Metal roofing is gaining popularity, and for good reason. Its durable, energy-efficient, and can give a home a sleek, modern look. But a quality metal roof requires expert installation. Cutting corners can lead to leaks, premature wear, and even structural damage. So, what are the best practices roofers should follow for a successful metal roof installation?
First and foremost, proper planning is crucial. This involves accurate measurements of the roof, factoring in overhangs and valleys. Choosing the right type of metal roofing for the climate is also essential. For example, in areas prone to hail, a thicker gauge metal is recommended. Roofers should also consider the roof pitch and local building codes when selecting materials and fasteners.
Next comes surface preparation. The existing roof needs to be thoroughly inspected for damage. Any rotted wood or damaged sheathing must be replaced before the metal roof is installed. Proper underlayment is key, acting as a barrier against moisture and providing a smooth surface for the metal panels. This underlayment should be specifically designed for metal roofing.
The actual installation process requires precision and attention to detail. Panels should be carefully aligned and secured with the correct type of fasteners, spaced appropriately to allow for thermal expansion and contraction. Overdriving or underdriving screws can compromise the integrity of the roof and lead to leaks. Sealant should be used at all penetrations, such as chimneys and vents, to prevent water intrusion.
Proper ventilation is often overlooked but is vital for a long-lasting metal roof. Adequate airflow helps regulate temperature and prevents moisture buildup, which can lead to corrosion and rot. Ridge vents and soffit vents work together to create a balanced ventilation system.
Finally, cleanup is essential. All debris, including metal shavings and old roofing materials, should be removed from the site. This not only improves the aesthetics but also prevents potential hazards.
By adhering to these best practices, roofers can ensure a durable, weather-resistant, and aesthetically pleasing metal roof that will protect the home for decades to come. A well-installed metal roof is an investment that pays off in the long run, providing peace of mind and enhancing the value of the property.
Metal roofs are known for their longevity and durability, but even these tough titans can face issues. For roofers, understanding common metal roofing problems and their solutions is key to providing quality service and ensuring customer satisfaction. Lets explore some of the typical culprits.
One frequent problem is leaks, often caused by fastener failures. Over time, screws can back out or the rubber washers can deteriorate, creating openings for water intrusion. The fix involves replacing faulty fasteners with high-quality, corrosion-resistant screws and ensuring proper sealant application. Improper installation is another major contributor to leaks. Lap joints and seams that arent sealed correctly or panels that arent secured tightly can create vulnerabilities. Addressing these issues might require resealing seams, adjusting panels, or even partial roof replacement in severe cases.
Another common issue is oil canning, the wavy or distorted appearance that can occur in flat metal panels. While not always a leak risk, it can be an aesthetic concern for homeowners. Minimizing oil canning starts with proper installation techniques, including correct panel attachment and spacing. Choosing thicker gauge metal can also help reduce the likelihood of oil canning.
Rust is a familiar foe, especially in coastal environments or areas with high humidity. While most modern metal roofs have protective coatings, these can be scratched or damaged, leading to corrosion. Addressing rust involves removing the affected area, treating it with a rust inhibitor, and applying a sealant or touch-up paint. In more severe cases, panel replacement might be necessary.
Scratches and dents can occur from falling debris, hail, or even foot traffic. Minor scratches can often be addressed with touch-up paint. Dents, however, can be more challenging. Depending on the severity and location, they might require patching or panel replacement.
Finally, expansion and contraction due to temperature fluctuations can cause fastener holes to become enlarged or create stress on seams. Using fasteners specifically designed for metal roofing, with robust washers and sealant, can help mitigate this issue. Properly installed expansion joints also allow the roof to move without causing damage.
By understanding these common metal roofing problems and their respective solutions, roofers can provide effective repairs, extend the life of the roof, and ensure their customers have a secure and aesthetically pleasing roof for years to come. Regular inspections and preventative maintenance are also crucial for catching small problems before they escalate into major headaches.
Working on a roof, especially a metal one, is inherently dangerous. For roofers, installing metal roofs demands a heightened awareness of safety considerations, going beyond the usual precautions for any roofing job. Metal roofs present unique challenges, primarily due to their slippery surfaces, sharp edges, and the potential for amplified heat and electrical conductivity.
One crucial aspect is fall protection. Harness systems, guardrails, and safety nets are non-negotiable. The slick nature of metal, especially when wet, icy, or coated with dust, increases the risk of slips. Roofers must wear shoes with excellent grip and tread carefully. Secure footing is paramount.
Sharp edges and corners on metal panels pose a laceration hazard. Heavy-duty gloves, long sleeves, and eye protection are essential. Handling panels requires proper lifting techniques to avoid back injuries and ensure the material is secured against wind gusts before fastening.
The suns reflection off metal roofs can create intensely hot surfaces, leading to burns and heat exhaustion. Working during cooler parts of the day, staying hydrated, and wearing light-colored, breathable clothing are necessary precautions. Sunscreen and regular breaks in shaded areas are also highly recommended.
Metals conductivity makes electrical hazards a serious concern. Roofers must be aware of power lines and maintain a safe distance. Using non-conductive tools and equipment is critical. Before starting any work, de-energizing nearby power lines should be considered and coordinated with the utility company if necessary.
