2. Metal Roofing Systems has manufacturing facilities located in
Stanley, North Carolina and Myrtle Beach, South Carolina and
sales office in Kingsport, TN.
Metal Roofing Systems manufactures a variety of panel systems
available in more than 30 in-stock colors. From System 1000,
1500, 2000, and 2500 options to multi-rib and tee panel systems,
roofers and architects can choose from a wide variety in addition
to trim, roofing details, gutter, and distribution materials.
3. Metal Roofing Systems is a Registered Provider with The American
Institute of Architects Continuing Education Systems. Credits earned on
completion of this program will be reported to CES Records for AIA
members. Certificates of Completion for non-AIA members available on
request.
This program is registered with the AIA/CES for continuing professional
education. As such, it does not include content that may be deemed or
construed to be an approval or endorsement by the AIA of any material of
construction or any method or manner of handling, using, distributing, or
dealing in any material or product. Questions related to specific
materials, methods, and services will be addressed at the conclusion of this
presentation.
5. Learning Objectives: at the end of this program,
participants will be able to understand the following:
1. The history and applications of metal roofing systems
2. The attributes and performance of metal roofing
3. Sustainability and life cycle cost of metal roofing
4. How to design with and specify metal roofing
systems
5. Types of warranties and how to maintain metal roofs
6.
7. 970 B.C., the temple in Jerusalem had a copper
roof
Europeans were masters in the use of metal
roofs to protect buildings
◦ famous structures include the Pantheon in Rome (2nd
Century A.D.) and Notre Dame Cathedral (12th Century
A.D.)
Metal roofs were valued for several reasons:
◦ Strong enough to resist earthquakes & the strong winds
of tropical hurricanes
◦ Visually appealing
◦ When coupled with Dutch-style peaked roof and drainage
system, the metal would purify water to be stored for
household use
◦ Fire-resistant
8. Became popular in the Virgin
Islands in the 1900’s
Robert Merwin & Co., a St. Croix
Island based business, was
founded in 1892 to import
corrugated metal for buildings
Product became more widely
available and less expensive which
increased the use and established
metal roofing as a practical and
versatile alternative to clay times
9. Today’s metal roofing industry
continues to grow with new
technologies and automated
manufacturing
Latest techniques include automated
roll-forming, double folders, coatings,
sealants and fastening systems have
dramatically lowered cost and
increased versatility
10. Architects specify and use metal roofs on every type of
structure, providing owners with an aesthetic pleasing
design and unique long term benefits.
11. Types of Construction
Single Family Residential
Multi Family Residential
Office Buildings
Industrial
Institutional
Agricultural
12. Primary Roof Body
Accents (valleys, gutter downspouts…copper)
Patio Structures, covered porches, etc.
20. 1. R-value
2. High heat/solar reflectance
3. Can meet energy star requirements
21. One of the inherent benefits of metal roofing
systems is that they are resistant to fire
22. Fire rated test through Factory Mutual (FM) &
Underwriters Laboratories Inc. (UL)
Review the fire ratings in three critical areas:
◦ Roof deck
◦ Roof insulation
◦ Roof covering
23. Classifications
Class A (best)
◦ Highest rating, offering the highest
resistance to fire
◦ Typically concrete or clay roof tiles,
fiberglass asphalt composition shingles
and metal roofs
Class B
Class C
Unrated (worst)
◦ Worst ratings, generally untreated wood
shake roof
24. Evaluates the following:
1. Flame penetration through the roof covering into
the attic space,
2. Flames spread over the surface of the roof covering
3. The propensity for the roof covering to become
dislodged and generate embers.
28. Recyclable
Energy Efficient
Helps to Reduce Urban Heat Island Effect
Installs over Existing Roof Systems
Low Maintenance / Long Life
29. On average about three times the
cost of conventional asphalts roofs
The difference in cost is primarily
attributed to material cost and
installation process
Installation typically takes two to
three times long than a
conventional roof
Image
30. Will outlast cedar shakes and tile
roofs
Provide measurable energy
savings
Increase the value of the
property
Lower maintenance
Higher performance
Overall lower life cycle cost
31. Higher initial cost, lower life
cycle cost
Metal roofs have a
significantly longer expected
service life than either
asphalt or single-ply roofs
Metal roofs can expect to
last 15 to 20 years longer
than asphalt and single-ply
roofs
32.
33. ASTM E917, standard practice for measuring lifecycle
cost of buildings and building systems, is a uniform
procedure for estimating lifecycle cost for all types of
roofing systems, including metal roofing
34.
35. 1. How important are aesthetics
2. How unusual is the buildings
geometry
3. How long does the owner plan to
keep the building
4. How important is “SUSTAINABILITY” to the building’s
owner
Main considerations in determining to design
with a metal roofing system:
36. 1. Buildings require a lot of
penetrations
2. Applications with highly
corrosive effluents
3. Owner looking for the least expensive roofing system
with minimum performance
Main considerations in determining not to design with
a metal roofing system:
37. Specifiers today have a wide array of roofing options
to consider
Roofing criteria and options include:
◦ Aesthetics
◦ Performance
◦ Longevity
◦ Cost
◦ Maintenance
◦ Sustainability
◦ Structural
38. Areas of differentiation include:
Quality of design
Type of substrate
Type of coating
The manufacturing
process
39. Looking to reduce up-front cost for
short-term savings will ultimately
lead to an overall higher cost and
potential liability
Learning to evaluate and analyze
the bottom-line benefits of roofing
longevity is critical to specifying the
appropriate metal roofing solution
The performance-to-cost ratio will
vary with every roof specified and
can only be identified through a
comprehensive review of critical
design factors
40. Samples of the product
Test reports
Company brochure
Case histories
Project references
Warranty documents
Master Format specifications
41. International Code Council (ICC)
◦ International Building Code (IBC –
commercial)
◦ International Residential Code (IRC –
residential)
Local codes always takes
precedence (must be stricter)
More than 40,000 building codes
across the U.S.
