Roofs Construction <ul><li>Done By: </li></ul><ul><li>Tariq Hafez M.A. Nimeer </li></ul><ul><li>[email_address] </li></ul>
roof is the covering on the uppermost part of a building. A roof protects the building and its contents from the effects of weather. Structures that require roofs range from a letter box to a cathedral or stadium, dwellings being the most numerous. In most countries a roof protects primarily against rain. Depending upon the nature of the building, the roof may also protect against heat, against sunlight, against cold and against wind. What is The Roof ???
Roofing Terminology <ul><li>Hip The external angle at the junction of two sides of a roof whose supporting walls adjoin. </li></ul><ul><li>Joist In a flat roof, a horizontal structural member over which sheathing is nailed. </li></ul><ul><li>Rafter A structural member (usually slanted) to which sheathing is nailed. </li></ul><ul><li>Flashing Sheet metal or other material used at junctions of different planes on a roof to prevent leakage. </li></ul><ul><li>Gable The triangular upper part of a wall closing the end of a ridged roof </li></ul><ul><li>Ridge The horizontal line at the top edge of two sloping roof planes. </li></ul><ul><li>Valley The less-than 180-degree angle where two sloping roof sections come together </li></ul>
Roofing Terminology …… <ul><li>Drip The strip of metal extending out beyond the eaves or rakes to prevent rainwater from rolling around the shingles back onto the wooden portion of the house. </li></ul><ul><li>Fascia Trim board behind the gutter and eaves. </li></ul><ul><li>Shingle Flashing Flashing that is laid in strips under each shingle and bent up the edge of a chimney or wall </li></ul><ul><li>Underlayment The material (usually roofing felt) laid on top of sheathing before shingles are applied. </li></ul><ul><li>Soffit The boards that enclose the underside of that portion of the roof which extends out beyond the sidewalls of the house. </li></ul>
Brief History of Roofing <ul><li>The history of roofing has come an extremely long way. Man has utilized various natural resources throughout history to create the environmentally safe, effective roofing of today. From wood, mud and straw, to tiling, shingles and beyond. </li></ul><ul><li>As one can imagine, a roof can only be as good as the materials readily available, so every civilization had varying methods, tools, and materials for creating their respective roofs. </li></ul>The roof of Pantheon doom damp clay and earth on the roof of Greek temple <ul><li>Although most of the growth within the roofing industry has been within the last 200 years, the complete history of roofing starts much earlier than that. </li></ul><ul><li>The Greeks and Romans were the first to experiment with differing roofing styles. The Romans introduced slating and tiling to Great Britain as early as 100 BC. </li></ul><ul><li>Thatch roofs were introduced and implemented around the year 735 AD and it wouldn’t be for another 300 years until wooden shingles were first implemented as well. </li></ul>
until the 12th century that the history of roofing was changed under King John, when he issued a law in London that citizens had to replace their thatch and reed roof-coverings and replace them with clay tiles. Dreadnought clay tiles began production in 1805 and industrial roofing at that time had little insulation but a good slope for rainwater and other debris. One hundred year after that, concrete tile roofing was first utilized. Brief History of Roofing….. While the history of roofing began to evolve In the southern parts of the United States, wood and metal were more widely used. Even to this day, roofing styles are still based around wood and metal, It is hard to predict the future of the roofing industry and what technology can shape for the future, but for certain, the history of roofing has evolved and will continue to evolve forever.
Flat A flat roof is not truly flat but angled slightly to allow for water runoff. It is the cheapest to build initially but will cost you much more than other roof types in maintenance costs.
Shed A shed roof is basically a flat roof with a slightly greater angle allowing for greater runoff. They are relatively easy to build and inexpensive as compared to most other roof types. They are usually used on home extension rooms and porches
Gable Gable Dormers Dormers are room construction extensions from the roof structure. They usually have windows or doors on the front wall structure. Dormers are often used in 1 ½ story construction to provide light and ventilation to the upper story. A gable roof consists of two shed roof structures joined at the peak forming a ridge line.
Hip A hip roof is a gable roof with angled ends taking the place of the gable end of the structure.
Dutch Hip A Dutch roof design is a hip roof with small gable ends at the ridge allowing for attic ventilation
Gambrel Gambrel roof design is similar to gable construction With two angles on each side. Steep lower surfaces and shallow angle top surfaces allow greater floor space in 1 ½ story construction
Mansard Mansard roof construction consists of a compound hip roof design with a lower and upper hip format.