Weather conditions play a significant role in roofer safety. High winds can make working at heights extremely dangerous, and rain increases the slipperiness of metal. Lightning is a major threat. Work should be stopped immediately and safe shelter sought if thunderstorms are approaching.
Finally, proper training and communication are vital. Roofers should be thoroughly trained in metal roof installation techniques and safety procedures. A designated safety monitor on the ground can provide an extra layer of protection, observing for potential hazards and communicating with the team on the roof. Regular safety meetings and toolbox talks reinforce best practices and address specific site concerns. By prioritizing safety and adhering to these precautions, roofers can minimize risks and ensure a safe and successful metal roof installation.
Estimating and pricing metal roofing jobs is a crucial skill for any roofer looking to succeed in this specialized field. Its more complex than simply measuring the roof and slapping on a price per square foot. Getting it right means the difference between making a healthy profit and losing your shirt. Heres a glimpse into the process:
First, accurate measurements are paramount. While some roofers rely on satellite imagery for initial estimates, nothing beats climbing up there and getting your own measurements. You need to account for every nook, cranny, valley, hip, and ridge. Remember, metal roofing often comes in panels of specific lengths, so precise measurements minimize waste and ensure you order the correct amount of material.
Next, material cost is a major factor. Metal roofing comes in a variety of materials, from affordable steel to pricier copper and zinc. The gauge (thickness) of the metal also impacts cost, as does the finish (painted, galvanized, etc.). Dont forget to factor in the cost of flashing, fasteners, sealants, and underlayment. Supply chain issues and market fluctuations can also impact pricing, so staying up-to-date is essential.
Labor costs are equally important. Installing metal roofing requires specialized skills and can be more time-consuming than asphalt shingles. Consider the complexity of the roof design, the pitch (steepness), and accessibility. A complex roof with multiple valleys and dormers will require more labor than a simple gable roof. Also, factor in the time for removing the existing roof, if necessary.
Beyond materials and labor, other expenses need to be considered. These include permits, disposal fees for old roofing materials, equipment rentals (like scaffolding), insurance, and your desired profit margin. Dont underestimate these costs; they can quickly add up.
Finally, presenting a professional and detailed estimate to the homeowner is key to winning the job. Clearly outline all the costs involved, including a breakdown of materials, labor, and other expenses. Explain your process and timeline, and be prepared to answer any questions they may have. A well-presented estimate builds trust and shows youre a serious professional.
Estimating and pricing metal roofing jobs is a balancing act. You need to be competitive while ensuring you cover all your costs and make a fair profit. By taking a meticulous approach and staying informed about market conditions, you can set yourself up for success in the metal roofing business.
A roofer, roof mechanic, or roofing contractor is a tradesman who specializes in roof construction. Roofers replace, repair, and install the roofs of buildings, using a variety of materials, including shingles, single-ply, bitumen, and metal. Roofing work includes the hoisting, storage, application, and removal of roofing materials and equipment, including related insulation, sheet metal, vapor barrier work, and green technologies rooftop jobs such as vegetative roofs, rainwater harvesting systems, and photovoltaic products, such as solar shingles and solar tiles.[1][2]
Roofing work can be physically demanding because it may involve heavy lifting, climbing, bending, and kneeling, often in extreme weather conditions.[1] Roofers are also vulnerable to falls from heights due to working at elevated heights. Various protective measures are required in many countries. In the United States these requirement are established by the Occupational Safety and Health Administration (OSHA) to address this concern.[3][4][5] Several resources from occupational health agencies are available on implementing the required and other recommended interventions.[6][7][8]
According to data from the U.S. Bureau of Labor Statistics (BLS), as of May 2022[update], there were 129,300 individuals working as roofers in the construction industry. Among that population, a majority of roofers (93%; 119,800) were contractors for Foundation, Structure, and Building Exterior projects.[9][10] In terms of jobs outlook, it is predicted that there will only be a 2% increase in job growth from 2022 to 2032 in the United States. Approximately 12,200 openings are expected each year in this decade. Most of the new jobs are likely to be offered to replace roofers who retire or transition out of the trade.[1]
In Australia, this type of carpenter is called a roof carpenter and the term roofer refers to someone who installs the roof cladding (tiles, tin, etc.). The number of roofers in Australia was estimated to be approximately 15,000. New South Wales is the largest province with an 29% market share in the Australian Roofers industry (4,425 companies). Second is Victoria with 3,206 Roofers (21%).[11]
In the United States and Canada, they're often referred to as roofing contractors or roofing professionals. The most common roofing material in the United States is asphalt shingles. In the past, 3-tab shingles were used, but recent trends show "architectural" or "dimensional" shingles becoming very popular.[12]
Depending on the region, other commonly applied roofing materials installed by roofers include concrete tiles, clay tiles, natural or synthetic slate, single-ply (primarily EPDM rubber, PVC, or TPO), rubber shingles (made from recycled tires), glass, metal panels or shingles, wood shakes or shingles, liquid-applied, hot asphalt/rubber, foam, thatch, and solar tiles. "Living roof" systems, or rooftop landscapes, have become increasingly common in recent years in both residential and commercial applications.[13][14]
Roles and responsibilities of roofing professionals include:[1]
Beyond having common duties such as replacing, repairing, or installing roofs for buildings, roofers can also be involved in other tasks, including but is not limited to:
Roofing is one of the most dangerous professions among construction occupations since it involves working at heights and exposes workers to dangerous weather conditions such as extreme heat.[15] In the United States as of 2017, the rate of fatalities from falls among roofers is 36 deaths per 100,000 full-time employees, ten times greater than all construction-related professions combined.[16] In the United States, the fatal injury rate in 2021 was 59.0 per 100,000 full-time roofers, compared to the national average of 3.6 per 100,000 full-time employees.[17] According to the U.S. Bureau of Labor Statistics, roofing has been within the top 5 highest death rates of any profession for over 10 years in a row.[18] For Hispanic roofers, data from 2001–2008 show fatal injuries from falls account for nearly 80% of deaths in this population, the highest cause of death among Hispanics of any construction trade.[19][20]
A major contributing factor to the high fatality rates among roofers in the United States is the nature of the craft which requires roofers to work on elevated, slanted roof surfaces. Findings from qualitative interviews with Michigan roofing contractors also found hand and finger injuries from handling heavy material and back injuries to be some of the more common task/injury combinations.[21]
Ladder falls contribute to the rates of injury and mortality. More than half a million people per year are treated for fall from ladder and over 3000 people die as a result.[22] In 2014 the estimated cost annual cost of ladder injuries, including time away from work, medical, legal, liability expenses was estimated to reach $24 billion.[22] Male, Hispanic, older, self-employed workers and those who work in smaller establishments, and work doing construction, maintenance, and repair experience higher ladder fall injury rates when compared with women and non-Hispanic whites and persons of other races/ethnicities.[23]
Ladders allow for roofers to access upper level work surfaces. For safe use, ladder must be inspected for damage by a competent person and must be used on stable and level surfaces unless they are secured to prevent displacement.[3]
Nearly every industrialized country has established specific safety regulations for work on the roof, ranging from the use of conventional fall protection systems including personal fall arrest systems, guardrail systems, and safety nets.
The European Agency for Safety and Health at Work describes scenarios of risk (fall prevention, falling materials, types of roofs), precautions, training needed and European legislation focused on roof work.[6] European directives set minimum standards for health and safety and are transposed into law in all Member States.
In the United States, OSHA standards require employers to have several means of fall protection available to ensure the safety of workers. In construction, this applies to workers who are exposed to falls of 6 feet or more above lower levels.[3][24] In the United States, regulation of the roofing trade is left up to individual states. Some states leave roofing regulation up to city-level, county-level, and municipal-level jurisdictions. Unlicensed contracting of projects worth over a set threshold may result in stiff fines or even time in prison. In some states, roofers are required to meet insurance and roofing license guidelines. Roofers are also required to display their license number on their marketing material.
Canada's rules are very similar to those from the U.S., and regulatory authority depends on where the business is located and fall under the authority of their local province.
In 2009, in response to high rates of falls in constructions the Japanese Occupational Safety and Health Regulations and Guidelines amended their specific regulations. In 2013 compliance was low and the need for further research and countermeasures for preventing falls and ensuring fall protection from heights was identified.[25]
The United Kingdom has no legislation in place that requires a roofer to have a license to trade, although some do belong to recognized trade organizations.[26]
The purpose of a PFAS is to halt a fall and prevent the worker from making bodily contact with a surface below. The PFAS consists of an anchorage, connectors, body harness and may include a lanyard, deceleration device, lifeline or suitable combination of these.
Beyond these mandatory components of the PFAS, there are also specific fall distances associated with the functioning of the arrest system. Specifically, there is a total fall distance that the PFAS must allow for to assist the worker in avoiding contact with the ground or other surface below. The total fall distance consists of free fall distance, deceleration distance, D-ring shift, Back D-ring height, and Safety margin. In addition to the fall distance requirements for each component of the PFAS, the anchorage of the PFAS must also be able to support a minimum 5,000 pounds per worker.[4]
OSHA regulations have several requirements. The free fall distance, to the distance that the worker drops before the PFAS begins to work and slows the speed of the fall, must be 6 feet or less, nor contact any lower level. The deceleration, the length that the lanyard must stretch in order to arrest the fall must be no more than 3.5 feet.[4] The D-ring shift, the distance that the harness stretches and how far the D-ring itself moves when it encounters the full weight of the worker during a fall, is generally assumed to be 1 foot, depending on the equipment design and the manufacturer of the harness. For the back D-ring height, the distance between the D-ring and the sole of the worker's footwear, employers often use 5 feet as the standard height with the assumption that the worker will be 6 feet in height, but because the D-ring height variability can affect the safety of the system, the back D-ring height must be calculated based on the actual height of the worker. The safety margin, the additional distance that is needed to ensure sufficient clearance between the worker and the surface beneath the worker after a fall occurs, is generally considered to be a minimum of 2 feet.[3]
