# T ECHNICAL 

# S UPPORT 

# D OCUMENT

FOR



# A MENDMENTS TO



# COMAR 26.11.35

A DHESIVES AND 

# S EALANTS

F EBRUARY 

## 12, 2009

M ARYLAND 

## D EPARTMENT OF THE 

## E NVIRONMENT 

### 1800 Washington Boulevard Baltimore Maryland 212302 

### This Page Left Intentionally Blank

### TABLE OF CONTENTS

Purpose and Background......................................................................................4

Summary of Amendments.....................................................................................5

Sources Affected.....................................................................................................5

Technology Analysis ..............................................................................................5

Impact on Ambient Air Quality............................................................................5

Economic Impact ..................................................................................................6

Appendix A.............................................................................................................7 The Low-Slope Commercial Roofing Industry in the Northeast United States and the Ozone Transport Commission Model Rule for Adhesives and Sealants: A Study of Risks and Options for Effective Implementation

3Background

Maryland's current requirements are ba sed on the 2006 Ozone Transport Commission (OTC) model rule for adhesives and sealan ts. The OTC rule follows the reasonably available control technology (RACT) and best availabl e retrofit control technology (BARCT) determination by the California Ai r Resources Board (CARB) developed in 1998. Adhesives, sealants, adhesive primer s, and sealant primers are used in manufacturing, packaging, constr uction, and installation of di sparate materials such as metal, wood, rubber, plastic, ceramics, fiberg lass and composites. An adhesive is any

material used to bond two surfaces. A sealant is a material with adhesive properties that is used primarily to fill and seal durably, openings between two surfaces.

The regulations affect a large number of s ources and materials a nd provide significant reductions of VOCs. Due to the large scale impact of the regulations, the Department adopted the standards after an extensive analysis and outreach effort in 2007. The purpose was to give affected sources and manufacturers sufficient time to test new materials and make process changes to m eet the new standards. The Adhesives and

Sealants Council raised concerns to States about performance concerns for roofing adhesives when applied at lo wer temperatures. ERA and th e EPDM Roofing Association requested more time for testing and for trai ning users to work with lower VOC products during the colder, non ozone season months.

The Department requested OTC to review thes e concerns in order to gather a multi-state perspective on this concern. The OTC did not recommend or make changes to the model rule after its review. The OTC, after technical review, left it up to the states to decide their course of action. During, and shortly foll owing the OTC review process, four states and Washington D.C. decided to grant a non-oz one season exemption fo r the initial years of implementation.

The Department continued to meet with manufacturers, installers and association representatives and requested additional information in support of their position. As a result of discussions and in order to pr ovide more time for training, the Department agreed to provide a limited exemption for th e non-ozone period during the initial phase of implementing the regulation.

Purpose of Amendments

These amendments exempt single-ply roof me mbrane installation a nd repair adhesives, single-ply roof membrane seal ants and single-ply roof memb rane adhesive primers from the standards for VOC content during th e non-ozone season for the years 2009, 2010 and

2011. In 2012 the standards for VOC content for these materials are applicable through out the year. These amendments affect manufact urers, suppliers, inst allers and users of single-ply roofing materials.

4Regulation Amendment Summary

COMAR 26.11.35.01 Applicability and Exemptions is amended to limit the applicabilityof VOC standards for single-ply roof membrane installation and repair adhesives, singleply roof membrane sealants and single-ply roof membrane adhesive primers according to the following schedule:

(1) For the year 2009, from May 15 through September 15;

(2) For the years 2010 and 2011, from May 1 through September

30: and

(3) On and after January 1, 2012.

Affected Sources

These proposed amendments affect manufactur ers, suppliers, installers and users of single-ply roofing materials.

Technology Analysis

Bonding adhesives are used in single pl y roofing applicatio n. The EPDM Roofing Association conducted a study on the feasibil ity of using bonding adhesives during the low temperature periods in the Northeast. Th e study states: “These bonding adhesives are composed of polymeric resins suspended in a variety of solvents. The majority of the solvents in single-ply bonding adhesives used today contain VOCs at rates higher than the 250 g/l standard establishe d in the OTC Model Rule. Ex amples of these solvents include toluene, hexane and heptane. Because these solvents volatize at relatively low temperatures, they allow the effective appli cation of single-ply roofing membranes within a relatively wide temperature range – from below freezing up to 100 o F and beyond. Because of this wide useful temperatur e range, bonding adhesives using high VOC solvents are the preferred product choice for the commerc ial roofing contractor.” The study is included in Appendix A. New low VOC roofing adhesives are in development which should allow the eff ective application of single-ply roofing

membranes under cold weather conditions.