42. IBC Code chapters relevant to metal
roofing:
Chapter 15, “Roof Assemblies and
Rooftop Structures,” which provides
minimum requirements for metal
roofs
Chapter 16, “Structural Design,”
which provides structural
requirements for different aspects
of construction, including but limited
to roofing
43. ASCE7 – minimum design loads for buildings and other
structures provides guidelines for each of three roofing
zones:
Zone 1 represents the central portion of the roof
Zone 2 represents the perimeter or outside edges of a
roof, where forces are more severe
Zone 3 represents the roof corners where wind forces
are at the most severe
44.
45. First and Foremost
The best way to avoid quality issues in a metal roofing
product is to invest in a high-performance product that
appropriately fits your project needs.
Put another way…don’t shop warranty, shop products.
46. No Dollar Limit
Non-Pro Rated
Total System
Single Source
47. Regular Inspections are needed to
ensure any issues that may have
arisen can be corrected in a timely
fashion
Inspect immediately following
incidents of severe weather.
Pay careful attention to gaskets
around penetrations.
48. 1. Metal Roofs have a Proven History
2. Metal Roofs provide excellent Performance even in Extreme
Conditions
3. Metal Roofs are both a SUSTAINABLE as well as a
RESPONSIBLE design choice for both Owners and the
Environment
4. Metal Roofs provide a great degree of Design Versatility
5. Metal Roofs carry Warranties that provide owners with
“Peace of Mind”
57. Thank You
This concludes The American Institute of Architects
Continuing Education Systems Program
Editor's Notes
The history of metal roofing stretches back to 970 B.C., when the temple in Jerusalem was outfitted with a copper roof. This particular style of roof developed an island identity much later when it became popular in the Virgin Islands.Metal roofs were valued for several reasons. They were strong enough to resist earthquakes and the strong winds of tropical hurricanes, while presenting a visually satisfying appearance. When coupled with the Dutch-style peaked roof and a decent drainage system, the metal would purify water which could be stored in a container for household use. The metal had the added benefit of being fire-resistant.The Europeans were masters in the use of metal roofs to protect buildings, including such famous architectural achievements as the Pantheon in Rome (2nd century A.D.) and Notre Dame Cathedral (12th century A.D.).
Robert L. Merwin & Co., a St. Croix Island based business, was founded in 1892 to import corrugated metal for buildings. They made the product cheaper and much more widely available, which served to increase its use and establish metal roofing as a much more practical and versatile alternative to clay tiles. Popularity for metal as a roofing material has continued to rise rapidly.The introduction of steel at the turn of the twentieth century, as well as a plethora of advances in the automated manufacturing of metal for construction has industry statistics projecting that the implementation of metal roofing will triple within the next five years. The latest techniques, including automated roll-forming, coatings, sealants, and fastening systems, have dramatically lowered the cost of steel roofing and only increased its versatility as the variety of colors, textures and styles has multiplied.
Robert L. Merwin & Co., a St. Croix Island based business, was founded in 1892 to import corrugated metal for buildings. They made the product cheaper and much more widely available, which served to increase its use and establish metal roofing as a much more practical and versatile alternative to clay tiles. Popularity for metal as a roofing material has continued to rise rapidly.The introduction of steel at the turn of the twentieth century, as well as a plethora of advances in the automated manufacturing of metal for construction has industry statistics projecting that the implementation of metal roofing will triple within the next five years. The latest techniques, including automated roll-forming, coatings, sealants, and fastening systems, have dramatically lowered the cost of steel roofing and only increased its versatility as the variety of colors, textures and styles has multiplied.
Robert L. Merwin & Co., a St. Croix Island based business, was founded in 1892 to import corrugated metal for buildings. They made the product cheaper and much more widely available, which served to increase its use and establish metal roofing as a much more practical and versatile alternative to clay tiles. Popularity for metal as a roofing material has continued to rise rapidly.The introduction of steel at the turn of the twentieth century, as well as a plethora of advances in the automated manufacturing of metal for construction has industry statistics projecting that the implementation of metal roofing will triple within the next five years. The latest techniques, including automated roll-forming, coatings, sealants, and fastening systems, have dramatically lowered the cost of steel roofing and only increased its versatility as the variety of colors, textures and styles has multiplied.
LightningContrary to popular belief, a metal roof will absolutely not increase the likelihood of lightning striking your home. However, if your home were hit by lightning, your metal roof would disperse the energy safely throughout the structure. Since metal roofing isn’t combustible or flammable, it’s a low risk and desirable roofing option where severe weather is concerned, especially for lightning.NoiseThough it may surprise you, metal roofing is often quieter than an asphalt shingle roof. When installed with solid sheathing, a metal roof on your home will actually silence noise from rain, hail and bad weather, many times much better than other roofing materials.RustToday’s metal roofing systems are built to last. Steel metal roofing has a “metallic coating” made of either zinc or a combination of zinc and aluminum. This metallic coating prevents rust from forming and is bonded to the steel at the point of production. Resin based coatings or “finishes” are then applied over the metallic coating to provide the long-lasting color that all owners desire.DentsIn most cases, a metal roof can withstand decades of abuse from extreme weather like hail, high winds, and heavy snow. A typical hail storm will not dent a metal roof. Today’s systems also have a 120-mph wind rating (equal to an F2 tornado), meaning your metal roof is also safe from wind gusts that can accompany hail storms.DurabilityComparatively speaking, metal roofs will last 2-3 times longer than traditional asphalts, and membrane roof systems.
less than 1/3rd the weight of asphalt and 1/10th the weight of concreteMetal roofing is available in a wide array of designs, finishes, and colors, making it ideal for the most discriminating homeowner. Whether you desire a contemporary, traditional, or old-fashioned look, you can find a metal roof that will bring out the best in your home. Check out our photo gallery or virtual roofer sections to take a look at some different styles and colors. The look of just about every house can be enhanced with the selection of the right color and design.
: less than 1/3rd the weight of asphalt and 1/10th the weight of concrete
Metal roofs are one of the most durable and weather resistant roofing materials on the market today and have the highest UL ratings for fire, wind, and impact resistant compared to other roofing materials. In most areas, metal roofs can be expected to last three or more times longer than a comparable asphalt shingle roof. In areas with extreme heat, wind, humidity, or temperature extremes, the long lasting advantage of metal roofing can be even greater.
