File Name: roofs and roof coverings .zip
A roof 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.
- 9 different types of roofing materials
- Pitched and Flat Roofs
- What Materials are Used for Roofing?
- Pitched and Flat Roofs
Search How to Titles Subjects Organizations. Different roof shapes Technical terms of a roof Rafter and ridge roof
9 different types of roofing materials
A roof 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. 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. 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. 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 tiles have been the predominant roofing material for centuries, if not millennia. 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 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.
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. 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 midth 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 or vault , with or without ribs, dominated the roof structures of major architectural works for about 2, years, only giving way to iron beams with the Industrial Revolution and the designing of such buildings as Paxton 's Crystal Palace , completed 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. 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 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 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.
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 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. 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. 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. 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.
Stone used as roofing material in Himachal Pradesh , India. A roof assembly has more than one function. It may provide any or all of the following functions: 1. To shed water i. 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. To protect the building interior from the effects of weather elements such as rain, wind, sun, heat and snow. To provide thermal insulation. In most cases, the International Building Code and International Residential Code establish the minimum R-value required within the roof assembly.
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 years. Coal tar built-up roofs may last forty or more years. Single-ply roofs may last twenty or more years. 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.
Pitched and Flat Roofs
A building permit PDF is required for installing roofing. In order to apply for a building permit you need to either be a licensed state residential contractor or the property owner PDF. See roofing handout PDF for more details. New roof coverings shall not be installed without first removing all existing layers of roof coverings if any of the following conditions exist; The existing roof or roof covering is water-soaked or deteriorated to a point where the roof or roof covering is not adequate as a base. The existing roof has two layers or more of any type of roof coverings.
Roof and Roof Covering - Free download as Powerpoint Presentation .ppt), PDF File .pdf), Text File .txt) or view presentation slides online. Roofs may be divided into three categories: Pitched or sloping roofs Flat roofs or.
What Materials are Used for Roofing?
Building Quantities Explained pp Cite as. Both flat and pitched roofs can conveniently be subdivided into two main sections for purposes of measurement, that is, construction and coverings. The order of measurement of these two sections varies in practice, but on balance it is probably better to take the construction first since this follows the order of erection on the site. Unable to display preview.
Pitched and Flat Roofs
Not long ago, asphalt shingles, slate, clay or concrete tiles were about the only roofing options. Today, advanced roofing materials provide an unprecedented range of alternatives, as well as new looks for existing materials. Advanced solar collectors integrate seamlessly into existing shingles, generating up to 1 kilowatt of energy per square feet. While they may help offset energy costs with solar power, they also cost more than traditional solar options.
A roof consists of structural elements which support roof coverings. The structural elements may be trusses, portals, beams, slabs with or without beams , shells or domes. The roof coverings may be A. C sheets, G. I sheets, wooden shingle, tiles, slates or slab itself.
Roof consists of structural elements which support roof is roof covering. The roof coverings may be A.C. sheets, G.I. sheets, wooden shingles, tiles, slab itself.
Lead Flashing Alternatives. Concrete Roof Tiles. Roof Tile Clips. Clay Roof Tiles. Slate Roof Tiles. Metal Roof Tiles. Tile Vents.
A roof system consists of various types of materials that are interconnected in order to provide weatherproof protection in buildings. In addition to being waterproof, roofs help protect buildings from the sun, rain, snow, and other elements. Roofing materials vary depending on the shape of the roof, location and climate, and whether the use is for residential or commercial. Asphalt shingles are popular for residential use as they are fairly inexpensive and have a good lifespan. In commercial construction where flat roofs are more common, metal, EPDM, and built-up roofs are extensively used.
Нет. - Может быть, сказала, куда идет. - Нет. По-испански говорила очень плохо. - Она не испанка? - спросил Беккер. - Нет.
Но надо идти вперед, а не оглядываться все время. - В трубке воцарилась тишина, и Джабба подумал, что зашел слишком. - Прости меня, Мидж.
От неожиданности Сьюзан застыла на месте. Она была уверена, что никогда не говорила с шефом о поездке. Она повернулась. Неужели АНБ прослушивает мои телефонные разговоры.
Беккер так и не узнал, какие страшные секреты он помог раскрыть, ни одна вещь не вызывала у него никаких сомнений. АНБ очень серьезно относилось к дешифровке. Полученный чек превышал его месячное университетское жалованье.
Я прихожу сюда каждый вечер. Подними, говорю. Беккер терял терпение. А ведь он мог быть сейчас в Смоки-Маунтинс, со Сьюзан.
Он прав. Я читала об .