A fall restraint system is a type of fall protection system where, the goal is to stop workers from reaching the unprotected sides or edges of a working area in which a fall can subsequently occur. This system is useful where a worker may lose their footing near an unprotected edge or begin sliding. In such a case, the fall restraint system will restrain further movement of the worker toward the unprotected side or edge and prevent a serious fall. Although fall restraint systems are not explicitly defined or mentioned in OSHA's fall protection standards for construction,[24][4] they are allowed by OSHA as specified in an OSHA letter of interpretation last updated in 2004.[27] OSHA does not have any specific requirements for fall restraint systems, but recommends that any fall restraint system be capable of withstanding 3,000 pounds or at least twice the maximum predicted force necessary to save the worker from falling to the lower surface.[3] There are no OSHA specifications on the distance from the edge the restraint system must allow for a falling worker, and although a likely very dangerous practice, the OSHA letter of interpretation states that as long as the restraint system prevents the employee from falling off an edge, the employee can be restrained to "within inches of the edge."[27]
Guardrail systems serve as an alternative to PFAS and fall restraint systems by having permanent or temporary guardrails around the perimeter of the roof and any roof openings. OSHA requires the height of the top of the rail to be 39-45 inches above the working surface. Mid-rails must be installed midway between the top of the top rail and the walking/working surface when there is no parapet wall at least 21 inches high. Guardrail systems must be capable of withstanding 200-pounds of force in any outward or downward direction applied within 2 inches of the top edge of the rail.[3][24]
Safety net systems use a tested safety net adjacent to and below the edge of the walking/working surface to catch a worker who may fall off the roof. Safety nets must be installed as close as practicable under the surface where the work is being performed and shall extend outward from the outermost projection of the work surface as follows:[4]
[4]
Safety nets must be drop-tested with a 400-pound bag of sand, or submit a certification record prior to its initial use.[4]
Warning lines systems consist of ropes, wires, or chains which are marked every 6 feet with high-visibility material, and must be supported in such a way so that it is between 34 and 39 inches above the walking/working surface.[4] Warning lines are passive systems that allow for a perimeter to be formed around the working area so that workers are aware of dangerous edges. Warning lines are only permitted on roofs with a low slope (having a slope of less than or equal to 4 inches of vertical rise for every 12 inches horizontal length (4:12)).[28] In the context of roofing fall protection, warning line systems may only be used in combination with a guardrail system, a safety net system, a personal fall arrest system, or a safety monitoring system. The warning line system must be erected around all sides of the roof work area.[4]
Safety monitoring systems use safety monitors to monitor the safety of other workers on the roof. Safety monitors must be competent to recognize fall hazards. The safety monitor is tasked to ensure the safety of other workers on the roof and must be able to orally warn an employee when they are in an unsafe situation.[4]
Multi-layered approaches to fall prevention and protection that use the hierarchy of controls can help to prevent fall injuries, incidents, and fatalities in the roofing industry.[7][8] The hierarchy of controls is a way of determining which actions will best control exposures. The hierarchy of controls has five levels of actions to reduce or remove hazards – elimination, substitution, and engineering controls are among the preferred preventive actions based on general effectiveness.
Resources are available to assist with the implementation of fall safety measures in the roofing industry such as fall prevention plans,[23][29] a ladder safety mobile application,[30] infographics and tipsheets,[31] toolbox talks,[32] videos and webinars,[1] and safety leadership training.[2] Many of these resources are available in Spanish and additional languages other than English. The recommended safety measures are described next.
In terms of job outlooks, it is predicted that there will only be an 1% increase in job growth from 2021 to 2032. The job openings (15,000) are expected to replace roofers who will retire or transition out of the trade.[9]
Solar Roof installation is one of the fastest growing trends in the roofing industry due to the nature of solar roofs being environmentally friendly and a worthwhile economic investment. Specifically, solar roofs have been found to allow homeowners to potentially save 40-70% on electric bills depending on the number of tiles installed.[33] The US federal government has also begun incentivizing homeowners to install solar roofs with potential eligibility for 30% tax credit on the cost of a solar system based on federal income taxes.[34]
Across 14 researched markets, roofing contracting companies have reported that they have received more frequent calls regarding potential metal roof installations. For instance, one company used to receive 5-6 calls in total regarding metal installations but recently, they have received 5-6 calls weekly for inquiries regarding metal roof installations.[35]
A roof (pl.: roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of temperature, and wind.[1] A roof is part of the building envelope.
The characteristics of a roof are dependent upon the purpose of the building that it covers, the available roofing materials and the local traditions of construction and wider concepts of architectural design and practice, and may also be governed by local or national legislation. In most countries, a roof protects primarily against rain. A verandah may be roofed with material that protects against sunlight but admits the other elements. The roof of a garden conservatory protects plants from cold, wind, and rain, but admits light.
A roof may also provide additional living space, for example, a roof garden.
Old English hrof[2] 'roof, ceiling, top, summit; heaven, sky', also figuratively, 'highest point of something', from Proto-Germanic *khrofam (cf. Dutch roef 'deckhouse, cabin, coffin-lid', Middle High German rof 'penthouse', Old Norse hrof 'boat shed'). There are no apparent connections outside the Germanic family. "English alone has retained the word in a general sense, for which the other languages use forms corresponding to OE. þæc thatch".[3]
The elements in the design of a roof are:
The material of a roof may range from banana leaves, wheaten straw or seagrass to laminated glass, copper (see: copper roofing), aluminium sheeting and pre-cast concrete. In many parts of the world ceramic roof tiles have been the predominant roofing material for centuries, if not millennia. Other roofing materials include asphalt, coal tar pitch, EPDM rubber, Hypalon, polyurethane foam, PVC, slate, Teflon fabric, TPO, and wood shakes and shingles.