Americans spend about $40 billion annually to air condition buildings – which equates to about one sixth of all electricity generated in this country. Studies conducted by the Cool Metal Roofing Coalition and Oak Ridge National Laboratory have shown that metal roofing with Energy Star certified high reflectance paint systems can save you up to 40% on cooling costs when compared to typical asphalt shingles.Your typical dark asphalt shingle absorbs most of the solar radiation that hits it, consequently making your attic a very hot place during the summer months. On the contrary, Energy Star certified metal roofing works by reflecting a high percentage of the sun’s energy back into the atmosphere, lowering attic temperatures and subsequent cooling loads.Metal Roofing offers several colors that are Energy Star certified. In order to meet Energy Star criteria, the roof has to have a total solar reflectance of at least 25%, which means that the roof reflects 25% of the sun’s energy. In general, lighter colors have better reflectivity, with colors such as white having a reflectivity that exceeds 60%. Furthermore, Energy Star certified roofs have to maintain a reflectance of at least 15% after three years of real-world exposure testing. The higher the reflectance, the more money you can potentially saveToday's energy costs have made R-value a "hot" topic for discussion. Before commencing our discussion, it may be useful to note: the function of a roof is to protect the insulation and everything else under it from water penetration. No roof, not even one constructed with the most sophisticated green technologies, will ever provide as much insulation value to a building as does the insulation itself.Insulation is added to the building envelope in order to maintain a desired temperature within the building at a lower cost. Typically, the more insulation that is present between the interior of a building and its exterior, the greater the temperature difference, regardless of whether the outside temperature is hot or cold. The critical measurement for determining the effectiveness of a roof’s insulation is R-value, which measures how well a particular material resists the transfer of heat.Keep in mind that wet insulation is typically considered to have an R-value of zero; once a roof develops leaks that penetrate the insulation, the owner's R-value investment is virtually lost.The insulation materials used with metal roofing are identical to those used with traditional roofs, and the selection process is much the same. The most common insulation materials used today are polyisocyanurate (commonly referred to as polyiso), perlite, expanded polystyrene, and extruded polystyrene, among others.Although R-value is the primary consideration, density is also of concern. As a general rule, a minimum density of 1-1/2 pounds of insulation per cubic foot is required for all types of roofing.However, specific R-values are mandated by the applicable building code. Keep in mind that energy-saving is an area in which local jurisdictions may prescribe a more stringent standard than that provided in the unified code.As a point of reference for commercial buildings more than three stories high, American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings, provides the means to measure energy costs, with temperature tables based on the climates of particular large cities.It is interesting to note that insulation is also a critical component in ensuring the waterproofing of a metal roof system, in that its ability to insulate the building against cooling is critical for preventing condensation. If you specify your insulation according to the mandated building code, and install a vapor retarder or appropriate ventilation, condensation will not be any more of a concern for a metal roof than it is for any other type of roofing. (See 8 below for a more detailed discussion of this topic.)Another common misconception is that the heat-conductive nature of metals will somehow adversely impact the insulation's ability to provide R-value protection. This is untrue. Metal roofs do not require more insulation than any other type of roofing to achieve the same level of effectiveness from a given type and amount of insulation.Although there are many things that can retroactively contribute to the R-value of an existing roof, nothing contributes more greatly to energy efficiency than insulation. Specifying the highest level of insulation is your client's best protection against the rising costs of energy.
Fire ratings for roofs are classified as either Class A, Class B, Class C or are unrated if a roof covering cannot meet the requirements for any of these classifications. Class A is the highest rating, offering the highest resistance to fire, and unrated is the worst. Examples of a Class A roof covering include concrete or clay roof tiles, fiberglass asphalt composition shingles and metal roofs. An example of an unrated covering is an untreated wood shake roof. If wood shakes and shingles are impregnated with fire retardant chemicals, they meet the requirements for a Class B fire rating and can meet a Class A rating if additional materials are included in the roof assemblies.A standard fire test is used to determine the fire rating of a roof covering. This test evaluates the following performance criteria: 1) flame penetration through the roof covering into the attic space, 2) flame spread over the surface of the roof covering, and 3) the propensity for the roof covering to become dislodged and generate embers. Some roof coverings rely on an underlying material, or special installation techniques, to improve their fire rating. Fire ratings for roof coverings that require an additional material are typically referred to as a "by assembly," as opposed to a "stand-alone," fire rating. If the roofing manufacturer requires that the fire rating be obtained,the installation instructions and additional material must be included in this test. Examples of a by assembly fire rating include fire-retardant treated wooden shakes and aluminum roof coverings. An exterior fire-retardant treated shake roof has a stand-alone Class B rating; but by including a particular underlying material it can meet the requirements for a Class A roof. Common underlying materials include a Type 72 roll roofing material -- also known as 72-pound felt or 72-pound capsheet material -- and a panelized gypsum product called DensDeck. Another example of a by assembly Class A roof covering includes an aluminum (metal) roof. Even though aluminum is considered a non-combustible material because of its relatively low melting point, it needs the additional underlying material to achieve the Class A fire rating.fire resistant metal roofing is inherently non-combustible, making it a great choice for areas where there is a risk for wildfires. Most house fires in these areas are caused when hot embers, or flying brands, fall on the roof and ignite the roofing material. Burning branches, leaves, and other debris are carried by heated air and wind and can threaten houses a considerable distance from the actual fire. A fire resistant roof covering adds an enormous amount of fire protection to your building structure and has been proven to help save homes in areas ravaged by fire.fire resistant metal roofing carries a Class A fire resistant rating which is the highest rating given in accordance to the UL 790 standard test methods for fire resistant tests of roof coverings. The UL 790 test covers the fire resistance performance of roof coverings exposed to simulated fire sources originating from outside a building on which the roof covering is installed. Roof coverings are rated as Class A, B, or C as defined below:Class A – Roof coverings are effective against severe fire test exposures. Under such fire exposures, roof coverings of this class afford a high degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Class B – Roof coverings are effective against moderate fire test exposures. Under such fire exposures, roof coverings of this class afford a moderate degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Class C – Roof coverings are effective against light fire test exposures. Under such fire exposures, roof coverings of this class afford a light degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Because of the proven benefits of fire resistant roofing materials such as metal, some towns have established building codes restricting the use of combustible roofing materials such as wood shakes and asphalt shingles. Remember to check local building codes prior to commencing your roofing project.
