The document discusses different types of roof structures including pitched roofs, flat roofs, space frames, roof shells, folded plate roofs, and membrane roofs. It provides details on components, materials, advantages and disadvantages of pitched and flat roofs. It also describes new concepts like the profiled steel sheet dry board (PSSDB) roof system which combines profiled steel sheeting and dryboard panels for construction.

1. Roof

2. Types of roof structure Pitch roof Flat roof Space frame Roof shell Folded plate Membrane

3. A pitched roof column wall columns walls A mono -pitched roof structure A lean-to roof structure

4. column wall column wall flashing openings SUNSHADING

5. Steep roof Roof with a pitch of 3:12 (25 percent) or greater

6. PITCHED ROOF: TIMBER - truss STEEL - truss Truss built as from individual members Truss fabricated from factory Truss fabricated from factory Whole roof structure built from steel Gang nails steel

7. rivetted Placement of roof clay tiles as seen from below

8. Roof components

9. SECTION OF ROOF STRUCTURE PITCHED ROOF TIMBER OR STEEL RAFTER Waterproofing layer and insulation Timber batten Finishes: Clay tiles or Cement tiles Metal decking Ceiling

10. STRUKTUR KAYU & KELULI Waterproofing layer Timber batten Insulation layer Finishes: Clay tiles or Cement tiles Metal decking Ceiling

12. Roof finishes – steep roof Asphalt shingles –mostly of petroleum Slate-quarried stone and concrete tiles Metal roofing materials

13. ROOF FINISHES ATTAP CLAY ROOF TILES PATTERNED STEEL DECKING 1 PATTERNED CLAY ROOF TILES PATTERNED STEEL DECKING 2 ASBESTOS

15. 2. Flat roof A roof is designated as flat if its slope is less than ten degrees. Flat roofs have traditionally been used in hot climates where water accumulation is not a problem. They were generally unkown in northern climated before the end of the last century

16. Flat roof Slope less than 3:12 or 25 percent Structural decks ordinary used Wood panels over wood joist Solid wood decking over heavy timber framing Corrugated steel decking Sitecast concrete slab Precast concrete slab Panels of wood fibre bonded together with portland cement etc

17. Flat roof The decks be adequately stiff under roof loading and uplift forces The decks must slope towards drainage points A slope at least ¼ “ per foot run (1:50) is recommended

18. Flat roof If the slope is too shallow, puddles of water will stand for extended periods Leading to premature deterioration of the roofing materials in those areas If water accumulates cause by structural deflection, progressive structural collapse becomes possibility Deepening puddles attracting more and more water and becoming heavier

19. a) Water stands on the roof in puddles, causing slight deflections of the roof deck between supporting beams or joists b)If heavy rain continues, the puddles grow and joint. Accumulating weight of the water begins to cause substantial deflections. Deflection encourage water from a border area of the roof run into the puddle c) As structural deflection increase, the depth of the puddles increases more and more rapidly, until the overloaded structure collapses a b c

20. FLAT ROOF CONCRETE, TIMBER OR STEEL STRUCTURE Waterproof layer and insulation Cement screed Finishes

21. Flat roof Thermal insulation Below the structural deck Between the deck and the membrane Above the membrane

22. Below the deck

23. Between the deck

24. Above the membrane

25. ELEMENTS OF FLAT ROOF parapet 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

26. Water pool formed due to poor workmanship

27. PROBLEMS OF LEAKING ON FLAT ROOF

28. Weatherproofing the flat roof 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. Flat roofs are never actually flat, a subtle slope directs standing moisture to drains at edges, or inside.

29. Flat roof Advantages of flat roof design: No space lost below roof, i.e. no dead space Less material is used than in a sloped roof The rooftop is potentially useful as a terrace, or sleeping porch Potentially pleasing appearance Easier to build than a sloped roof

30. Disadvantages of flat roof design: Roof elements can not overlap, hence waterproofing must be more complex, and more thorough Drainage is not automatic Support of snow load must be insured

31. Flashing Flashing is special material used to make sure that no moisture leaks in those areas of a roof that are particularly vulnerable to penetration. Areas where flashing is commonly used: Wherever the roof is pierced by a chimney, skylight, air or plumbing vent Where roofs meet walls At the edges of flat roofs where they meet parapet walls (a wall that extends above the level of the roof)

32. Flashing Materials from which flashing is made of: Galvanized metal Aluminum Copper Building paper Flashing Design: Sloped roofs: it is important to design flashing so that it throws the water downslope, and does not rely on mastic. Flat roofs: it is important that flashing be extended above the level at which you expect snow or water to accumulate

33. 3. Space frame 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.

34. Dome

35. Dome

36. 4. ROOF SHELL

38. 5. FOLDED PLATE ROOF

39. 6. MEMBRANE

40. 6. MEMBRANE

41. Roof insulation The most cost-effective Increase occupant comfort by moderating the radiant temperature of ceilings and walls Reduce heating and cooling energy Cellulose insulation- most environmentally friendly thermal insulating material Glass wool and mineral fibre Polystyrene foam made from petroleum Polyurethane foam insulation

42. New concepts of roof

45. Final products

46. PROFILED STEEL SHEET DRY BOARD ROOF SYSTEM (PSSDB) The profiled steel sheet Dryboard panel is a composite structural system consisting of profiled steel sheeting/decking compositely connected to dryboards by simple mechanical connectors .

47. Structural components of PSSDB System

48. COMPONENTS OF PSSDB AJIYA CLIP & LOCKING CL 660 --- A profiled steel sheet product of Ajiya Roofing products, Malaysia. PRIMA FLEX--- A top grade cellulose fibre, Portland cement and finely ground sand produced by Hume Cemboard Berhad, Malaysia. SCREWS --- Self-tapping, self-drilling screws.

49. Main Advantages of the System Lightweight Rapid construction Dry construction technique Easily assembled by unskilled labour Saving in foundation cost of the buildings Less deep than the traditional timber joist flooring Less loading to existing structure in renovation work No propping/formwork required during construction No waiting period for occupation after the completion of construction.

50. MAIN APPLICATIONS OF PSSDB PANEL The profiled steel sheet dryboard system can be exploited for various structural purposes such as: i) Flooring units. ii) Walling units. iii) Panels may be assembled to form Folded Plate Structures such as as roofs of buildings.

53. The normal position is not suitable to be used in real buildings. Show slight softening in strength and bulging in volume under wet condition. Even though a water proofing can be used from directly exposed to the hot and dry weather, but it is not a practical in practice Based on the original concept of the system, the application has been extended to form a new concept of roofing system. The new approach will eliminate the roof trusses normally required in traditional roof structure. PSSDB Roof system

54. Erection of roof panels

55. Erection of roof panels

56. Completed classroom modules

57. Side elevation

58. Back elevation

59. A SITE ENGINEER SENT THIS TO THE DESIGNER: S ub: High Priority Steel roof and column already constructed, kindly send us the foundation drawings. Site people can construct any thing, so please be careful with your drawings. Please send foundation drawings before superstructure drawings Regards, Site Engineer