The construction of a roof is determined by its method of support and how the underneath space is bridged and whether or not the roof is pitched. The pitch is the angle at which the roof rises from its lowest to its highest point. Most US domestic architecture, except in very dry regions, has roofs that are sloped, or pitched. Although modern construction elements such as drainpipes may remove the need for pitch, roofs are pitched for reasons of tradition and aesthetics. So the pitch is partly dependent upon stylistic factors, and partially to do with practicalities.
Some types of roofing, for example thatch, require a steep pitch in order to be waterproof and durable. Other types of roofing, for example pantiles, are unstable on a steeply pitched roof but provide excellent weather protection at a relatively low angle. In regions where there is little rain, an almost flat roof with a slight run-off provides adequate protection against an occasional downpour. Drainpipes also remove the need for a sloping roof.
A person that specializes in roof construction is called a roofer.
The durability of a roof is a matter of concern because the roof is often the least accessible part of a building for purposes of repair and renewal, while its damage or destruction can have serious effects.
The shape of roofs differs greatly from region to region. The main factors which influence the shape of roofs are the climate and the materials available for roof structure and the outer covering.[4]
The basic shapes of roofs are flat, mono-pitched, gabled, mansard, hipped, butterfly, arched and domed. There are many variations on these types. Roofs constructed of flat sections that are sloped are referred to as pitched roofs (generally if the angle exceeds 10 degrees).[5] Pitched roofs, including gabled, hipped and skillion roofs, make up the greatest number of domestic roofs. Some roofs follow organic shapes, either by architectural design or because a flexible material such as thatch has been used in the construction.
There are two parts to a roof: its supporting structure and its outer skin, or uppermost weatherproof layer. In a minority of buildings, the outer layer is also a self-supporting structure.
The roof structure is generally supported upon walls, although some building styles, for example, geodesic and A-frame, blur the distinction between wall and roof.
The supporting structure of a roof usually comprises beams that are long and of strong, fairly rigid material such as timber, and since the mid-19th century, cast iron or steel. In countries that use bamboo extensively, the flexibility of the material causes a distinctive curving line to the roof, characteristic of Oriental architecture.
Timber lends itself to a great variety of roof shapes. The timber structure can fulfil an aesthetic as well as practical function, when left exposed to view.
Stone lintels have been used to support roofs since prehistoric times, but cannot bridge large distances. The stone arch came into extensive use in the ancient Roman period and in variant forms could be used to span spaces up to 45 m (140 ft) across. The stone arch or vault, with or without ribs, dominated the roof structures of major architectural works for about 2,000 years, only giving way to iron beams with the Industrial Revolution and the designing of such buildings as Paxton's Crystal Palace, completed 1851.
With continual improvements in steel girders, these became the major structural support for large roofs, and eventually for ordinary houses as well. Another form of girder is the reinforced concrete beam, in which metal rods are encased in concrete, giving it greater strength under tension.
Roof support can also serve as living spaces as can be seen in roof decking. Roof decking are spaces within the roof structure that is converted into a room of some sort.
This part of the roof shows great variation dependent upon availability of material. In vernacular architecture, roofing material is often vegetation, such as thatches, the most durable being sea grass with a life of perhaps 40 years. In many Asian countries bamboo is used both for the supporting structure and the outer layer where split bamboo stems are laid turned alternately and overlapped. In areas with an abundance of timber, wooden shingles, shakes and boards are used, while in some countries the bark of certain trees can be peeled off in thick, heavy sheets and used for roofing.
The 20th century saw the manufacture of composition asphalt shingles which can last from a thin 20-year shingle to the thickest which are limited lifetime shingles, the cost depending on the thickness and durability of the shingle. When a layer of shingles wears out, they are usually stripped, along with the underlay and roofing nails, allowing a new layer to be installed. An alternative method is to install another layer directly over the worn layer. While this method is faster, it does not allow the roof sheathing to be inspected and water damage, often associated with worn shingles, to be repaired. Having multiple layers of old shingles under a new layer causes roofing nails to be located further from the sheathing, weakening their hold. The greatest concern with this method is that the weight of the extra material could exceed the dead load capacity of the roof structure and cause collapse. Because of this, jurisdictions which use the International Building Code prohibit the installation of new roofing on top of an existing roof that has two or more applications of any type of roof covering; the existing roofing material must be removed before installing a new roof.[6]
Slate is an ideal, and durable material, while in the Swiss Alps roofs are made from huge slabs of stone, several inches thick. The slate roof is often considered the best type of roofing. A slate roof may last 75 to 150 years, and even longer. However, slate roofs are often expensive to install – in the US, for example, a slate roof may have the same cost as the rest of the house. Often, the first part of a slate roof to fail is the fixing nails; they corrode, allowing the slates to slip. In the UK, this condition is known as "nail sickness". Because of this problem, fixing nails made of stainless steel or copper are recommended, and even these must be protected from the weather.[7]
Asbestos, usually in bonded corrugated panels, has been used widely in the 20th century as an inexpensive, non-flammable roofing material with excellent insulating properties. Health and legal issues involved in the mining and handling of asbestos products means that it is no longer used as a new roofing material. However, many asbestos roofs continue to exist, particularly in South America and Asia.
