Building Systems Design Lecture Notes PDF

EVOLUTION  The first building envelope that protected humans from the elements was probably a cave that provided a degree of privacy and security.  The earliest building envelopes were dome-shaped structures that combined wall and roof.  At an early stage, the two dominant forms of envelop...

EVOLUTION  The first building envelope that protected humans from the elements was probably a cave that provided a degree of privacy and security.  The earliest building envelopes were dome-shaped structures that combined wall and roof.  At an early stage, the two dominant forms of envelope evolved were the timber frame and the masonry wall.  Eventually the roof, wall, and floor become distinct elements of the building envelope. EVOLUTION  The real beginning of today's concept of the building envelope occurred with the invention of the steel frame in the nineteenth century.  However, for several decades the steel frame was buried in masonry walls, and buildings continued to be designed in Gothic or Renaissance styles.  Modern architectural revolution begun in the early 20th century and by mid-century the steel or concrete frame office building with its lightweight metal and glass curtain wall had become the new world- wide vernacular for larger commercial and institutional buildings. EVOLUTION EVOLUTION EVOLUTION FUNCTION AND PERFORMANCE FOUR FUNCTION CATEGORIES 1. Structural Support Function — to support, resist, transfer and otherwise accommodate all the structural forms of loading imposed by the interior and exterior environments, by the enclosure and by the building itself 2. Environmental Control Function — to control, regulate and/or moderate all the loadings due to the separation of the interior and exterior environments; largely the flow of mass and energy. FUNCTION AND PERFORMANCE FOUR FUNCTION CATEGORIES 3. Finish Functions — the interfaces of the enclosure within the interior and exterior environments. Each of the interfaces must meet the relevant visual, aesthetic, wear and other requirements. 4. Distribution Function — the distribute services or utilities such as power, communication, security, water in its forms, gas and air-conditioned air to, from and within the enclosure itself. FUNCTION AND PERFORMANCE DISTINCT FUNCTIONS 1. Structural – if the wall is not part of the main structure, support own weight and transfer lateral loads to building frame. 2. Water – resist water penetration. 3. Air – resist excessive air infiltration. 4. Condensation – resist condensation on interior surfaces under service conditions. 5. Movement – accommodate differential movement caused by moisture, seasonal or diurnal temperature variations, and structural movement. FUNCTION AND PERFORMANCE DISTINCT FUNCTIONS 6. Energy conservation – resist thermal transfer through radiation, convection and conduction. 7. Sound – attenuate sound transmission. 8. Fire Safety – provide rated resistance to heat and smoke. 9. Security – protects occupants from outside threats. 10. Maintainability – allows access to components for maintenance, restoration and replacement. FUNCTION AND PERFORMANCE DISTINCT FUNCTIONS 11. Constructability – provide adequate clearance, alignments, and sequencing to allow integration of many components during construction using available components and attainable workmanship 12. Durability – provide functional and aesthetic characteristics for a long time. FUNCTION AND PERFORMANCE PERFORMANCE Performance refers to the desired level (or standard) to which the system must be designed for each of the functional requirements. The following performance issues are examined for each of the envelope systems:  Major Performance Issues  Specialized Building Performance Issues FUNCTION AND PERFORMANCE MAJOR PERFORMANCE ISSUES  Thermal performance  Moisture protection  Fire safety  Acoustics  Daylight and perimeter visual environment  System maintainability  Material durability FUNCTION AND PERFORMANCE SPECIALIZED BUILDING PERFORMANCE ISSUES  Seismic safety  Safety against blast and chemical, biological and radiological (CBR) attack  Safety against extreme wind  Indoor air quality and mold prevention  Sustainability and HVAC integration I. BELOW GRADE SYSTEM Below Grade is an area that is below ground level usually referred to as basement. These below grade areas provide functional spaces for uses such as:  storage,  office space,  mechanical/electrical rooms,  parking, tunnels,  