Impact on Ambient Air Quality

The proposed amendments are designed to provide additional time for training and adaption to the use of new roofing adhesive materials. Roofing ope rations are performed at a lower rate during the non-ozone season. The release of VOCs during the non-ozone season has less of an impact upon the environm ent. The maximum benefit will continue to be provided in ozone season.

5Economic Impact

These proposed regulatory changes are design ed to provide relief for training and adaptation purposes and at the same time bus inesses can continue to use conventional materials during the non-ozone season. The amendment will lessen the economic impact

on the affected sources in the in itial stages of implementation.

6

### Appendix A

The Low-Slope Commercial Roofing Industry in the Northeast United States and the Ozone Transport Commission Model Rule for Adhesives and Sealants:

A Study of Risks and Options for Effective Implementation

Prepared for the EPDM Roofing Association

For submission to the Maryland Department of the Environment

January 12, 2008

Dr. James L. Hoff, DBA

TEGNOS Research, Inc

3575 Seminole Dr. 609 Post Way Carmel, IN 46032 Tubac, AZ 85646

Tel 317-679-1542

www.tegnos.org

7The Low-Slope Commercial Roofing Industry in the Northeast United States and the Ozone Transport Commission Model Rule for Adhesives and Sealants:

A Study of Risks and Options for Effective Implementation

TABLE OF CONTENTS Page

1. INTRODUCTION 3

2. STUDY OBJECTIVES 5

3. ANALYSIS 6

A. VOC Reduction in Roofin g Systems: Technology Review

B. Climatic Factors: Ca lifornia v. Northeast U.S. C. Product Usage Factors: California v. Northeast U.S. D. VOC Emissions and Commercial Roofing Adhesives

4. OVERALL RISK ASSESSMENT 14

A. Wind & Storm Risks B. Training & Performance Risks C. Seasonal Work Disruption and Uncertainty

5. CONCLUSIONS 16

6. RECOMMENDATIONS 18

Copyright 2007 TEGNOS Research, Inc.

81. INTRODUCTION

As part of a regional effort to achieve Fe derally-mandated eight-hour ozone standards in the Northeast and Mid-Atlantic regions of the United States, the Ozone Transport Commission (OTC) developed a Model Rule for Adhesives and Sealants (OTC Model Rule). The provisions of this model rule limit emissions of volatile organic compounds (VOCs) from adhesives, sealants and prim ers. The OTC Model Rule achieves VOC reductions through two basic mechanisms: 1) sa le and manufacture rest rictions that limit the VOC content of specified adhesives, sealants and primers sold in the state, and 2) use restrictions that apply prim arily to commercial/industrial applications. The OTC Model Rule was published by the OTC in 2007, w ith the stated goal of adoption and enforcement by individual states and local po llution control districts on or before January
1, 2009.

The OTC Model Rule is essentially identical to a similar model rule published by the California Air Resources Board (CARB) in 1998. In the years 1998-2001, the provisions of the CARB rule were adopted in regul atory form by various air pollution control

districts in the state of Ca lifornia. Although the CARB model rule is described in the preamble of the OTC Model Rule to be a “r easonably available control technology,” the CARB rule was developed in region of the United States with climatic and economic factors that may differ signi ficantly from the Northeast Un ited States. In addition, these climatic and economic factors may have a si gnificant influence on the effectiveness and overall impact of the OTC Model Rule on the environment and economy of the

Northeast.

The commercial low-slope roofing industry may provide an importa nt example of how a

model rule based on the climatic and market demands of California may adversely impact

such a rule’s effectiveness in other areas of the countr y. Although it accounts for a relatively small portion of the larger economy within the Northeast United States, the commercial roofing industry provides a vital service to assure public safety and support commerce. By assuring the weather-tight inte grity of buildings, properly installed and maintained commercial roofs protect the public from damage from storms and minimize long-term health problems associated with mold and other problems associated with leaky roofs. And by developing application technologies that can be utilized throughout the entire year in the Northeast United St ates, commercial roofers enable the larger commercial construction industry to operate on a year-round basis.