Roofs made of cut turf (modern ones known as green roofs, traditional ones as sod roofs) have good insulating properties and are increasingly encouraged as a way of "greening" the Earth. The soil and vegetation function as living insulation, moderating building temperatures.[8] Adobe roofs are roofs of clay, mixed with binding material such as straw or animal hair, and plastered on lathes to form a flat or gently sloped roof, usually in areas of low rainfall.
In areas where clay is plentiful, roofs of baked tiles have been the major form of roofing. The casting and firing of roof tiles is an industry that is often associated with brickworks. While the shape and colour of tiles was once regionally distinctive, now tiles of many shapes and colours are produced commercially, to suit the taste and pocketbook of the purchaser. Concrete roof tiles are also a common choice, being available in many different styles and shapes.
Sheet metal in the form of copper and lead has also been used for many hundreds of years. Both are expensive but durable, the vast copper roof of Chartres Cathedral, oxidised to a pale green colour, having been in place for hundreds of years. Lead, which is sometimes used for church roofs, was most commonly used as flashing in valleys and around chimneys on domestic roofs, particularly those of slate. Copper was used for the same purpose.
In the 19th century, iron, electroplated with zinc to improve its resistance to rust, became a light-weight, easily transported, waterproofing material. Its low cost and easy application made it the most accessible commercial roofing, worldwide. Since then, many types of metal roofing have been developed. Steel shingle or standing-seam roofs last about 50 years or more depending on both the method of installation and the moisture barrier (underlayment) used and are between the cost of shingle roofs and slate roofs. In the 20th century, a large number of roofing materials were developed, including roofs based on bitumen (already used in previous centuries), on rubber and on a range of synthetics such as thermoplastic and on fibreglass.
A roof assembly has more than one function. It may provide any or all of the following functions: 1. To shed water i.e., prevent water from standing on the roof surface. Water standing on the roof surface increases the live load on the roof structure, which is a safety issue. Standing water also contributes to premature deterioration of most roofing materials. Some roofing manufacturers' warranties are rendered void due to standing water. 2. To protect the building interior from the effects of weather elements such as rain, wind, sun, heat and snow. 3. To provide thermal insulation. Most modern commercial/industrial roof assemblies incorporate insulation boards or batt insulation. In most cases, the International Building Code and International Residential Code establish the minimum R-value required within the roof assembly. 4. To perform for the expected service life. All standard roofing materials have established histories of their respective longevity, based on anecdotal evidence. Most roof materials will last long after the manufacturer's warranty has expired, given adequate ongoing maintenance, and absent storm damage. Metal and tile roofs may last fifty years or more. Asphalt shingles may last 30–50 years. Coal tar built-up roofs may last forty or more years. Single-ply roofs may last twenty or more years. 5. Provide a desired, unblemished appearance. Some roofs are selected not only for the above functions, but also for aesthetics, similar to wall cladding. Premium prices are often paid for certain systems because of their attractive appearance and "curb appeal."
Because the purpose of a roof is to secure people and their possessions from climatic elements, the insulating properties of a roof are a consideration in its structure and the choice of roofing material.
Some roofing materials, particularly those of natural fibrous material, such as thatch, have excellent insulating properties. For those that do not, extra insulation is often installed under the outer layer. In developed countries, the majority of dwellings have a ceiling installed under the structural members of the roof. The purpose of a ceiling is to insulate against heat and cold, noise, dirt and often from the droppings and lice of birds who frequently choose roofs as nesting places.
Concrete tiles can be used as insulation. When installed leaving a space between the tiles and the roof surface, it can reduce heating caused by the sun.
Forms of insulation are felt or plastic sheeting, sometimes with a reflective surface, installed directly below the tiles or other material; synthetic foam batting laid above the ceiling and recycled paper products and other such materials that can be inserted or sprayed into roof cavities. Cool roofs are becoming increasingly popular,[9] and in some cases are mandated by local codes. Cool roofs are defined as roofs with both high reflectivity and high thermal emittance.[9]
Poorly insulated and ventilated roofing can suffer from problems such as the formation of ice dams around the overhanging eaves in cold weather, causing water from melted snow on upper parts of the roof to penetrate the roofing material. Ice dams occur when heat escapes through the uppermost part of the roof, and the snow at those points melts, refreezing as it drips along the shingles, and collecting in the form of ice at the lower points. This can result in structural damage from stress, including the destruction of gutter and drainage systems.
The primary job of most roofs is to keep out water. The large area of a roof repels a lot of water, which must be directed in some suitable way, so that it does not cause damage or inconvenience.
Flat roof of adobe dwellings generally have a very slight slope. In a Middle Eastern country, where the roof may be used for recreation, it is often walled, and drainage holes must be provided to stop water from pooling and seeping through the porous roofing material.