crawlspaces, etc. I. BELOW GRADE SYSTEM THREE MAIN ELEMENTS A. Foundation Walls B. Slabs on Grade C. Plaza Decks The success of the below grade building is largely dependent on the ability to control moisture. I. BELOW GRADE SYSTEM Foundation Walls I. BELOW GRADE SYSTEM A. FOUNDATION WALLS Materials common in foundation walls and below grade building enclosure systems in general are as follows: 1. Drainage Materials 5. Protection Board 2. Filter Fabrics 6. Insulation Materials 3. Damp-proofing 7. Waterstops 4. Waterproofing Membranes 8. Drainage Pipes I. BELOW GRADE SYSTEM Foundation Walls I. BELOW GRADE SYSTEM Foundation Walls I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 1. Drainage Materials a. Aggregate Drainage Layer — includes graded pea-gravel aggregate or coarse sand. b. Prefabricated Synthetic Drainage Layer — consist of a combination of plastic composite drainage cores with adhered geotextile fabrics. I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 2. Filter Fabrics — geotextile filter fabrics are also used for separating different soil types in below grade enclosure applications. I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 3. Damp-proofing— intended to control vapor diffusion through the foundation, which can contribute to damp conditions on the interior.  Are often bitumen-based coatings: typically applied up to 0.25mm in thickness. These materials can be solvent based or water emulsion. I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 4. Waterproofing Membranes —can either post-applied or pre- applied products for use in either positive side, negative side, or blind-side applications.  Positive-side waterproofing systems  Negative-side waterproofing systems  Blind-side waterproofing systems I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 4. Waterproofing Membranes  Positive-side waterproofing systems are post-applied to the surface of the element that is directly exposed to moisture (typically the exterior side of the foundation wall).  Negative-side waterproofing systems are post-applied to the surface of the element opposite the surface exposed to moisture (typically the interior side or the foundation wall).  Blind-side waterproofing systems are pre-applied to the area where the concrete element will be placed that is directly exposed to moisture I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 4. Waterproofing Membranes Four Types: a. Fluid-Applied Systems — includes urethanes, rubbers, plastics, and modified asphalts b. Sheet-Membrane Systems — includes thermoplastics, vulcanizing rubbers, and rubberized asphalts c. Bentonite Clays — includes composite sodium bentonite systems with HDPE liners and geotextile fabrics d. Cementitious Systems — contains Portland cement and sand combined with an active waterproofing agent I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 5. Protection Board — used to shield waterproofing membranes from construction damage from backfill materials in service and ultraviolet radiation. a. Most commonly used protection board is a semi-flexible sheet containing an asphalt core placed between asphalt impregnated glass fiber mats. I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 5. Protection Board I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 6. Insulation Materials — are primarily limited to rigid extruded polystyrene board due to the need for high compressive strength and moisture absorption resistance. I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 7. Waterstops — should be utilized at construction joints in below grade walls, footing slabs, and other elements where a waterproofing system is required. It provides a secondary barrier to the passage of water across these construction joints. a. Common materials include polyvinyl chloride (PVC), neoprene, expanding sodium bentonite and thermoplastic rubber. I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 7. Waterstops I. BELOW GRADE SYSTEM A. FOUNDATION WALLS 8. Drainage Pipe — typically 4" or in diameter primarily made of corrugated PVC or polyethylene and In some cases or porous concrete. I. BELOW GRADE SYSTEM B. SLAB ON GRADE Materials common in floor slab systems are as follows: 1. Finish floor covering 2. Concrete floor slab 3. Under slab vapor retarder or waterproofing membrane 4. Capillary break layer I. BELOW GRADE SYSTEM B. SLAB ON GRADE Materials common in floor slab systems are as follows: 1. Finish floor covering – may be the exposed