Unfortunately, many of the adhesives devel oped by the roofing i ndustry to meet the requirements of the California -based model rule were also developed to be effective primarily within the climatic and market conditions that occu r in California; and some of these conditions differ significantly from conditi ons and practices in the Northeast. As an example, the adhesives used to secure mode rn roofing membranes to the roof surface (“bonding adhesives”) are generally effective and can only be applied when ambient air temperatures are at or above 40 o F and rising. While average minimum daily temperatures in California usually exceed the 40 o F minimum, this temperature is generally not

9available in the Northeast for many fall, wi nter and spring months. As a result, the conditions that currently allo w the commercial roofing i ndustry to provide safe and durable roofing systems for the Northeast in al l seasons of the year may not be available with the promulgation of the OTC Model Ru le in its current form. And although the commercial roofing industry contributes a relatively small portion of overall VOC emissions in the Northeast, the industry may bear a disproportionately negative impact under the OTC model rule. And in turn, this impact may significantly impede the roofing industry’s effectiveness in keeping buildings dry and allowing commercial construction activity to proceed on a year-round basis.

Because of concerns regarding the overal l impact of the OTC Model Rule, several organizations representing the commercial roofing industry have commissioned this study of the OTC Model Rule and its impact on commercial roofing in the Northeast.

102. STUDY OBJECTIVES

A. Identify the available technologies for re ducing VOCs in commercial roofing systems and evaluate their suitability and effectiveness for use in the Northeast United States.

B. Identify and quantify the differences between conditions in the state of California and Northeast states that may affect the overa ll utility and effectiveness of the OTC Model Rule as it applies to the commercial roofing industry.

C. Identify and quantify and potentially signi ficant adverse effects of the OTC Model Rule and commercial roofing in regard to commerce and public safety in Northeast

states.

D. Identify possible options that may maxi mize the effectiveness of the OTC Model Rule to reduce roofing-related VOC emi ssions in Northeast states while also maintaining the effectiveness of the roofing industry to perform its role of protecting the public and promoting commerce.

113. ANALYSIS

A. VOC Reduction in Roofing Systems: Technology Review

VOCs in modern low-slope commercial roof ing systems come primarily from three sources: 1) splicing adhesives used to bond the edges of roofing membranes to each other, 2) bonding adhesives used to bond the surface of roofing membranes to roof substrates and walls, and 3) sealants used to seal edges and terminations of roofing membranes to walls and roof projections. Of the three VOC product categories, two categories already employ low-VOC (less than 250 g/l) formulations throughout the

United States and North America. In the case of splice adhesives, almost all single-ply roofing seams are currently mated using eith er 100% solids tapes (in the case of EPDM or rubber roofing materials), heat-welding (in the case of PVC / TPO or thermoplastic roofing materials), or hot as phalt (in the case of traditional asphalt and modified bitumen roofing materials). In the case of sealan ts, low-VOC, 100% solids products are both widely available and widely used throughout North America. Given the widespread use of low-VOC splicing and sealing technol ogies, the remaining category of bonding adhesive appears to be accountable for th e overwhelming majority of VOCs produced in commercial roofing. This is due to both th e current typical high- VOC content of the adhesives as well as the overall quantity of roof surface area requiring bonding as compared to the relatively small areas requiring panel seaming and edge sealing.

The amount of VOCs generated by bonding adhesi ves may vary with the type of roofing system and the type of adhesive employed. In the case of asphalt roofing membranes, hot asphalt is the predominant adhesive, either applied with a mop to the membrane surface or derived from the membrane using a roof ing torch. In the case of single-ply membranes, the predominant adhesives are cont act adhesives that are sprayed or rollerapplied to both the membrane surface and th e roofing substrate. These bonding adhesives are composed of polymeric resins suspended in a variety of solvents. The majority of the solvents in single-ply bonding adhesives used today contain VOCs at rates higher than the 250 g/l standard establishe d in the OTC Model Rule. Ex amples of these solvents include toluene, hexane and heptane. Because these solvents volatize at relatively low temperatures, they allow the effective appli cation of single-ply roofing membranes within a relatively wide temperature range – from below freezing up to 100 o F and beyond. Because of this wide useful temperatur e range, bonding adhesives using high VOC solvents are the preferre d product choice for the comme rcial roofing contractor.