Fire ratings for roofs are classified as either Class A, Class B, Class C or are unrated if a roof covering cannot meet the requirements for any of these classifications. Class A is the highest rating, offering the highest resistance to fire, and unrated is the worst. Examples of a Class A roof covering include concrete or clay roof tiles, fiberglass asphalt composition shingles and metal roofs. An example of an unrated covering is an untreated wood shake roof. If wood shakes and shingles are impregnated with fire retardant chemicals, they meet the requirements for a Class B fire rating and can meet a Class A rating if additional materials are included in the roof assemblies.A standard fire test is used to determine the fire rating of a roof covering. This test evaluates the following performance criteria: 1) flame penetration through the roof covering into the attic space, 2) flame spread over the surface of the roof covering, and 3) the propensity for the roof covering to become dislodged and generate embers. Some roof coverings rely on an underlying material, or special installation techniques, to improve their fire rating. Fire ratings for roof coverings that require an additional material are typically referred to as a "by assembly," as opposed to a "stand-alone," fire rating. If the roofing manufacturer requires that the fire rating be obtained,the installation instructions and additional material must be included in this test. Examples of a by assembly fire rating include fire-retardant treated wooden shakes and aluminum roof coverings. An exterior fire-retardant treated shake roof has a stand-alone Class B rating; but by including a particular underlying material it can meet the requirements for a Class A roof. Common underlying materials include a Type 72 roll roofing material -- also known as 72-pound felt or 72-pound capsheet material -- and a panelized gypsum product called DensDeck. Another example of a by assembly Class A roof covering includes an aluminum (metal) roof. Even though aluminum is considered a non-combustible material because of its relatively low melting point, it needs the additional underlying material to achieve the Class A fire rating.fire resistant metal roofing is inherently non-combustible, making it a great choice for areas where there is a risk for wildfires. Most house fires in these areas are caused when hot embers, or flying brands, fall on the roof and ignite the roofing material. Burning branches, leaves, and other debris are carried by heated air and wind and can threaten houses a considerable distance from the actual fire. A fire resistant roof covering adds an enormous amount of fire protection to your building structure and has been proven to help save homes in areas ravaged by fire.fire resistant metal roofing carries a Class A fire resistant rating which is the highest rating given in accordance to the UL 790 standard test methods for fire resistant tests of roof coverings. The UL 790 test covers the fire resistance performance of roof coverings exposed to simulated fire sources originating from outside a building on which the roof covering is installed. Roof coverings are rated as Class A, B, or C as defined below:Class A – Roof coverings are effective against severe fire test exposures. Under such fire exposures, roof coverings of this class afford a high degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Class B – Roof coverings are effective against moderate fire test exposures. Under such fire exposures, roof coverings of this class afford a moderate degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Class C – Roof coverings are effective against light fire test exposures. Under such fire exposures, roof coverings of this class afford a light degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Because of the proven benefits of fire resistant roofing materials such as metal, some towns have established building codes restricting the use of combustible roofing materials such as wood shakes and asphalt shingles. Remember to check local building codes prior to commencing your roofing project.
Fire ratings for roofs are classified as either Class A, Class B, Class C or are unrated if a roof covering cannot meet the requirements for any of these classifications. Class A is the highest rating, offering the highest resistance to fire, and unrated is the worst. Examples of a Class A roof covering include concrete or clay roof tiles, fiberglass asphalt composition shingles and metal roofs. An example of an unrated covering is an untreated wood shake roof. If wood shakes and shingles are impregnated with fire retardant chemicals, they meet the requirements for a Class B fire rating and can meet a Class A rating if additional materials are included in the roof assemblies.A standard fire test is used to determine the fire rating of a roof covering. This test evaluates the following performance criteria: 1) flame penetration through the roof covering into the attic space, 2) flame spread over the surface of the roof covering, and 3) the propensity for the roof covering to become dislodged and generate embers. Some roof coverings rely on an underlying material, or special installation techniques, to improve their fire rating. Fire ratings for roof coverings that require an additional material are typically referred to as a "by assembly," as opposed to a "stand-alone," fire rating. If the roofing manufacturer requires that the fire rating be obtained,the installation instructions and additional material must be included in this test. Examples of a by assembly fire rating include fire-retardant treated wooden shakes and aluminum roof coverings. An exterior fire-retardant treated shake roof has a stand-alone Class B rating; but by including a particular underlying material it can meet the requirements for a Class A roof. Common underlying materials include a Type 72 roll roofing material -- also known as 72-pound felt or 72-pound capsheet material -- and a panelized gypsum product called DensDeck. Another example of a by assembly Class A roof covering includes an aluminum (metal) roof. Even though aluminum is considered a non-combustible material because of its relatively low melting point, it needs the additional underlying material to achieve the Class A fire rating.fire resistant metal roofing is inherently non-combustible, making it a great choice for areas where there is a risk for wildfires. Most house fires in these areas are caused when hot embers, or flying brands, fall on the roof and ignite the roofing material. Burning branches, leaves, and other debris are carried by heated air and wind and can threaten houses a considerable distance from the actual fire. A fire resistant roof covering adds an enormous amount of fire protection to your building structure and has been proven to help save homes in areas ravaged by fire.fire resistant metal roofing carries a Class A fire resistant rating which is the highest rating given in accordance to the UL 790 standard test methods for fire resistant tests of roof coverings. The UL 790 test covers the fire resistance performance of roof coverings exposed to simulated fire sources originating from outside a building on which the roof covering is installed. Roof coverings are rated as Class A, B, or C as defined below:Class A – Roof coverings are effective against severe fire test exposures. Under such fire exposures, roof coverings of this class afford a high degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Class B – Roof coverings are effective against moderate fire test exposures. Under such fire exposures, roof coverings of this class afford a moderate degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Class C – Roof coverings are effective against light fire test exposures. Under such fire exposures, roof coverings of this class afford a light degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Because of the proven benefits of fire resistant roofing materials such as metal, some towns have established building codes restricting the use of combustible roofing materials such as wood shakes and asphalt shingles. Remember to check local building codes prior to commencing your roofing project.