concrete surface itself or various floor covering such as wood, vinyl floors, or carpet I. BELOW GRADE SYSTEM B. SLAB ON GRADE Materials common in floor slab systems are as follows: 2. Concrete floor slab – comprised of 4” to 6” thick concrete with one layer of welded wire fabric at mid depth I. BELOW GRADE SYSTEM B. SLAB ON GRADE Materials common in floor slab systems are as follows: 3. Under slab vapor retarder or waterproofing membrane – may include polyethylene sheets, polyolefin sheets, high density bonded polyethylene, and asphalt/polyethylene composite sheet or polymer modified bitumen sheets - Waterproofing on the slabs is necessary to resist hydrostatic pressures I. BELOW GRADE SYSTEM B. SLAB ON GRADE Materials common in floor slab systems are as follows: 4. Capillary break layer – typically comprised of 6” to 8” thick layer ¾” granular materials that is gap graded to increase drainage rate - The granular material serves as a capillary break and a place to store water so it can be absorbed back into the surrounding soil I. BELOW GRADE SYSTEM C. PLAZA DECK A plaza deck is any supported slab that provides green-scape, tree planters, and/or vehicle and pedestrian movement over occupied space. Basic components of a plaza deck system: 1. Wearing surface 2. Fill slab 3. Isolation layer/drainage layers and flow path system 4. Membrane and protection layer 5. Structural support systems I. BELOW GRADE SYSTEM C. PLAZA DECK I. BELOW GRADE SYSTEM C. PLAZA DECK I. BELOW GRADE SYSTEM C. PLAZA DECK Basic components of a plaza deck system: 1. Wearing surface – any surface subjected to pedestrian or vehicular traffic. Concrete, brick pavers, asphalt paving blocks, and/or pre-cast elements are all common plaza deck wearing surface systems. I. BELOW GRADE SYSTEM C. PLAZA DECK Basic components of a plaza deck system: 2. Fill slab – anything that occupies space on the plaza deck above the membrane and below the wearing surface.  Graded sand asphalt materials, pea gravel or a sand-cement mortar setting bed is used. More recently, extruded or expanded polystyrene insulation, loose earth or lightweight concrete are used on horizontal applications of plaza deck to fill these layers. I. BELOW GRADE SYSTEM C. PLAZA DECK Basic components of a plaza deck system: 3. Isolation layer/drainage layers and flow path system – consist of pea gravel and/or separator fabric over pea gravel - Common for isolation components consists of a combination of geo-synthetic materials and pea stone drainage fill I. BELOW GRADE SYSTEM C. PLAZA DECK Basic components of a plaza deck system: 4. Membrane and protection layer – includes a special waterproofing membrane to prevent moisture leakage into the occupied space below.  Insulation can also be provided directly on the top of the membrane and protection layer to promote long term system durability. I. BELOW GRADE SYSTEM C. PLAZA DECK Basic components of a plaza deck system: 5. Structural support systems – any of the basic slab design. It can be two-way flat plate slab, one-way slab on beam, post- tensional slab-beam system, or precast system. II. WALL SYSTEMS An exterior wall typically forms part of a building envelope, separating the accommodation inside from that outside. Basic Elements or Layers of an Exterior Wall 1. Exterior Cladding (Natural or Synthetic) 2. Drainage Planes 3. Air Barrier Systems 4. Vapor Retarder 5. Insulating Elements 6. Structural Elements II. WALL SYSTEMS Basic Elements or Layers of an Exterior Wall 1. Exterior Cladding (Natural or Synthetic) — it is the protective layer or finish affixed to the exterior side of a building enclosure 2. Drainage Planes — any element exposed to weather or otherwise residing at the line between the "wet" and "dry" zones of an exterior wall system or assembly. II. WALL SYSTEMS Basic Elements or Layers of an Exterior Wall 3. Air Barrier Systems — any element, or combination of elements, that is intended, by design to control the movement of air across an exterior wall system. 