Roof membrane bonding adhesives may also be formulated using low-VOC solvents, including acetone and water. Because these solvents do not volatize at low temperatures, their operating range is typical ly limited to temperatures consistently at or above 40 o F. In addition, because they tend to volatize more slowly than high-VOC solvents, they are much more affected by ambient conditions, such as relative humidity and solar shading factors. As an example, a roofing membrane exposed partially to the sun and partially in the shade may “over dry” on the sunlit surfac e while the shaded surface remains too wet

for installation. If the adhe sive is allowed to dry too long, the adhesive bond may be weakened and the overall wind uplift resi stance of the roofing system may be

12compromised. And if the adhesive is too wet when the membrane is installed, the roof will likely “blister,’ also compromising overall adhesion. As a consequence, the effective use of these adhesives – even under optimal temperature conditions – requires significant awareness, training and experience on the part of the roofing crew.

Currently, high-VOC bonding adhesives domin ate the commercial membrane roofing market. Shipping reports from EPDM Roofi ng Association (ERA) members indicate that over 95% of all single-ply bonding adhesives so ld in the United States continue to employ high-VOC formulations. The only region of the country where low-VOC bonding adhesives currently dominate is the st ate of California, where low-VOC bonding

adhesives have been mandated since the late 1990s. This would appe ar to indicate that customer preference will be difficult to ch ange without a mandated regulation. However, this also suggests that littl e learning, preparation or adapta tion to the spec ial application requirements of low-VOC adhesives has occurred outside of mandated regions.

The commercial roofing industry is currently working on several technologies that may reduce the VOC content of bonding adhesives, bu t these technologies have not yet been tested and demonstrated on a large scale, es pecially in the Northeast United States. Examples of these technologies include polyurethane foams, 100% solids, highmolecular-weight solvents, and thixotropic compounds. These technologies appear to offer value in addressing the needs of the r oofing industry, especially in adapting to the extreme temperature range required for roof top application. However, each of these technologies also comes with risks that have not yet been fully eval uated. Examples of these risks include 1) applicator familiar ity and training, 2) long-term durability and service life, and 3) health concerns with some of the chemicals involved.

In addition, all of thes e alternative technologies carry cost penalties between two and four times the cost of current high-VOC bonding a dhesives. Although cost may not be an overriding consideration in view of the larger mission to reduce the environmental impact of VOCs, this cost differential must be consider ed in terms of its past effect in restricting research and new product development. Becau se roofing contractors and their building owner customers have been very reluctant to pay the current cost premiums required by alternative technologies, roofi ng manufacturers have been unable to conduct extensive testing and marketing of these products. Given sufficient development time, however, roofing manufacturers appear to be confident that a succe ssful transition can be made from today’s high-VOC bonding adhesives to new low-VOC alternatives that can successfully address cold temperature applications.

B. Climatic Factors: Ca lifornia v. Northeast U.S.

A comparison of climate between California an d Maryland indicates both similarities and contrasts. Figure 1 compares average monthly minimum and maximum temperature between cities in southern California (L os Angeles), northern California (Oakland), coastal Maryland (Baltimore), a nd inland Maryland (Hagerstown).

13Figure 1: Monthly Average High and Low Temperatures

(Source: The Weather Channel)

44 47 57 68 77 86 91 88

81

70

59

49

29 31 39 48 58 68 73 71

64

52

42

33

10 20 30 40 50 60 70 80 90 100

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 68 70 70 73 75 80 84 85 84 79

73

67

48 50 52 54 58 61 65 66 65 60

53 48

10 20 30 40 50 60 70 80 90

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

57 61 63 66 69 72 73 73 75 72

64

58 Las Angeles, California

Ozone Season (Northeast US) o F

45 48 49 51 53 56 57 58 58 55

49 45

10 20 30 40 50 60 70 80 90

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Oakland, California

Ozone Season (Northeast US) o F

Ozone Season (Northeast US) o F Baltimore, Maryland

Hagerstown, MD

38 42 52 63 74 82 86 84

77

66

54

43

21 23 31 41 51 60 64 62

55

43

35

27

10 20 30 40 50 60 70 80 90 100

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ozone Season (Northeast US) o F

Operating Range of VOC-Compliant Single-Ply Roofing Bonding Adhesive under OTC Model Rule (<250 gm / l) Average High Average Low

14During the summer months of June through August, average high and low temperatures for Los Angeles and Baltimore are nearly id entical, while Oakland and Hagerstown are slightly cooler. During the late spring and ear ly fall, the temperature differential between

the two California cities and the two Maryland cities begins to widen, as both the average high and low temperatures in the Maryland ci ties decline below the averages for the California cities. However, even during the ea rly fall (September) and late spring (May), both high and low average temperatures for th e Maryland cities fall within the operating range for currently available VOC-compliant membrane bonding adhesive technologies mentioned previously. It should be noted th at the period from May through September, when average temperatures for the Maryland ci ties fall within the range of current VOCcompliant bonding adhesive technology, coinci des with the “Ozone Season” for the

Northeast United States as defined by the Ozone Transport Commission.