While flat roofs are more prone to drainage issues, poorly designed or textured sloping roofs can face similar problems.[10] Standing water on a roof can lead to mold growth, which is highly damaging to both the building’s structure and the health of its occupants. Repairing drainage issues is significantly less costly than fixing the damage caused by mold.[11]
Similar problems, although on a very much larger scale, confront the builders of modern commercial properties which often have flat roofs. Because of the very large nature of such roofs, it is essential that the outer skin be of a highly impermeable material. Most industrial and commercial structures have conventional roofs of low pitch.
In general, the pitch of the roof is proportional to the amount of precipitation. Houses in areas of low rainfall frequently have roofs of low pitch while those in areas of high rainfall and snow, have steep roofs. The longhouses of Papua New Guinea, for example, being roof-dominated architecture, the high roofs sweeping almost to the ground. The high steeply-pitched roofs of Germany and Holland are typical in regions of snowfall. In parts of North America such as Buffalo, New York, United States, or Montreal, Quebec, Canada, there is a required minimum slope of 6 in 12 (1:2, a pitch of 30°).
There are regional building styles which contradict this trend, the stone roofs of the Alpine chalets being usually of gentler incline. These buildings tend to accumulate a large amount of snow on them, which is seen as a factor in their insulation. The pitch of the roof is in part determined by the roofing material available, a pitch of 3 in 12 (1:4) or greater slope generally being covered with asphalt shingles, wood shake, corrugated steel, slate or tile.
The water repelled by the roof during a rainstorm is potentially damaging to the building that the roof protects. If it runs down the walls, it may seep into the mortar or through panels. If it lies around the foundations it may cause seepage to the interior, rising damp or dry rot. For this reason most buildings have a system in place to protect the walls of a building from most of the roof water. Overhanging eaves are commonly employed for this purpose. Most modern roofs and many old ones have systems of valleys, gutters, waterspouts, waterheads and drainpipes to remove the water from the vicinity of the building. In many parts of the world, roofwater is collected and stored for domestic use.
Areas prone to heavy snow benefit from a metal roof because their smooth surfaces shed the weight of snow more easily and resist the force of wind better than a wood shingle or a concrete tile roof.
Newer systems include solar shingles which generate electricity as well as cover the roof. There are also solar systems available that generate hot water or hot air and which can also act as a roof covering. More complex systems may carry out all of these functions: generate electricity, recover thermal energy, and also act as a roof covering.
Solar systems can be integrated with roofs by:
A roof’s shingles are a roof covering consisting of individual overlapping elements. These elements are typically flat, rectangular shapes laid in courses from the bottom edge of the roof up, with each successive course overlapping the joints below. Shingles are held by the roof rafters and are made of various materials such as wood, slate, flagstone, metal, plastic, and composite materials such as fibre cement and asphalt shingles. Ceramic roof tiles, which still dominate in Europe and some parts of Asia, are still usually called tiles. Roof shingles may deteriorate faster and need to repel more water than wall shingles. They are a very common roofing material in the United States.
Shingle is a corruption of German Schindel meaning a roofing slate.[1] Shingles historically were called tiles, and shingle was a term applied to wood shingles,[1] as is still mostly the case outside the US.
Shingles are laid in courses, usually with each shingle offset from its neighbors. The first course is the starter course and the last being a ridge course or ridge slates for a slate roof. The ridge is often covered with a ridge cap, board, piece, or roll,[2] sometimes with a special ridge vent material.
Roof shingles are almost always highly visible and so are an important aspect of a building's aesthetics in patterns, textures and colors. Roof shingles, like other building materials on vernacular buildings, are typically of a material locally available. The type of shingle is taken into account before construction because the material affects the roof pitch and construction method: Some shingles can be installed on lath where others need solid sheathing (sheeting) on the roof deck. All shingle roofs are installed from the bottom upward beginning with a starter course and the edge seams offset to avoid leaks. Many shingle installations benefit from being placed on top of an underlayment material such as asphalt felt paper to prevent leaks even from wind driven rain and snow and ice dams in cold climates. At the ridge the shingles on one side of the roof simply extend past the ridge or there is a ridge cap consisting of boards, copper, or lead sheeting. An asphalt shingle roof has flexible asphalt shingles as the ridge cap. Some roof shingles are non-combustible or have a better fire rating than others which influence their use, some building codes do not allow the use of shingles with less than a class-A fire rating to be used on some types of buildings. Due to increased fire hazard, wood shingles and organic-based asphalt shingles have become less common than fiberglass-based asphalt shingles. No shingles are water-tight so the minimum recommended roof pitch is 4:12 without additional underlayment materials.[3]
In the United States, fiberglass-based asphalt shingles are by far the most common roofing material used for residential roofing applications. In Europe, they are called bitumen roof shingles or tile strips, and are much less common.[4] They are easy to install, relatively affordable, last 20 to 60 years and are recyclable in some areas. Asphalt shingles come in numerous styles and colors.[5]
The protective nature of paper and fiberglass asphalt shingles primarily comes from the long-chain petroleum hydrocarbons, while wood shingles are protected by natural oils in the cellulose structure. Over time in the hot sun, these oils soften and when rain falls the oils are gradually washed out of the shingles. During rain, more water is channeled along eaves and complex rooflines, and these are subsequently more prone to erosion than other areas.
Eventually the loss of the oils causes asphalt shingle fibers to shrink and wood shingles to rot, exposing the nail heads under the shingles. Once the nail heads are exposed, water running down the roof can seep into the building around the nail shank, resulting in rotting of underlying roof building materials and causing moisture damage to ceilings and paint inside.