4. Vapor Retarder — any element that is intended to control or otherwise limit the flow of water in its vapor form across and exterior wall system. II. WALL SYSTEMS Basic Elements or Layers of an Exterior Wall 5. Insulating Elements — any element, or combination of elements, that IS intended to control or otherwise regulate heat loss and heat gain across an exterior wall system 6. Structural Elements — any element, or combination of elements, in an exterior wall system that is intended to effectively resist both live and dead loads acting on a building or structure through the efficient and effective distribution of those loads to the underlying structural frames II. WALL SYSTEMS Cast-in-Place Concrete - generally defined by the building's structural system, which consists of the vertical (gravity) load resistant system and the lateral (wind and seismic) resistant system II. WALL SYSTEMS Exterior Insulation and Finish System (EIFS) a. An exterior wall cladding that utilizes rigid insulation boards on the exterior of the wall sheathing with a plaster appearance exterior skin. b. The most common type of EIFS is the polymer based (PB) system and less common type is the polymer modified system. c. IEFS can be a barrier system or wall drainage system. II. WALL SYSTEMS Exterior Insulation and Finish System (EIFS) II. WALL SYSTEMS Masonry Wall System II. WALL SYSTEMS Masonry Wall System a. Can be used to form a durable cladding and to achieve various aesthetic effects. b. It can also serve as a portion of a structural framing for the building. c. Typically increases the fire resistance of the wall system or structural elements. d. Several different types of masonry units are commonly used. e. Common masonry unit types include clay and concrete units, which may be solid or hollow, and glazed or unglazed. Other masonry unit types include cast stone and calcium silicate units. II. WALL SYSTEMS Panelized Metal Wall System II. WALL SYSTEMS Panelized Metal Wall System Metal panels can be aluminum, stainless steel, copper or steel. Aluminum is the most common material used due to its cost, corrosion resistance, and durability. In high-end applications, stainless steel and copper can also be used. Several manufacturers fabricate steel panel systems, which require protective coatings for resistance to corrosion. Types of metal panel system: 1. Lap-Seam Metal Panel 2. Composite Metal Wall Panels 3. Flat Plate Metal Wall 4. Metal-Faced Composite Panels II. WALL SYSTEMS Panelized Metal Wall System Types of metal panel system: 1. Lap-Seam Metal Panel — are formed out of metal sheets and are typically ship-lapped with adjacent panels. II. WALL SYSTEMS Panelized Metal Wall System Types of metal panel system: 2. Composite Metal Wall Panels — feature two sheets of metal adhered to a core material. These composite panels are usually stronger than lap-seam panels and provide built-in insulation to the wall system. II. WALL SYSTEMS Panelized Metal Wall System Types of metal panel system: 3. Flat Plate Metal Wall Panels — typically fabricated out of 1/8-inch- thick metal plate. Since these panels are manufactured out of plates they have very high impact resistance and durability compared to other types of panels. II. WALL SYSTEMS Panelized Metal Wall System Types of metal panel system: 4. Metal-Faced Composite Panels — consist of metal facings adhered to a thin thermoplastic core. II. WALL SYSTEMS Pre-cast Wall System II. WALL SYSTEMS Pre-cast Wall System Offer a wide variety of shapes, colors, textures, and finishes to the designer. Typically, each pre-cast panel is independently supported to the building structure using an assemblage of metal components and anchors. Joints around each of the precast panels are usually filled with sealant. In some cases, pre-cast panels are used as formwork for cast-in- place concrete. The pre-cast panels act as a form providing the visible aesthetics of the system, while the cast-in-place portion provides the structural component of the system. II. WALL SYSTEMS Pre-cast Wall System Types of Pre-cast Panel: 1. Cladding or Curtain Walls - are the most common use of pre-cast concrete for building envelope. They are only designed to resist wind, seismic forces generated by their own weight, and forces required to transfer the weight of the panel to the support. II. WALL SYSTEMS Pre-cast Wall System Types of Pre-cast Panel: 2. Load-bearing wall units — resist and transfer loads from other elements and cannot be removed without affecting the strength or stability of the building. II. WALL SYSTEMS Pre-cast Wall System Types of Pre-cast Panel: 3. Pre-cast concrete shear wall panels —used to provide lateral load resisting system when combined with diaphragm action of the floor construction. II. WALL SYSTEMS Thin Stone Wall System Typically consist of stone panels ranging in thickness from 3/4 inches to 2 inches. Most panels are fabricated from granite, white marble; limestone, travertine, and