Butterfly The butterfly roof is an inverted gable roof design creating a central valley for runoff. The design is visually stunning but impractical for water tightness.
Dome Geodesic Dome construction is one of the most difficult to build but is often the most interesting visually Geodesic roof construction consists of triangular framing placed together to form a dome. These structures have surprising strength and visual interest.
1. Flat roof <ul><li>A roof is designated as flat if its slope is less than ten degrees. Slope less than 3:12 or 25 percent </li></ul><ul><li>Flat roofs have traditionally been used in hot climates where water accumulation is not a problem. </li></ul><ul><li>Structural decks ordinary used </li></ul><ul><ul><li>Wood panels over wood joist </li></ul></ul><ul><ul><li>Solid wood decking over heavy timber framing </li></ul></ul><ul><ul><li>Corrugated steel decking </li></ul></ul><ul><ul><li>Sitecast concrete slab </li></ul></ul><ul><ul><li>Precast concrete slab </li></ul></ul><ul><ul><li>Panels of wood fibre bonded together with portland cement </li></ul></ul><ul><ul><li>etc </li></ul></ul>
ELEMENTS OF FLAT ROOF Concrete gutter Steel decking parapet Lines indented for expansion caused by heat and easy to flatten the roof in a uniform manner to prevent any pool of water after rain. concrete
Water pool formed due to poor workmanship PROBLEMS OF LEAKING ON FLAT ROOF
Weatherproofing the flat roof <ul><li>The flat roof relied on some kind of membrane for keeping moisture out. In dry climates this is done with clay tiles, but in Canada asphalt, or rubber is necessary. </li></ul><ul><li>Flat roofs are never actually flat, a subtle slope directs standing moisture to drains at edges, or inside. </li></ul>CONCRETE, TIMBER OR STEEL STRUCTURE Waterproof layer and insulation Cement screed Finishes
Advantages Disadvantages of Flat roof Design: <ul><li>Advantages: </li></ul><ul><ul><li>No space lost below roof, i.e. no dead space </li></ul></ul><ul><ul><li>Less material is used than in a sloped roof </li></ul></ul><ul><ul><li>The rooftop is potentially useful as a terrace, or sleeping porch </li></ul></ul><ul><ul><li>Potentially pleasing appearance </li></ul></ul><ul><ul><li>Easier to build than a sloped roof </li></ul></ul><ul><li>Disadvantages: </li></ul><ul><ul><li>Roof elements can not overlap, hence waterproofing must be more complex, and more thorough </li></ul></ul><ul><ul><li>Drainage is not automatic </li></ul></ul><ul><ul><li>Support of snow load must be insured </li></ul></ul>
Pitched Roof <ul><li> pitched roof is a roof structure where the roof leans to one side of the house. It is also known as lean-to roof. The rafters are connected to the highest wall and then it is inclined to a lower wall, which then forms the pitched roof. </li></ul><ul><li>The rafters are often connected into the wall individually or even supported on a wall plate bedded within the wall. </li></ul><ul><li>This type of roof can have no joist at all or have a tie or have a joist with a strut to give more strength. </li></ul>
column wall columns walls A mono -pitched roof structure A lean-to roof structure A pitched roof Pitched Roof Types
column wall flashing openings SUNSHADING flashing The Components
Roof Terms PITCHED ROOF TIMBER OR STEEL RAFTER Waterproofing layer and insulation Timber batten Finishes: Clay tiles or Cement tiles Metal decking Ceiling
Calculating Pitch <ul><li>Roof with a pitch of 3:12 (25 percent) or greater called Steep roof </li></ul>
<ul><li>PITCHED ROOF: TIMBER - truss </li></ul><ul><li>STEEL - truss </li></ul>Truss built as from individual members Truss fabricated from factory Truss fabricated from factory Whole roof structure built from steel Gang nails steel
rivetted Placement of roof clay tiles as seen from below
A space frame or space structure is a truss-like, lightweight rigid structure constructed from interlocking struts in a geometric pattern. Space frames usually utilize a multidirectional span, and are often used to accomplish long spans with few supports. They derive their strength from the inherent rigidity of the triangular frame; flexing loads (bending moments) are transmitted as tension and compression loads along the length of each strut. 3. Space frame
4.Dome A dome is a structural element of architecture that resembles the hollow upper half of a sphere. Dome structures made of various materials have a long architectural lineage extending into prehistory.