The average temperature differentials between the two states increases further, however, during the late fall, winter, a nd early spring, with average te mperatures for the Maryland cities declining a nd dropping below 40 o F. During the months from November through March, average temperatures for the Maryland ci ties are either well below or barely at the minimum operating temperatures required fo r current VOC-compliant roofing membrane adhesive technology. It should be noted, however that the period from October through April, when average temperatures in Wash ington drop below the ra nge of current VOCcompliant bonding adhesive technology, falls outside the “Ozone Season” for the

Northeast United States as defined by the Ozone Transport Commission.

15The challenges of the winter months in th e Northeast are even more pronounced in terms of low temperatures, as shown in Figure 2 fo r the cities of Baltimore and Hagerstown:

Figure 2: Monthly Record High and Low Temperatures

(Source: The Weather Channel)

Even during the most extreme events recorded, the high and low temperatures in the California cities still fall within the op erating range for currently available VOCcompliant membrane bonding adhesive technologies throughout the entire year. In Maryland, however, the designated “ozone” months of May and September, which appear to be hospitable to low-VOC bonding ad hesive in terms of average temperatures, may frequently experience low te mperatures well below the 40 o F minimum for successful application of low-VOC bonding adhesives. 78 81 86 95 96 99 104 103 99 93
84 78

-17 -9 2 18 30 37 42 40

29

18

8

-6

-20

0 20 40 60 80 100

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Hagerstown, MD

Ozone Season (Northeast US) o F

Operating Range of VOC-Compliant Single-Ply Roofing Bonding Adhesive under OTC Model Rule (<250 gm / l) Record High Record Low 79 84 97 98 100 105 107 105 102 97

87 85

-4 -7 11 15 32 46 54 52

40

30

12

-2

-20

0 20 40 60 80 100

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Baltimore, MD

Ozone Season (Northeast US) o F

16C. Product Usage Factors: California v. Northeast U.S.

1) Historical Development of the U.S. Roofing Market . Prior to the development of modern single-ply r oofing membranes in the 1970s and 1980s, almost all commercial

roofs in the United States were constructed of asphalt materials, typically in redundant layers of roofing “felt” embedded in progres sive applications of hot asphalt. However,

the dominance of traditional as phalt roofing began to decline during the 1970s due to an

unusual confluence of events. The Arab Oil Emba rgo forced refineries to derive more and more gallons of gasoline from every barre l of oil. As a consequence, the asphalt remaining at the “bottom of the barrel” c ontained fewer plastic elements and became more brittle. Increasing concerns about the he alth hazards of asbestos exerted a similar effect on roofing felts, as asbestos was repla ced with weaker organic materials. The oil embargo also increased concerns about ener gy conservation, drivi ng up the thickness of

roof insulation. As roof insulation thickne ss increased, the over lying asphalt roof membrane became isolated thermally from the remainder of the building. As a result of this “thermal isolation,” the roofing membra ne became subject to increasing temperature swings from solar heating duri ng the day and freezing temperat ures at night. Frequently, the embrittled asphalt and the weakened roofing felts frequently were unable to accommodate the thermal movement produced by these temperature swings.

Starting in the 1970s single-ply roofing membranes made from rubber and plastic materials began to supplant traditional flat asphalt roofing. In place of redundant layers of felts, these materials provided a single, monolithic waterproofing layer. And instead of hot asphalt, single-ply membranes were frequently attached to the roofing substrate with contact adhesives. During the 1980s, sales of single-ply membranes began to accelerate, driven by the growth of one type of membra ne in particular: EPDM, or rubber roofing. By the end of the1980s, annual sales of EP DM roofing membranes had grown to over one billion square feet, or approximately 1/ 3 of the entire low-sl ope commercial roofing

market in the United States.

2) Regional Market Differences . The strong growth of EPDM roofing was not uniform throughout the United States, however. In region s with infrequent fr eezing temperatures such as the West and Southwest, asphalt ma terials continued to dominate. However, in regions with frequent freezing temperatures such as the Midwest and Northeast, EPDM’s share of the commercial roofing market exce eds its 33% national average. The trend

started in the 1980s continues to be demonstrat ed today in industry shipment statistics. Figure 3 compares the market share of EP DM, asphalt, and other single-ply (PVC & TPO) roofing membranes for the state of Ma ryland as compared to California in 2006.