Two basic types of wood shingles are called shingles and shakes. Wood shakes are typically longer and thicker than wood shingles. The main difference is in how they are made, with shingles always being sawn and shakes normally being split, at least on one side.[6] A wood shake is often more textured, as it is split following the natural grain of the wood rather than sawn against it like the shingle. Untreated wood shingles and shakes have long been known as a fire hazard and have been banned in various places, particularly in urban areas where exterior, combustible building materials contribute to devastating fires known as conflagrations. Modern pressure-impregnated fire retardant treated wood shakes and shingles can achieve a Class B fire rating, and can achieve a Class A rating when used in conjunction with specially designed roof assemblies.[7]
The use of wooden roof shingles has existed in parts of the world with a long tradition of wooden buildings, especially Scandinavia, and Central and Eastern Europe. Nearly all the houses and buildings in colonial Chiloé were built with wood, and roof shingles were extensively employed in Chilota architecture.
Slate shingles are also called slate tiles, the usual name outside the US. Slate roof shingles are relatively expensive to install but can last 80 to 400 years depending on the quality of the slate used, and how well they are maintained. The material itself deteriorates only slowly, and may be recycled from one building to another.
The primary means of failure in a slate roof is when individual slates lose their peg attachment and begin to slide out of place. This can open up small gaps above each slate. A secondary mode of failure is when the slates themselves begin to break up. The lower parts of a slate may break loose, giving a gap below a slate. Commonly the small and stressed area above the nail hole may fail, allowing the slate to slip as before. In the worst cases, a slate may simply break in half and be lost altogether. A common repair to slate roofs is to apply 'torching', a mortar fillet underneath the slates, attaching them to the battens. This may apply as either a repair, to hold slipping slates, or pre-emptively on construction.
Where slates are particularly heavy, the roof may begin to split apart along the roofline. This usually follows rot developing and weakening the internal timbers, often as a result of poor ventilation within the roof space. An important aspect to slate roofs is the use of a metal flashing which will last as long as the slates. Slate shingles may be cut in a variety of decorative patterns and are available in several colors.
Flagstone shingles are a traditional roofing material. Some stone shingles are fastened in place but some simply are held by gravity, so the roof pitch cannot be too steep or the stones will slide off the roof. Sandstone has also been used to make shingles.
Fibre cement shingles are often known by their manufacturer's name, such as Eternit or Transite. Often, the fiber in the cement material was asbestos, the use of which has been banned since the 1980s, for health reasons. The removal of shingles containing asbestos requires extra precautions and special disposal methods.
Metal shingles are a type of roofing material that offers the appeal of traditional shingles, such as wood, tile, and slate, while providing high fire resistance and durability. They are crafted from durable heavy-gauge aluminum and designed to emulate the classic appearance of traditional slate, cedar shingles, and other materials. Metal shingles are extremely fire resistant, so are used in fire prone areas. [8]
Plastic has been used to produce imitation slate shingles. These are lightweight and durable, but combustible. Also, they are very lightweight and are one of the cheapest shingles to have installed.[9]
Cedar shingles are resistant to rot and commonly available in lengths of 18 and 24 inches (460 and 610 mm). These fade gradually from natural wood colored to a silver-like tone. Types include hand-split resawn shakes, tapersplit shakes or tapersawn shakes.
Composite or synthetic shingles are a relatively new type of shingle material that are made from a blend of materials, including asphalt, fiberglass, and other polymers. These shingles are designed to mimic the look of natural materials such as wood, slate, or clay and aim to increase the durability, strength, and resistance to weather elements relative to these natural materials. Some examples of manufacturers of synthetic or composite roof shingles are DaVinci Roofscapes or Unified Steel.
Rubber shingle roofs are typically made from 95% recycled material from a variety of sources including recycled tires. They last twice as long as asphalt shingles but are about twice the price as asphalt. They are more quiet than most roofs, hail resistant, and a high wind rating if there is a tongue and groove fitting at the front edge of the rubber shingle design.[10][11]
VNPS recently installed a new roof on our home in Odessa. Suffice it to say that Reuben and his team exceeded my expectations from start to finish. The communication and workmanship were superior from start to finish. I highly recommend this company for your next roofing project. Brian Harre Owner of Northside Services
What a great experience with my roof. This is my second roof in 6 years (old company shingles disintigrated) and they were amazing to work with. The communications with the inside staff was awesome, kept me up to date the entire time, when the crew would arrive, why they had to dlay and more. It took 2 days versus the 4 they said it may take. They cleaned up well. Pricing was awesome, super professional and more. I would highly recommend this company, and I am not one to give 5 stars or review companies that often.
Ruben and his team were great to work with. Amanda kept me informed on the start date and what to expect during the reroofing process. The roofers were very kind and professional. They arrived and got to work right away. They left a clean job and made sure to check for nails around the property. Will definitely use them again.
VNPS were very professional from the start. They presented top of the line materials, excellent price (the best I could find) with Veterans discounts, and once selected, they were very detailed and quality workmanship. I'm very pleased with the total experience. They even provided documentation that caused a substantial decrease in our house insurance cost.