A thin shell is defined as a shell with a thickness which is small compared to its other dimensions and in which deformations are not large compared to thickness. A primary difference between a shell structure and a plate structure is that, in the unstressed state, the shell structure has curvature as opposed to plates structures which are flat 4. ROOF SHELL
Its an roof which has been moulded to an shape. which is in rcc, steel etc.its for large covering for open spaces 5. FOLDED PLATE ROOF
A tensile structure is a construction of elements carrying only tension and no compression or bending. The term tensile should not be confused with tensegrity, which is a structural form with both tension and compression elements. 6. Tensile structure
The CribPost System <ul><li>Main Features </li></ul><ul><ul><li>CribPosts can be extended to any desired elevation. </li></ul></ul><ul><ul><li>CribPosts can be clustered to obtain higher lifting capacities. </li></ul></ul><ul><ul><li>The roof is monitored by laser instruments to maintain close tolerances. </li></ul></ul><ul><ul><li>Lateral stability is maintained and adjusted through ROOFLIFTERS’ unique guying system. </li></ul></ul><ul><ul><li>The entire roof can be lifted in a single section using ROOFLIFTERS’ multi-point synchronization system . </li></ul></ul>The CribPost System is best described as a series of temporary hydraulic shoring posts that can be continuously extended with the intent to lift a roof to a higher elevation.
What Are Green Roofs? <ul><li>A green roof is a roof of a building that is partially or completely covered with vegetation and soil, or a growing medium, planted over a waterproofing membrane. </li></ul><ul><li>It may also include additional layers such as a root barrier and drainage and irrigation systems. </li></ul><ul><li>also known as vegetated roof covers, eco-roofs or nature roofs. water quality by filtering, absorbing or detaining rainfall. Green Roofs Are Great for These Things ,great for the environment. </li></ul>On the green roof of the Mountain Equipment Co-op store in Toronto, Canada.
Green Roof Types Green Roofs Rooftop Garden Edge Restraint Rooftop Garden Anchor Roof System Components
Rooftop Garden Edge Restraint <ul><li>A rooftop garden edge restraint that supports green roof media while allowing water to drain cleanly under paver systems on pedestal / tabs where no internal drains are present and allows water to scupper while holding back media / aggregate while serving as an independent border. </li></ul>
Roof Top Garden Anchor <ul><li>Rooftop anchors provide an efficient and economical way to secure blanket components. While conventional ties require the patience and manual dexterity of laborers, the innovation of the GRS Rooftop Anchor greatly improves effectiveness when installing rooftop mats. </li></ul>
Roof System Components <ul><li>Filter fabric, moisture retention mats, root barriers, drainage components, inspection chambers, separation fabric, media, wind erosion blankets, plants, and bio-trays. Green Roof Solutions has all of your rooftop garden and green roof systems components. </li></ul>
Green Roof Case Study Negotiated with the building owner to retrofit section of roof. Roof needed to be replaced. Environmental benefits – stormwater mitigation, building insulation, urban heat island mitigation, and aesthetic improvement. Conducted structural engineering analysis to make sure building structure could hold weight of saturated soil. The existing ballasted roof (stone) was about the same weight as the green roof. Planted with six types of sedum.
1. Insulation Layer Reused styrofoam insulation that was on roof.
2.Water Barrier <ul><li>Water Barrier is most important part of the roof, and is installed the same way as for a standard roof. </li></ul><ul><li>No Leaks! </li></ul>3.Waterproof Testing <ul><li>After waterproofing store 2 inches of water on the roof for 48 hours to test barrier. </li></ul>
4. Root Barrier <ul><li>Root barrier is thick plastic, and prevents roots from penetrating the waterproof layer. </li></ul>5. Water Retention <ul><li>Root barrier sealing and water retention layer. Water retention layer stores water in small “cups” for use by plants after rain event. </li></ul>
6. Soil Placement <ul><li>Install filter fabric beneath soil, so not to clog water retention layer. Specially engineered, highly inorganic soil (very little humus) with high water absorption capacity. </li></ul>
7. Soil Layer Spread soil to consist depth – 3 inches. 8. Wind barrier Cover soil with photo-degradable wind barrier to prevent wind erosion.
9.Planting the Roof <ul><li>Plant through the wind barrier with sedums, low-lying, hardy, water-retaining plants that thrive in harsh environments. </li></ul><ul><li>Select several varieties based on blooming, color, etc. </li></ul>
Planting Complete October 2003 One year after planting September 2004 Green Roof May 2005
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