sandstone are also used to a lesser extent. III. FENESTRATION SYSTEMS Fenestration refers to the openings in the building envelope, including the installation of windows, doors, and skylights. Components: A. Curtain Wall B. Exterior Doors C. Glazing D. Sloped Glazing E. Window III. FENESTRATION SYSTEMS COMPONENTS A. Curtain Wall Thin, usually aluminum-framed wall, containing in-fills of glass, metal panels, or thin stone. Commonly used curtain wall framing methods: a. Method of Fabrication b. Moisture Protection III. FENESTRATION SYSTEMS COMPONENTS A. Curtain Wall a. Method of Fabrication 1. Stick Systems — the curtain wall frame (mullions) and glass or opaque panels are installed and connected together piece by piece, 2. Unitized or Modular Systems - the curtain wall is composed of large units that are assembled and glazed in the factory, shipped to the site and erected on the building. III. FENESTRATION SYSTEMS COMPONENTS A. Curtain Wall b. Moisture Protection 1. Water-managed —no effort is made to create an air barrier on each glass or spandrel unit, and therefore a larger amount of water is forced into the system and must be wiped away. 2. Pressure-equalizer —functions by blocking all of the forces that can drive water across a barrier. III. FENESTRATION SYSTEMS COMPONENTS B. Exterior Doors  Entrance and exit doors generally serve as building entrances for the general public or as service entrances for building operations personnel.  Commonly used door materials include aluminum, steel, wood and glass.  Doors that are integrated with commercial storefronts are typically aluminum frames with glass in-fills, or all glass. III. FENESTRATION SYSTEMS COMPONENTS B. Exterior Doors Common door type: Swing doors, generally serving Entrance/Exit functions. III. FENESTRATION SYSTEMS COMPONENTS B. Exterior Doors Common door type: Revolving doors, generally serving Entrance/Exit functions. III. FENESTRATION SYSTEMS COMPONENTS B. Exterior Doors Common door type: Industrial (e.g. overhead) doors, selling material handling and security functions. III. FENESTRATION SYSTEMS COMPONENTS C. Glazing Glass has been used for thousands of years to allow daylight into our buildings, while providing weather protection. Commonly used glass and glazing components: 1. Annealed glass 2. Heat-strengthened glass 3. Fully-tempered glass 4. Laminated glass 5. Coated glass 6. Tinted glass 7. Insulating glass units III. FENESTRATION SYSTEMS COMPONENTS C. Glazing Commonly used glass and glazing components: 1. Annealed glass —most commonly used architectural glass adhere together with plastic interlayer. Often used as safety glazing and overhead glazing skylights. III. FENESTRATION SYSTEMS COMPONENTS C. Glazing Commonly used glass and glazing components: 2. Heat-strengthened glass — twice the strength and resistance to breakage from wind loads or thermal stress as annealed glass. III. FENESTRATION SYSTEMS III. FENESTRATION SYSTEMS COMPONENTS C. Glazing Commonly used glass and glazing components: 3. Fully-tempered glass — provides at least four times the strength of annealed glass, give superior resistance to breakage. III. FENESTRATION SYSTEMS III. FENESTRATION SYSTEMS COMPONENTS C. Glazing Commonly used glass and glazing components: 4. Laminated glass — consist of two or more lites of glass glazing in skylights. III. FENESTRATION SYSTEMS 4. Laminated glass — consist of two or more lites of glass glazing in skylights. III. FENESTRATION SYSTEMS COMPONENTS C. Glazing Commonly used glass and glazing components: 5. Coated glass — covered with reflective or low-emissivity coating. It can improve the thermal performance of the glass by reflecting visible light and infrared radiation. III. FENESTRATION SYSTEMS 5. Coated glass III. FENESTRATION SYSTEMS COMPONENTS C. Glazing Commonly used glass and glazing components: 6. Tinted glass — contains minerals that color the glass uniformly through its thickness and promote absorption of visible light and infrared radiation. III. FENESTRATION SYSTEMS 6. Tinted glass III. FENESTRATION SYSTEMS COMPONENTS C. Glazing Commonly used glass and glazing components: 7. Insulating glass units (IG units) consists of two or more lites of glass with a continuous spacer that encloses a sealed air space. Most commercial windows, curtain walls and skylights contain IG units. III. FENESTRATION SYSTEMS COMPONENTS D. Sloped Glazing – skylights have been used for over a century to provide interior daylighting Typical