Fire ratings for roofs are classified as either Class A, Class B, Class C or are unrated if a roof covering cannot meet the requirements for any of these classifications. Class A is the highest rating, offering the highest resistance to fire, and unrated is the worst. Examples of a Class A roof covering include concrete or clay roof tiles, fiberglass asphalt composition shingles and metal roofs. An example of an unrated covering is an untreated wood shake roof. If wood shakes and shingles are impregnated with fire retardant chemicals, they meet the requirements for a Class B fire rating and can meet a Class A rating if additional materials are included in the roof assemblies.A standard fire test is used to determine the fire rating of a roof covering. This test evaluates the following performance criteria: 1) flame penetration through the roof covering into the attic space, 2) flame spread over the surface of the roof covering, and 3) the propensity for the roof covering to become dislodged and generate embers. Some roof coverings rely on an underlying material, or special installation techniques, to improve their fire rating. Fire ratings for roof coverings that require an additional material are typically referred to as a "by assembly," as opposed to a "stand-alone," fire rating. If the roofing manufacturer requires that the fire rating be obtained,the installation instructions and additional material must be included in this test. Examples of a by assembly fire rating include fire-retardant treated wooden shakes and aluminum roof coverings. An exterior fire-retardant treated shake roof has a stand-alone Class B rating; but by including a particular underlying material it can meet the requirements for a Class A roof. Common underlying materials include a Type 72 roll roofing material -- also known as 72-pound felt or 72-pound capsheet material -- and a panelized gypsum product called DensDeck. Another example of a by assembly Class A roof covering includes an aluminum (metal) roof. Even though aluminum is considered a non-combustible material because of its relatively low melting point, it needs the additional underlying material to achieve the Class A fire rating.fire resistant metal roofing is inherently non-combustible, making it a great choice for areas where there is a risk for wildfires. Most house fires in these areas are caused when hot embers, or flying brands, fall on the roof and ignite the roofing material. Burning branches, leaves, and other debris are carried by heated air and wind and can threaten houses a considerable distance from the actual fire. A fire resistant roof covering adds an enormous amount of fire protection to your building structure and has been proven to help save homes in areas ravaged by fire.fire resistant metal roofing carries a Class A fire resistant rating which is the highest rating given in accordance to the UL 790 standard test methods for fire resistant tests of roof coverings. The UL 790 test covers the fire resistance performance of roof coverings exposed to simulated fire sources originating from outside a building on which the roof covering is installed. Roof coverings are rated as Class A, B, or C as defined below:Class A – Roof coverings are effective against severe fire test exposures. Under such fire exposures, roof coverings of this class afford a high degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Class B – Roof coverings are effective against moderate fire test exposures. Under such fire exposures, roof coverings of this class afford a moderate degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Class C – Roof coverings are effective against light fire test exposures. Under such fire exposures, roof coverings of this class afford a light degree of fire protection to the roof deck, do not slip from position, and are not expected to product flying brands.Because of the proven benefits of fire resistant roofing materials such as metal, some towns have established building codes restricting the use of combustible roofing materials such as wood shakes and asphalt shingles. Remember to check local building codes prior to commencing your roofing project.
Wind forces remain one of the most common factors in roof failures, inflicting considerable damage every year, even to new roof structures. Metal roofs are one of the popular low‐sloped roof assemblies. Based on their layout, they can be categorized as either composite or non‐composite assemblies. In North American practice, five main test procedures — ASTM E1592, ANSI/FM 4474, UL 580, UL 1817 and CSA A123.21‐04 — are used to determine the wind uplift performance of metal roofs. The fundamental differences between these test protocols lie in the way they represent wind effects on the performance of metal roofing systems. Of the five, CSA A 123.21‐04 is the only one that assesses the wind uplift resistance under dynamic wind load conditions. To evaluate the wind uplift performance of non‐composite and composite metal roofing assemblies, eight assemblies with two different types of panels — SNAP‐IT and MR‐24 — were tested using the CSA A123.21‐04 dynamic test protocol. Relating air intrusion characteristics of the subsurface components to panel behavior, this paper shows how composite assemblies resist wind uplift pressures better than non‐composite assemblies. The paper reveals that the greater the air intrusion resistance of the sub‐surface components in composite assemblies, the higher the suction resistance, the lesser the panel deflection, the lesser the stress on the panels and the higher the wind uplift resistance.
As previously explained, the non-continuous attachment of metal roofs makes them particularly susceptible to wind uplift concerns. Wind subjects metal roofing materials, and the quality of their installations, to their most rigorous test.The major factors relevant to a roof's ability to withstand wind-uplift pressures are:Wind speed (the greater the speed, the greater the wind-uplift pressure)Building elevation (the higher the building, the greater the wind-uplift pressure)Exposure to wind (i.e., whether or not the building is protected from wind by surrounding structures)Roof slope (the lower the slope, the greater the wind-uplift pressure, depending on the building dimensions)Building geometry/dimensions (not only the size of the roof, but the geometric complexities of its design that might break or facilitate wind flow)The complexities of analyzing and identifying probable wind-uplift forces make it impossible for building codes to limit the use of metal systems to certain geographies or generic conditions. Rather, they establish a methodology for identifying anticipated wind-uplift pressures, then stipulate that the specified roof must be capable of withstanding such pressures. The methodology used applies a general formula to the particulars of an installation, as described above.To complicate things further, the amount of wind-uplift pressure varies greatly even across the various expanses of a single roof. Common sense dictates that the perimeter of a roof, which initially breaks the wind flow, must be designed to sustain far greater pressure than the middle of the roof. Similarly, the corners of a roof, which are simultaneously exposed to pressure from different directions, must be designed to sustain even greater wind-uplift pressure.There is no such thing as a generic roof installation. No two roofs will share identical design parameters, as defined by their elevations, slopes, etc. More importantly, a single roof will require more insulation board fasteners per inch and shorter distances between clips (if standing seam) at its corners and perimeters than across its central field. As an example, depending on the wind uplift calculations for the various zones on a single building, the recommended clip spacing could range from as stringent as one clip per one square foot to one clip per ten square feet.Essentially, all a building code can do is to provide general guidelines for developing clip spacing distances appropriate to anticipated wind-uplift pressures. But it is up to the design professional to identify the probable wind-uplift pressures for each of the three zones of a roof, based upon its particular parameters.