17Figure 3: Annual Commercial Roofing Membrane Usage (Millions of Square Feet)
(Source: SPRI 2006)

29,000,000 22,000,000

12,000,000 55,000,000 3,000,000

132,000,000

New Jersey California

EPDM PVC/TPO Asphaltic 2%

29%

69%

35%

19% 46%

In the state of California in 2006, EPDM r oofing accounted for only 2% of total lowslope roofing installa tions, as compared to 69% for asphalt membranes. However, in Maryland the ratio is significantly differe nt, with EPDM membranes accounting for over 1/3 of all roofing projects. Looking at the current mix of roofing materials used in Maryland and California, the data suggests that product preferences are influenced by climate. In Maryland, where temperature swings and freeze-thaw cycle are intense, the high flexibility of rubber roofing appears to be a significant cons umer choice to avoid premature roof failure due to cracking or splitting.

3) Regional Training / Experience Issues . Regardless of the factors behind the differences in product choice between Califor nia and Maryland, th e fact that rubber roofing, which is a major product of choice in Maryland, has been rarely used in California may bring into question the OTC assumption that the experience of the California market provides a “reasonably av ailable control technology” that can be immediately implemented in either Maryla nd or the Northeast. Although Maryland is much smaller in terms of area and populati on, every year over 22 million of EPDM roofs are installed as compared to only 3 million sq uare feet in California. Because of the paucity of EPDM installations in California , it takes over 7 years of roofing experience

18with EPDM in California to equal the experi ence – and risk - with EPDM installations occurring in Maryland in a single year.

Just as little practical experience relevant to the Northeas t may have been obtained from

California’s mandate for low-VOC bonding adhesives, little if any effort has yet been made to provide training for Maryland roofi ng workers in regard to effective application of low-VOC products. According to a survey of Maryland’s largest commercial roofing contractors, little or no formal training on low-VOC adhesives has yet been undertaken. In addition, shipment records of members of the EPDM Roofing Association indicate that fewer than 1000 gallons of low-VOC bondi ng adhesives are shipped annually to Maryland– indicating that Ma ryland contractors and thei r crews have little or no experience with low-VOC a dhesives at this time.

The lack of contractor tr aining and experience with low-VOC bonding adhesives is particularly worrisome since the total numbe r of roofing workers involved in roofing

installation is relativ ely high. The consensus of roof ing contractors contacted and interviewed for this study i ndicates that approximately 20,000 workers may be involved in roofing applications in Maryland annuall y. In addition, the c ontractors report high turnover rates that may increase this number, especially in terms of training needs.

194. OVERALL RISK ASSESSMENT

A. Wind & Storm Risks

The risk factors associated with compromised roof installation – es pecially in terms of adhesive securement – also app ear to be higher in the Northe ast than in California. As illustrated in the 50-year design wind speed ma p of the United States shown in Figure 4, large portions of Calif ornia (especially the most populated areas) fall within the lowest wind design category of 70 miles per hour. In contrast, many areas of the Northeast fall within a much higher wind speed of 90 to 100 miles per hour, with even higher wind speed considerations along Atlantic coas tal areas.

Figure 4: Building Code Design Wind Speeds in the United States

(Source: Uniform Building Code)

In addition to higher design wind speeds, th e consequences of wind-related roofing failures may be much more severe in the No rtheast, where almost all extreme winds are associated with the cyclonic storms and hurri canes that may drop as much as 12 inches of water in a single day. As a result, what might be a minor wind incident during a hot “Santa-Anna” gust in Californi a may be a major disaster causing extensive building damage compromising occupant safety dur ing a significant wind and rain event in Maryland.

20B. Training & Performance Risks

Although roofing accounts for only about 6% of the total cost of a building, the National Roofing Legal Resource Center reports that roofing problem s account for over 25% of all construction-related litigation. This high frequency of litigation has made roofing contractors especially conservative when it comes to the selection of roofing materials and methods. In fact, the market data s howing that roofing co ntractors in Maryland prefer EPDM roofing in over 35% of all appl ications suggests that the contractors have established a definite preference for the produc t they believe will perform the best (and keep them out of the courts) given the speci fic climatic factors in Maryland and other parts of the Northeast.