skylight components: 1. Supporting members 2. Infill panels III. FENESTRATION SYSTEMS COMPONENTS D. Sloped Glazing III. FENESTRATION SYSTEMS COMPONENTS D. Sloped Glazing Typical skylight components: 1. Supporting members — rafters spanning from sill to ridge, cross bars between the rafters, and pressure bars that that clamp the edges of the glass to the rafters. The pressure bars are frequently covered by rafter caps to conceal the fastener heads and shield them from rainwater. III. FENESTRATION SYSTEMS COMPONENTS D. Sloped Glazing Typical skylight components: 2. Infill panels — generally glass but also proprietary translucent products, such as fiberglass sheets or fiberglass sandwich panels. III. FENESTRATION SYSTEMS COMPONENTS E. WINDOW  Commonly used window frame materials include aluminum, vinyl, fiberglass, steel wood, and PVC.  Aluminum frames are the most widely used window frame material, and provide design flexibility because of the wide range of available stock systems and the relative economy of creating custom extensions. III. FENESTRATION SYSTEMS COMPONENTS E. WINDOW  Wood, vinyl and fiberglass are the most widely used window frames in the residential market.  Commonly used window and frame options:  Window units can be fixed, operable or combination of the two. III. FENESTRATION SYSTEMS COMPONENTS E. WINDOW Operable windows can be classified as: 1. sliding seal windows or 2. compressional seal windows III. FENESTRATION SYSTEMS COMPONENTS E. WINDOW Operable windows 1. Sliding seal window types  Hung windows  Horizontal sliding windows III. FENESTRATION SYSTEMS COMPONENTS E. WINDOW Operable windows 2. Compression seal windows include the following:  Awning (Top hinged, project out bottom)  Hopper (Bottom project in top)  Casement (Side hinged, project in or out)  Vertically or horizontally pivoted windows Pivot windows, jal-awning, and jalousie windows generally offer the poorest resistance III. FENESTRATION SYSTEMS COMPONENTS E. WINDOW Operable windows 2. Compression seal windows include the following:  Awning (Top hinged, project out bottom) III. FENESTRATION SYSTEMS COMPONENTS E. WINDOW Operable windows 2. Compression seal windows include the following:  Hopper (Bottom project in top) III. FENESTRATION SYSTEMS COMPONENTS E. WINDOW Operable windows 2. Compression seal windows include the following:  Casement (Side hinged, project in or out) III. FENESTRATION SYSTEMS COMPONENTS E. WINDOW Operable windows 2. Compression seal windows include the following:  Vertically or horizontally pivoted windows Pivot windows, jal-awning, and jalousie windows generally offer the poorest resistance IV. ROOF SYSTEMS Roofs are fundamental in protecting buildings from moisture infiltration and other outside weather conditions. Commercial buildings typically use low-slope or flat roofs, and the choice of roofing material affects issues regarding moisture, standing water, durability and appearance. Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) B. Steep-slope Roof Coverings C. Roof Deck IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 1. Built-up Roofs (BUR) — composed of alternating layer of bitumen and reinforcement sheets IV. ROOF SYSTEMS IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 2. Mesh Reinforced Elastomeric Coatings (MREC) — composed typically of acrylic elastomeric and polyester reinforcing mat applied in multiple layers for a final dry film. IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 3. Modified Bitumen (MB) - they are typically composed of pre- fabricated polymer-modified asphalt sheets with a reinforcement layer. a. Atactic Polypropylene (APP) - APP polymer is blended With asphalt and fillers. b. Styrene-Butadiene-Styrene (SBS) — SBS polymer is blended with asphalt and fillers. c. Styrene-Ethylene-Styrene (SEBS) — SEBS is blended to asphalt. IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 3. Modified Bitumen (MB) IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 4. Single-ply Thermoplastic Single-Plies — these sheets are normally around 5 to 12 feet wide 11.5 to 3.6 ml. Some manufacturers weld the sheets together in the factory to form large sheets that are then welded together on the roof.  