Metal is one of the most environmentally friendly and sustainable green roofing materials you can choose for your home’s roof. Green roofing materials offer energy efficiency, recyclability, and extremely low maintenance requirements.RECYCLABLEThe type of roofing material you choose can have a big impact on the environment. For instance, asphalt roof shingles generate an astounding amount of landfill waste each year, estimated at 6.8 million tons, or 3% of all municipal solid waste. When a shingle roof wears out and needs to be replaced, the old roof shingles need to be stripped and there are no uses for the old roofing material.Conversely, metal roofs are 100% recyclable when removed from service. And better yet, metal roofs meet the definitions for both recycled content and recyclability by industry recognized green building definitions. Union’s metal roofs are constructed of a minimum 20% recycled roofing material, and many times this approaches 60%. In addition, the outstanding durability and life-span of recycled metal roofs minimizes consumption due to roof replacement and repairs. In general, recycled metal roofs last 3 to 4 times longer than asphalt roof shingles, so savings in roofing material consumption are significant.ISLAND EFFECTn many urban areas of North America, the prevalent use of energy-absorbing roofing and building materials such as asphalt shingles, concrete, and pavements can create a microclimate wherein temperatures are higher than in surrounding rural areas. These roofing materials absorb and store large amounts of solar energy during the day, causing ambient temperatures to remain unnaturally high, sometimes by as much as 12 F. This is called the urban heat island effect and these higher temperatures lead to a host of other problems, including increased energy consumption and a greater incidence of ozone and smog formation. Studies have shown that reducing ambient temperatures by as little as one half degree can reduce smog by 5%.Energy Star certified metal roofs help reduce this urban heat island effect by reflecting a high percentage of the sun’s energy back into the atmosphere, reducing heat buildup. So not only can you lower your own utility bills, you can do your part to ensure a healthy environment in your own community.INSTALLS OVER EXISTING ROOFSMetal roofs have the best strength to weight ratio of any roofing material, allowing them to be installed over existing roof systems without the need to add structural support to the roof. Union’s steel roofing panels weigh 50% to 65% less per square foot than most asphalt shingles. Installing over your existing roof eliminates landfill waste and saves labor costs for removing the old roof material.Most roof types simply weigh too much to be installed over top of one another without adding additional structural support to the roof. Roofs are designed to support a predetermined amount of weight and the addition of subsequent layers of heavy roofing materials such as asphalt shingles can cause structural damage. In these cases, removing the old shingles is usually recommended, but this creates a large amount of landfill waste. In fact, asphalt shingles make up over 3% of all municipal solid waste, or 6.8 million tons annually.Because metal roofs are so light yet so strong, they can typically be easily installed over your existing roof without the need to add structural reinforcement. The old roof materials under the metal roof simply serve as an extra layer of insulation and water protection and pose no problems to the new metal roof. Of course, each application is different, so consult your licensed roofing contractor to confirm if your roof is suitable for a roof-over installation.LOW MAINTENANCEn general, the less materials used in the construction and upkeep of your home, the less negative impact there is on the environment. In this regard, metal roofs perform remarkably well. The lifespan of a typical metal roof is 3 to 4 times that of an asphalt shingle roof. In other words, over the course of the life of your metal roof, you would have to replace a shingle roof 3 to 4 times. This results in a tremendous amount of material consumption, landfill waste, and additional waste in terms of labor, fuel consumption, and productivity.However, this still doesn’t include the maintenance savings you get with a metal roof. Generally speaking, wind and weather events damage individual shingles once every 2 to 3 years. This recurring problem does not occur with metal roofs due to their inherent wind uplift resistance. Over the life of a typical asphalt roof, you can expect to make minor repairs 5 to 7 times. In addition to the cost, each of these repair events consumes materials and fuel, not including the frustration and inconvenience suffered by the homeowner. By comparison, an average metal roof will require no repairs during the same period.Taken together, you can expect 15 to 30 more repair and replacement events with an asphalt roof over the average life of a typical metal roof. Over time, these events add up in terms of cost, waste, and inconvenience. This is why metal roofs are the fastest growing segment of the residential roofing market.
How much does metal roofing cost?In a nutshell...On average, metal roofing costs tend to be about three times the cost of conventional asphalt roofs. The difference in cost is attributed to a much higher cost of metal roofing materials, and a highly technically involved installation process that requires specialized skills, and specific training for the metal roofing system being installed. The often tedious and time-consuming installation process requires longer hours, precision and patience. On average, metal roof takes about two to three times longer to install than a conventional roof.Although, metal roofs cost more than asphalt shingle roofs, its cost is comparable to the cost of cedar shake and tile roofs. Yet, a metal roof that was installed the right way, will outlast cedar shake and tile roofs. Not only that, metal roof will provide measurable energy savings (many homeowners report 20% cooling costs savings). A freshly installed metal roof will increase the monetary value of any building, therby reducing its intial cost. In retrospect, a metal roof that costs more initially, can pay for itself overtime by increasing the value of a building, providing notable energy savings, requiring no maintainance and therby saving money, and finally by providing a reliable protection that will save money in water damage and repair costs.
How much does metal roofing cost?In a nutshell...On average, metal roofing costs tend to be about three times the cost of conventional asphalt roofs. The difference in cost is attributed to a much higher cost of metal roofing materials, and a highly technically involved installation process that requires specialized skills, and specific training for the metal roofing system being installed. The often tedious and time-consuming installation process requires longer hours, precision and patience. On average, metal roof takes about two to three times longer to install than a conventional roof.Although, metal roofs cost more than asphalt shingle roofs, its cost is comparable to the cost of cedar shake and tile roofs. Yet, a metal roof that was installed the right way, will outlast cedar shake and tile roofs. Not only that, metal roof will provide measurable energy savings (many homeowners report 20% cooling costs savings). A freshly installed metal roof will increase the monetary value of any building, thereby reducing its intial cost. In retrospect, a metal roof that costs more initially, can pay for itself overtime by increasing the value of a building, providing notable energy savings, requiring no maintenance and thereby saving money, and finally by providing a reliable protection that will save money in water damage and repair costs.