Because of differences in application skills and methods, any abrupt change made by the roofing contractor community could incr ease the risk of compromised roofing installations and roofing-re lated construction litigation. If roofing contractors in Maryland and the Northeast were to decide to return to a greater reliance on traditional asphalt systems in order to minimize their risk, they would have to re-train a workforce of approximately 20,000 roofing crew members to re-gain the traditional skills associated with applying and controlling hot asphalt. If the roofing contractors decide to stay with EPDM systems and immediately embrace lo w-VOC bonding adhesives, the same 20,000 crew members will again need extensive traini ng to assure the prope r application of an adhesive system little-used and litt le-understood in the Northeast.

C. Seasonal Work Disruption and Uncertainty

With the exception of extreme snow and ice conditions, roofing work in Maryland and the Northeast continues throughout the year regardless of the season. If roofing

contractors are forced to move too quickly to low-VOC bonding adhesives that are unsuitable for application at temp eratures close to or below 40 o F, it is likely that roofing crews will be unable to work at all during the late fall, winter and early spring. In addition, even during the late spring and early fall, unsuitable daily temperature conditions may occur at a frequency that ma y make it unprofitable for roofing contractors to assemble and maintain crews available for work even on days when temperatures are favorable. This situation may not only in crease unemployment among roofing crew members, but the disruption might spread to the entire commercia l construction industry, as partially completed buildi ng sit empty and exposed to th e weather until temperatures were suitable to install roofing materials.

215. CONCLUSIONS

The same data in this study that identify the risks associated with an abrupt switch to lowVOC bonding adhesives for roofing in the North east may also identify the best approach to avoid many of these financial and public safe ty risks. At the time of the year when ozone formation is of particular concern to th e citizens of the Northeast, especially during the peak ozone months of July, August and September, temperature conditions are generally suitable for the use of current low-VOC bonding adhesive technology without overly compromising current roofing practice. And during the colder seasons of year when ozone formation is not a concern, trad itional higher VOC adhesives could still be made available. Accordingly, a two-season approach may offer an effective optimization of the competing goals of VOC reduc tion and effective roofing practice.

It is interesting to note that a similar two- season approach has already been proposed for the asphalt paving industry in the state of C onnecticut. In a public hearing May 1, 2007, a draft amendment for Subsection (k) of S ection 22a-174-20 of the Regulations of Connecticut Agencies was reviewed at a publ ic hearing. This amendment, proposed for implementation January 1, 2009, calls for a restriction on high-VOC asphalt products during the period from May 1 through Septem ber 30 of each year, w ith no restriction on these products during the remainder of the y ear. The amendment also contains specific requirements regarding the record-keepi ng necessary to assure the effective implementation of such a two-season stra tegy. Specifically, the draft amendment for asphalt paving requires that all manufacturer s, sellers, and cont ractors using asphalt paving materials to maintain and make availa ble records of test, formulation, and usage data, and any other information necessary to determine compliance with the amendment for a period of five years. In addition, the proposed amendment includes a procedure to be followed by members of the paving i ndustry in the event an exception to the amendment is required due to special circum stances, such as extreme cold conditions.

Although the two-season proposal for asphalt paving may serve as an example for a similar approach for commercial roofing, ther e are several differences between the two industries that may require minor modificati on of the proposed asphalt paving rule to adopt it to the roofing industry. The first di fference involves the relative maturity of lowVOC technology for paving materials as compared to roofing materials. In the same public hearing mentioned previ ously, the hearing officer st ated that the technology of low-VOC asphalt was well-developed and th at the industry was experienced with application differences:

“Emulsified asphalts (Ed: Low-VOC technol ogy) have been proven to perform at least as well as cutback asphalts (Ed: High-VOC technology) for all purposes during the ozone season. We recognize th at during the 1980s there were problems with emulsified asphalts. Since that time there have been improvements in the technology and most applicators have become comfortable with the differences in application between cutback and emulsifi ed asphalt. Additionally, asphalts that comply with this amendment have been in use and demonstrated to be

22successful.” (Connecticut DEP Hearing Report, Comment / Response No. 5, May 1, 2007)

Comparing the experience of the paving and roofing industries in regard to low-VOC technology, the asphalt paving industry may be mu ch better prepared to adapt to the seasonal change to low-VOC products. Low- VOC asphalt products have been in use for over 20 years throughout the United States , while low-VOC bonding adhesives for roofing have only been in service – and on a very limited basis only in California – for less than 10 years. Comparing training and e xperience differences, it is important to reiterate(as previously menti oned in this report) that less than 1000 gallons of low-VOC bonding adhesive are shipped annually to Maryland and that Maryland roofing

contractors have conducted litt le or no training with these adhesives. Accordingly, it would appear that roofing contractors ar e much less prepared than their paving counterparts to move quickly to low-VOC alternatives.

