Presentation on theme: "Thermal & Moisture Protection"— Presentation transcript:
1Thermal & Moisture Protection Arch 330Thermal & Moisture ProtectionRoofing Systems
2Roofing Systems 073000 Steep Slope Roofing Shingles and Shakes Roof TilesNatural Roof CoveringsRoofing and Siding PanelsRoof and Wall PanelsSidingMembrane RoofingFlashing & Sheet MetalRoof and Wall Specialties and Accessories
3Division 7 078000 Fire and Smoke Protection 079000 Joint Protection Joint Sealants and Expansion Control
8Name: Kallen Hawthorne ID# 10596914 Item Spotted: Flat roofObservations: This is not a good roof design for wet climates. There is constantly puddles of water on the top of this roof.Location: PEB, WSU CampusName: Kallen Hawthorne ID#
9Steep Slope drains quickly can be covered with roofing material of small overlapping units- shingles of wood- slate- artificial composition- tiles of fired clay or concrete- bundles of reeds (thatch).
10Steep Slope Thermal expansion / contraction minimized Movement in structure is minimized- by the ability of small units to move with - respect to one another.Water vapor vents from the interior through the loose joints in the roofing material.
11Name: Kallen Hawthorne ID# 10596914 Item Spotted: A combination of a flat and gamble roofObservations: This building has a very interesting skyline because of the combination roof. However if one was to look closely at the picture, one con see puddles of standing water.Location: Smith Gym, WSU CampusName: Kallen Hawthorne ID#
17Roof Slope Slope Roof to direct water towards drainage points - counter-acting structural deflection.Depending on size of deck expansion joints should be provided to- control expansion and contraction and- satisfy requirements of membrane.Membrane should be laid on flat surface.
19Deck:Types of structural deck used for low slope roof Plywood over wood joistsSolid wood decking over heavy timber framingCorrugated steel deckingPanels of wood fiber bonded together with portland cementPoured gypsum over insulating formboardSitecast concrete and precast concrete
22Insulating Deck Boards – wood/glass fibers Truss Tee Purlins + slab of gypsum/lt wt conc
23Thermal Insulation Below the Deck Between Deck + Membrane Above the Membrane
24Thermal Insulation: Below the Deck Leaves the deck and membrane exposed to full range of temperature.Batt insulation of glass fiber or mineral fiber between wood joists- or on top of a suspended ceiling assembly.Vapor retarder below insulation**(Vapor retarder on warm side of insulation)
25Insulation: Between Deck and Membrane Rigid panels of insulation, light weight concrete.Protects deck from temperature extremes.Membrane subjected to extreme temperature variations.Moisture trapped in insulation can damage insulation and deck.Place vapor retarded on inside of insulation and vent insulation to release moisture.
26Insulation: Above the Membrane Membrane protected - extremes of temperature.Membrane on warm side of insulation - immune to vapor blistering.Insulation must be a material which is not effected by wet and will not disintegrate - extruded polystyrene boardInsulation board adhered in bed of hot asphalt or laid loose.Layer of ballast laid over insulation.
27Insulation: Above the Membrane Ballast- crushed stone- thin concrete layer factory laminated to upper surface of insulation board- interlocking concrete blocks.Membrane ages little protected from sunlight and temperature extremes - despite presence of moisture.Rigid insulation - mechanical fix to deck preferable.
28Insulation above the Membrane: Other names for this system Inverted roofUpside down roofProtected membrane roof,+- 20years old
29Vapor Retarder 2 sheets asphalt saturated roofing felt In cold climate on warm side of insulation.**In hot humid climate/with air conditioning - on outer side of insulation**
30Membrane Built up roof membrane Single-ply roof membrane Fluid-applied roof membrane
31Built-up membrane 2-4 Layers/ plies of felt asphalt impregnated, bedded in bitumenfelt: cellulose fibers/glass fibers +asphaltFelt laminated in overlapping layersLayer of aggregate (crushed stone)
32Built-Up Membrane Bitumen - asphalt derived For low pitch roofs - coal tar bitumen or coal-tar pitch used-- greater resistance to standing waterAsphalt and coal tar are applied hot
33AggregateInsulationFeltConc. DeckInsulation x 2Metal Deck
40Built-Up + Single Ply Ballast loose stone aggregateprecast concrete blocks.Ballast holds the membrane in place against wind upliftProtects membrane from ultraviolet light and physical wear.Increase the fire resistance of the roof covering.
41Traffic Decks-walks, terraces, parking – on low slope roof Heavy square paving slabs or stones –open jointson blocks of plastic or conc on roof membrane(b) Open Jointed Paving Blocks on A drainage layer of gravel or porous concrete leveled over the membraneWater falls through the joints and is drained away by the membrane belowMembrane is not pierced.
42Structural Standing Seam Metal Roofing for Low Slope Roofs: Proprietary systems of standing seam metal roofingUsed as low slope roofs - 1/4" in 12 "(1:48).The folded shape - stiffness - support itself + a normal snow load between purlins without the need for structural deck below.
57Steep Slope >3:12 pitch Drains quickly,Small overlapping units - ShinglesExpansion and contraction and movementWater vapor vents
58Steep Slope Roof – Systems 3 Categories of Covering ThatchShingles – wood, asphalt, slate, clay/concSheet Metal – lead, copper, terne, aluminum
59Steep Sloped Roof Systems Typically insulation and vapor retarder installed below the roof sheeting or deck.Underside of deck is exposed as a finished surface- vapor retarder and rigid insulation above the deck below roofing layer of plywood (nailed over the insulation panels as a nail base for fastening shingles or sheet metal).
60InsulationSteep Sloped RoofTypically insulation and vapor retarder installed below the roof sheeting or deck.
61InsulationSteep Sloped RoofUnderside of deck is exposed as a finished surface
65ShinglesSmall size unit, applied to roof in overlapping layers - staggered vertical jointswood shingles/ shakesasphalt shinglesslatesclay tiles and concrete tiles.PV – photovoltaic
66ShinglesEach type of shingle, slate or tile must be laid on a roof deck - that slopes sufficiently to assure leak-proof performance.Min. slope for each material are specified by the manufacturer and code
67Wood Shingles:Thin, tapered slabs of wood, SAWED from short pieces of tree trunkGrain parallel to the face of the shingle.
70Wood Shakes Split not sawn Rough face texture, North US - wood shingles/ shakes are Red cedar, White cedar,Redwood - natural decay resistance.Wood roof covering moderately expensive, not highly resistant to fire unless pressure treated with fire retardant chemicals.
72Asphalt ShinglesAsphalt impregnated felt - faced with mineral granules.Die cut from sheet, typical size 12" x 36".Slotted twice - smaller unit.Inexpensive, quick to install, moderately fire resistant.Expected life time of 15 to 25 years.Laid on asphalt saturated felt paper in two layers.
87Architectural Sheet Metal Roofing: Relatively high in first costLast for many decades.Galvanic action should be avoided in the roof installation.Beware of water run-off also re galvanic action from one metal to another.
94Lead, Copper: Sheet Used since ancient times. Self-protecting metal - last many decades.Installed in sheets using systems of joining and fasteningMaintain water tightness at the seams.Seams especially standing & batten seams create a strong visual pattern.
95Lead, Copper: Sheet Lead oxidizes to a white color. Copper turns blue-green in clear air, black in an industrial atmosphere.Chemical treatments and coatings can be applied to preserve a desired color.
96Other Sheet Metals Aluminum, Zinc Alloys, Stainless Steel Sheet Metal RoofingCan be used in same way as copper, lead and terne