4. Lifecycle
4. Lifecycle
4. Lifecycle cost analysisLifecycle cost analysis is a worthwhile exercise when attempting to establish the value of metal systems in comparison with non-metal alternatives. ASTM International E 917, Standard Practice for Measuring Lifecycle Costs of Buildings and Building Systems, is a uniform procedure for establishing lifecycle costs for all types of roofing systems, including metal roofing.The many proprietary software tools currently available for analyzing life-cycle cost benefits are generally based on ASTM E 917. However, some of the more ambitious ones attempt to quantify more illusive cost savings. They take into consideration such factors as initial purchase price, maintenance costs, operating costs, disposal costs, and replacement costs over the life of a roof system. Other financial assumptions that must be taken into account are changing material costs, the inflation rate, and costs related to energy use. All anticipated costs over the working life of a roof are added to the initial material and installation costs, in order to arrive at a realistic total cost.Generally speaking, the longer-lived the metal solution (see introductory section of this article on the advantages of metal), the greater its life-cycle cost advantages.
a comprehensive review of several factors, including:How long will the client own the property? Since metal roof systems can significantly outlast most non-metal alternatives, property owners who intend to hold on to their buildings longer will reap the largest rewards from metal's life-cycle costing advantages.How disruptive will eventual restoration and re-roofing be to the building’s occupants? The installation of a metal roof is odor-free, cleaner, and more environmentally friendly than hot-applied systems. However, installing metal systems can present logistical concerns, especially for high-rise buildings with limited access. Although freight elevators can typically carry materials needed for non-metal systems, for metal systems, large cranes may be necessary to haul longer panels to the top of the building.What is the intrinsic value of the property under the roof? The higher the value of the property occupying a building, the easier it is for building owners to rationalize the higher initial costs of metal systems.What is the customer’s existing budget? If price were no object, we'd all be living and working under roofs of copper, zinc, or even titanium. Regardless of the desirability of long-term solutions, short-term budget realities sometimes prohibit lasting solutions. When a customer's initial budget will not accommodate the costs of a premium metal, innovative financial products such as leasing may be considered. Equally relevant is how soon additional money will become available. It may make sense to install a low-cost alternative on new construction, when budgets are strained, if seven years down the road money will become available for installing a more lasting metal roof system.How important are aesthetic considerations, given the roof’s location and the building’s function? Aesthetic versatility is probably the single biggest reason that owners opt for metal roofing. When aesthetics are a major concern, metal roofing offers added value.How likely is it that the owner will follow through on routine maintenance? Generally speaking, metal roofing requires less maintenance than non-metal systems, which may need more frequent re-coating, fresh graveling, or aggressive restoration to maintain resistance to ultraviolet (UV) radiation and weather.How frequently will the roof need to be accessed due to HVAC, rooftop photovoltaic (PV) systems, or other utilities? Although metal systems withstand foot traffic as well or better than non-metal roofs, roofs that require a lot of penetrations for HVAC or other appliances are not ideal candidates for metal roofing, as previously explained (see introductory section of this article on the advantages of metal).Engineering Concerns in Metal RoofingBy Mike Huber, PEWhen it comes to designing or specifying commercial metal roofing, knowledge is security. There are ten fundamental areas of concern with metal roofing, and no substitute for understanding the basic design considerations that apply to them. While particulars will vary according to geographical region, system profiles used, and the characteristics of each building, awareness of the principles underlying each of these concerns is a valuable tool for any design professional to have.The advantages of metalWhen determining whether metal is a viable alternative to conventional roofing materials, such as single ply or built-up asphalt roofing, here are the main considerations.How important are aesthetic considerations? Many metal systems offer significant aesthetic advantages over conventional roofing. From the richly toned natural surfaces of copper and titanium, to the hundreds of colors currently available for steel roofing, metals offer an exciting spectrum of aesthetic options. High-profile projects, office or retail complexes, hospitals and schools, are some examples of applications for which curb appeal is a primary motivator.How unusual is the building geometry? Some architectural designs can only be achieved through the curving properties of metal solutions; for example, the metal domes so popular for sports and entertainment facilities.How long does the owner intend to keep the building? Metals such as copper and titanium can be expected to last hundreds of years. Even steel roofs have an anticipated life span of 30 years, which is more than three times longer than that of many other roofing options.How committed is the building owner to sustainability? A property owner who wants to meet LEED ® performance criteria will put a premium value on metal solutions. Most metal substrates consist of material that has already been recycled, and all metal substrates are themselves recyclable when the time comes for eventual tear down or replacement. As an example, a recent survey of aluminum producers revealed that the total recycled content in flat-rolled products for the building and construction market was 80 to 85 percent.It should be noted that despite the common misconception that metal roofs are heavier roofs, the light-gauge metals used for roofing are among the lightest weight roofing materials commonly used today. In fact, only single ply systems are consistently lighter. Metal systems are appropriate not only for new construction, but for retrofitting a new roof over an existing roof, especially where roof deck designs require a lighter-weight roof covering.
Engineering Concerns in Metal RoofingBy Mike Huber, PEOn the negative side of the equation, there are some application considerations that work against the viability of a metal solution:Buildings requiring a lot of penetrations and flashings provide more opportunity for installation error. Since metal systems typically require more complex detailing, they should be avoided in such applications except where the contractor craftsmanship is impeccable and there is independent auditing of the installation process.Applications with highly corrosive effluents, such as steel and utility plants, may be better served with non-metal solutions, since metals are innately susceptible to degradation from corrosion.Marine environments (within five miles or less of a salt-laden sea) are generally not well-served by traditional steel roofs. However, some alternative metals, such as aluminum, are viable in marine environments., especially where roof deck designs require a lighter-weight roof covering.
Evaluating metal alternativesSpecifiers have never had such a wide array of aesthetic metal options, and aesthetic concerns are the driving factor when choosing one metal substrate over another. The other major factor to consider is longevity. Generally speaking, the longevity of a material increases in proportion to its cost.Steel roofs, which are almost always treated with a metallic coating to protect against oxidation and corrosion, generally can be expected to last 30 years or longer with traditional metallic coatings such as galvanized or Galvalume®1 . Today's metal roofing manufacturers sometimes offer proprietary metallic coatings for steel systems that can further extend their anticipated life span.Aluminum roofs are more corrosion-resistant than steel roofs, and can be expected to last from 50 to 100 years, depending on environmental considerations, such as weather and corrosives. Aluminum is also the lightest in weight of the readily available metal substrates, so may offer some advantages in retrofit situations. However, it is generally acknowledged that the weight differences between roof panels of varying metal substrates, with their associated claddings, is negligible.Other premium metal substrates, such as copper, stainless steel, zinc, and titanium, can be expected to last hundreds of years.