236. RECOMMENDATIONS

A. Use the Proposed Connecticut Asphalt Paving Rule as a Model for Commercial Roofing in the Northeast.

The proposed Connecticut asphalt paving amen dment, calling for the use of low-VOC products during the ozone season months of May through September, provides a reasonable basis for regulation of bonding a dhesives within the commercial roofing industry. In order to align the requirements for the commerci al roofing industry with the proposed rule for the paving industry, the OT C Model Rule for Adhesives and Sealants should be revised so that the 250 g/l ma ximum for “Single-Ply Roof Membrane Installation/Repair” is requi red only during the ozone s eason months of May through September.

B. Provide a Transitional Period for Roofing Contractors to Adapt to Low-VOC

Adhesives.

Because low temperature extremes at the be ginning and the end of the Northeast ozone season may frequently fall below the optimal operating range for low-VOC roof bonding adhesives, and because the commercial roofing industry in Maryland has yet to implement an extensive education and trai ning program for its 20,000 workers, it would be reasonable to further provide a transitiona l period that would temporarily allow the use of high-VOC adhesives during th e critical months at the be ginning and end of the ozone season. This approach would allow commercial roofing contractors to first train their crews during the optimal months of the ozone season, and then extend this experience into the less optimal months. Specifically, it is recommended that the 250 g / l maximum for “Single-Ply Roof Membrane Installation/Repair” be phased according to the following schedule:

Year: 250 g / l Required During:

2009 July through August 2010 June through September 2011 May through September

C. Develop a Reliable and Effective Industry-Sponsored Program to Assure Compliance with a Seasonal Approach

The manufacturer members of the EPDM R oofing Association are responsible for the shipment of almost all rubber roofing memb ranes and over 90% of all rubber roofing bonding adhesives in the Northeast United St ates and Maryland. Given the broad

involvement of the members of this trade a ssociation in the sale and delivery of rubber roofing adhesives, it would be reasonable to call upon them to act through their trade association to provide a reliabl e and effective program to assure that high-VOC adhesives

24are not available or used dur ing the Northeast ozone season. Elements of this program

should include:

1. A moratorium on shipments of high- VOC bonding adhesives into Maryland during the months of May through September.

2. A maximum limitation on shipments of high-VOC bonding adhesives into Maryland during the months of March a nd April to reduce the potential for stockpiling prior to the star t of the ozone season. This limitation could be based on historical shipment records along with a reasonable percen tage increase for market growth. In the event that a very large roofing project requires an unusual quantity of adhesive during this pe riod, an exception program could be established to assure and verify that the adhesives are intended for specific identified projects scheduled to be comp leted prior to the beginning of the ozone

season.

3. A reporting program to verify that all customer stocks of high-VOC adhesives have been used prior to the beginning of the ozone season, or that any remaining stocks are safely stored until the end of the ozone season or returned to the manufacturer for disposal or re-shipmen t to areas of the country where high-VOC adhesives are permitted during the summer.

4. A reporting program to provide the Maryland DEP with annual shipment information and VOC content of all rubber roofing adhesi ves shipped into Maryland.

5. A requirement that all manufacturers a nd marketers of rubber roofing systems participate in the industry program in or der to be eligible to ship high-VOC adhesives into Maryland, al ong with a requirement that the industry program be

available to all manufacturers and marketer s of rubber roofing systems regardless of membership in the in dustry trade association.

2526 TEGNOS Research, Inc. was founded in 2007 by Dr . James L. Hoff to serve the building industry by "Advancing Understanding of the Building Envelope"TM To accomplish this mission, TEGNOS provides professional services to trade and tec hnical associations within the building industry, with an em phasis on research, education and advocacy.

Additional information about TEGNOS can be found at http://www.tegnos.org . Dr. Hoff currently serves as the Research Director of the Center for Environmental Innovation in Roofing in Washington, DC, and is a boa rd member of the RCI Foundation and the

Performance Council for Constr ucted Roofing Systems.