintaining flooring is critical in any school building. In a life-cycle cost comparison of VCT, conventional carpeting and VCTT, VCT proved the most expensive to maintain. Conventional carpet, with flow-through backing that can fail to hold up in heavy traffic, has potential IAQ and performance issues. That can undermine any maintenance savings.

VCTT has a closed-cell vinyl-cushion back that extends the life of the product beyond 20 years and provides a moisture barrier to prohibit the growth of microbials. In a life-cycle cost analysis conducted by a maintenance equipment manufacturer, maintenance costs for a 200,000-square-foot school were reduced by $16,000 a year with VCTT, or $300,000 over the life of the project, when compared with VCT.

Improved learning

Creating an environment that promotes learning is another objective of a school facility manager. Flooring must not heighten the noise level, cause glare or be uncomfortable to walk on. Carpeting absorbs noise, eliminates glare and retains comfort. It also can enhance learning even more because numbers, letters, objects and colors can be integrated into its design.

Local, state and federal governments are emphasizing or even mandating the use of environmentally beneficial products. VCT, broadloom and VCTT flooring differ greatly in this respect, so a discriminating eye and careful research is needed to pick the best product. Begin by checking the composition of the flooring and question the vendor or manufacturer. Does the product contain recycled content? Are performance claims verified in writing from a company officer? Can the material be recycled?

Installation issues

VCT and conventional carpet are installed using wet glue. Because this creates VOC "off-gassing" problems, a school must be unoccupied during installation of these products. VCTT, by contrast, can be applied with a non-wet adhesive. By using a "peel-and-stick" method, VCTT can be installed while school is in session. For example, installers at St. Joseph's Preparatory Academy in Philadelphia worked in rooms adjacent to areas where classes were being taught. In another example, VCTT was installed a few years ago in the prenatal care unit at The Phoenix Children's Hospital while the ward remained fully operational.

Coping with emergencies

The final criterion for evaluating flooring is its expected performance during emergencies - flooding from leaky pipes, rainstorms and other unexpected mishaps. VCT, if newly waxed at the time of a flood, could appear to withstand flooding. However, since VCT is naturally porous, water may seep between the tiles, resulting in mold and mildew, and eventually necessitating total removal.

By the same token, when conventional carpeting is flooded, it should be removed, because it may not recover sufficiently before microbes begin to grow.

VCTT, with its water-impermeable backing keeps moisture at the surface, and can be cleaned without removal. In a school in Texas, a sprinkler leak last year flooded one of the key corridors just days before the school was to open. Instead of removing the VCTT, maintenance crews were able to clean it with hot-water extraction - restoring VCTT to its original condition.

Facility administrators face considerable challenges when it comes to maintaining good air quality in their schools. Knowing about the different types of flooring and their performance characteristics can help education professionals make wise choices.

Vinyl cushion tufted textile (VCTT) flooring has been described as an advanced hybrid of impermeable sheet vinyl with welded seams and comfortable carpet. This soft-surface flooring has a moisture-impermeable, closed-cell cushion backing. The backing provides long-term resiliency and comfort, and acts as a moisture barrier that prevents the growth of fungus and bacteria.

The vinyl cushion backing puts to rest the notion that face weight determines performance. Its low-tufted (type 6.6 nylon) densely constructed (over 100 stitches per square inch) textile surface, with face weights as low as 14 ounces per square yard, challenges conventional wisdom of the industry norm of 26 ounces per square yard.

Its warranty is non-prorated for 20 years, with some installations still going strong after 30 years with no need of replacement or repair.

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