These are all areas of critical importance….while substrates and coatings are important….without a doubt the methods of manufacture should be considered with the utmost of concern.
A reasonable investigation focusing on material future matters. *****EXTREMELY IMPORTANT TO DO YOUR HOMEWORK***** prior to specifying or approving a design or manufacturer.
Building code requirementsHistorically, there have been three primary regional building codes used in the United States:Building Officials & Code Administrators (BOCA), serving the NortheastStandard Building Code Congress International (SBCCI), serving the SoutheastInternational Conference of Building Officials (ICBO), serving the WestIn recent years, the three regional U.S. building-code bodies consolidated their efforts into a single International Building Code (IBC), under the auspices of the International Code Council (ICC). Local jurisdictions are still in the process of replacing previously applicable regional codes with the new unified code, as their de facto standard of reference.However, in any construction situation, the local code always takes precedence. There are currently more than 40,000 building codes across the U.S. Although the majority of them base their codes on a standard code of reference (previously a regional code, but increasingly the IBC), when local codes deviate from their referenced standard they are always stricter. Even after the IBC has been universally adopted, as it is expected to be, architects, engineers, and specifiers will always have to take into consideration any additional mandates prescribed by local jurisdictions.Although the most current version of the unified code is IBC 2009, as of this writing most jurisdictions have not yet adopted it. To date, IBC 2006 is the norm in most areas, but IBC 2009 will eventually supplant it.In both the 2006 and 2009 versions of the IBC, the chapters relevant to metal roofing are:Chapter 15, “Roof Assemblies and Rooftop Structures,” which provides minimum requirements for metal roofsChapter 16, "Structural Design," which provides structural requirements for different aspects of construction, including but not limited to roofing, stainless steel, zinc, and titanium, can be expected to last hundreds of years.
Building code requirementsHistorically, there have been three primary regional building codes used in the United States:Building Officials & Code Administrators (BOCA), serving the NortheastStandard Building Code Congress International (SBCCI), serving the SoutheastInternational Conference of Building Officials (ICBO), serving the WestIn recent years, the three regional U.S. building-code bodies consolidated their efforts into a single International Building Code (IBC), under the auspices of the International Code Council (ICC). Local jurisdictions are still in the process of replacing previously applicable regional codes with the new unified code, as their de facto standard of reference.However, in any construction situation, the local code always takes precedence. There are currently more than 40,000 building codes across the U.S. Although the majority of them base their codes on a standard code of reference (previously a regional code, but increasingly the IBC), when local codes deviate from their referenced standard they are always stricter. Even after the IBC has been universally adopted, as it is expected to be, architects, engineers, and specifiers will always have to take into consideration any additional mandates prescribed by local jurisdictions.Although the most current version of the unified code is IBC 2009, as of this writing most jurisdictions have not yet adopted it. To date, IBC 2006 is the norm in most areas, but IBC 2009 will eventually supplant it.In both the 2006 and 2009 versions of the IBC, the chapters relevant to metal roofing are:Chapter 15, “Roof Assemblies and Rooftop Structures,” which provides minimum requirements for metal roofsChapter 16, "Structural Design," which provides structural requirements for different aspects of construction, including but not limited to roofing, stainless steel, zinc, and titanium, can be expected to last hundreds of years.
ASCE 7, Minimum Design Loads for Buildings and Other Structures provides guidelines for each of three roofing zones:Zone 1 represents the central portion of the roof. Since wind forces are somewhat dissipated by the time they reach the center of a roof surface, having already broken against the building's corners and perimeters, the clip distance requirements for Zone 1 are the least stringent.Zone 2 represents the perimeter or outside edges of a roof, where wind forces are more severe since it is the edges of the roof that meet the full force of the wind. The clip distances required for the roof edge to sustain anticipated wind-uplift pressures are always more stringent than the distances required for the central surface area.Zone 3 represents the roof corners where wind forces are at their most severe. Again, severity is a relative measurement and does not relate to any specific minimum or maximum pressure. Simply stated, any roof corner must be capable of withstanding more wind-uplift pressure than its central field or perimeters since roof corners are simultaneously subjected to wind-uplift pressure from two sides.The American Society of Civil Engineering (ASCE) has developed a calculation, as part of ASCE 7, Minimum Design Loads for Buildings and Other Structures, for determining the wind forces in the three roof zones. The calculation first takes into account all of the design parameters that collectively predict the probable wind-uplift pressures for a particular roof. It then provides a methodology for calculating the relative force exerted on each of the three defined zones when subjected to the anticipated wind-uplift pressure.Due to the complexity of the ASCE-7 methodology, it is usually a structural engineer who will evaluate the parameters of a roof design, identify probable wind uplift, and provide A/Es and specifiers with appropriate clip spacing distances for each of three zones.
Metal Roofing Warranties: What You Need to KnowWhile metal roofing is known for its strength, durability and lasting beauty, some metal roofing products do perform better than others. Contributing factors include quality of design, substrates, coatings and manufacturers' fabrication processes. Proper metal panel selection begins with the ultimate end-use for the panels. For example, residential and high profile projects often call for an entirely different level of panel quality than a shade and shelter application. The information below describes what characteristics and manufacturing processes to look for when selecting a metal panel.Warranties are also a consideration when selecting a metal panel. Consumers often associate warranty with dependability and performance. This is not necessarily the case. Just because a warranty has an extended time frame (45 years or even a “lifetime”), it does not necessarily mean that the warranty is better or that the product offers better performance. We encourage you to fully read and understand your supplier’s warranties.n the long run, the best way to avoid a painful relationship with a metal product is to invest in a high-performance component that appropriately fits your application. In other words, don't shop for a warranty - shop for a product from a manufacturer that has a stake in that product's success. At McElroy Metal, we engineer high-performance, application-specific metal components with warranties that fit the bill.