Polyvinyl Chloride (PVC)  Thermoplastic Polyolefin (TPO)  Ketone Ethylene Ester (KEE) IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 4. Single-ply Thermoplastic Single-Plies IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 4. Single-ply Thermoplastic Single-Plies  Polyvinyl Chloride (PVC) — are resistant to animal fats and grease and are a good choice for roofs with kitchen exhausts. IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 4. Single-ply Thermoplastic Single-Plies  Thermoplastic Polyolefin (TPO) — TPO membrane do not rely upon plasticizers for flexibility, so embrittlement due to plasticizer loss is of no concern. TPO membranes are typically white, and are available in sheet widths up to 3.6m. IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 4. Single-ply Thermoplastic Single-Plies  Ketone Ethylene Ester (KEE) — this membrane is also referred to as a tripolymer alloy (TPA). KEE sheets are similar to PVC. IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 5. Thermoset Single-Plies — are normally cross-link during manufacturing. Once cured, these materials can only be bonded together with a bonding adhesive or specially formulated tape.  Ethylene Polypropylene Diene Monomer (FPDM) IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 5. Thermoset Single-Plies Ethylene Polypropylene Diene Monomer (FPDM) — EPDM membranes are extremely resistant to weathering and they have very good low-temperature flexibility. They are suitable at airport buildings, provided liquid fuel is not spilled on the membrane. IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 5. Thermoset Single-Plies Ethylene Polypropylene Diene Monomer (FPDM) IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 6. Sprayed Polyurethane Foam (SPF) — SPF is a very unique type of roof system. The membrane is constructed by spraying a two-part liquid onto a substrate. The mixture expands and solidifies to form closed-cell polyurethane foam. IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 7. Metal Panels — metal panels are not typically thought of as options for low-slope roofs. Some metal panel systems, however, can be used on very low-slopes. IV. ROOF SYSTEMS Materials for Roof System: A. Low-slope Roof Coverings Built-up Roofs (BUR) 8. Hot and Cold fluid-applied roofing membranes — more widely known to be used as waterproofing systems but have gained in popularity as roof systems. IV. ROOF SYSTEMS Materials for Roof System: B. Steep-slope Roof Coverings Roofing Shingle IV. ROOF SYSTEMS Materials for Roof System: B. Steep-slope Roof Coverings Roofing Shingle - is applicable to a wide variety of roofing materials including asphalt, metal, wood, clay and slate. While the roofing material may vary, roofing shingles are generally installed following the same guidelines, such as the fact that they can only be installed on buildings pitched (aka sloped) roofs.  Metal Panels and Shingles  Asphalt, Wood, and Synthetic Shingles  Wood Shakes  Clay and Concrete Tile IV. ROOF SYSTEMS Materials for Roof System: B. Steep-slope Roof Coverings Roofing Shingle  Metal Panels and Shingles - Metal roofing is another broad term that refers to roofing products composed of various types of metal, including, aluminum roofing, standing seam roofing, corrugated roofing, copper roofing, and stone-coated steel roofing. IV. ROOF SYSTEMS Materials for Roof System: B. Steep-slope Roof Coverings Roofing Shingle  Asphalt, Wood, and Synthetic Shingles - shingles are available with either fiberglass or organic reinforcement. Fiberglass-reinforced shingles provide greater fire resistance and are therefore recommended. IV. ROOF SYSTEMS Materials for Roof System: B. Steep-slope Roof Coverings Roofing Shingle  Wood Shakes — natural slates have the potential to offer several decades of service life. However, slate is heavy and very expensive. IV. ROOF SYSTEMS Materials for Roof System: B. Steep-slope Roof Coverings Roofing Shingle  Clay and Concrete Tile - tiles can either be made from clay or concrete. Tiles typically can be expected to offer a longer service life than asphalt shingles. However, tiles are heavy and more costly than shingles. IV. ROOF SYSTEMS Materials for Roof System: B. Steep-slope Roof Coverings Roofing Shingle  Clay and Concrete Tile IV. ROOF SYSTEMS C. Roof Decks Commercial and institutional buildings typically have steel or concrete roof decks, although plywood or Oriented Strand Board (OSB) decks are also used on smaller buildings. V. ATRIA SYSTEM  Atria - a term for an interior court in Roman domestic architecture and also a type of entrance court in early Christian churches.  Today atrium means an enclosed multi-storied space that is open vertically to multiple stories. V. ATRIA SYSTEM