Exam Prep Module 6-10 PDF

Module 6 1. Types & terminology. 2. Slopes. 3. Roof Framing: Ceiling Joists and Rafters. Intermediate Support. 4. Sizing Ceiling, Rafter, and Roof Joists. In-class Exer...

Module 6 1. Types & terminology. 2. Slopes. 3. Roof Framing: Ceiling Joists and Rafters. Intermediate Support. 4. Sizing Ceiling, Rafter, and Roof Joists. In-class Exercise 1. 5. Roof Trusses: Terminology. Framing. 6. Roof Rakes / Ladders / Lookouts. 7. Flat Roofs. 8. Roof Sheathing. 9. Eaves, Soffits and Fascias. 10. Chimneys. Two ways to frame a roof: 1. Conventional Dimensional Wood/Stick 2. Framing.Roof trusses / Pre-engineered framing. Roof Rafters If the rafters are supported on a structural ridge beam, ceiling joists are not required to absorb the lateral thrust. This roof system is called a vaulted, or cathedral ceiling. When roof and ceiling finishes are applied directly to the roof joists, the roof joists must be sized to accommodate minimum insulation and ventilation OBC Supplementary Standard SB-12 requirements for energy efficiency for housing  Roof Framing - Sizing Ceiling Joists & Roof Rafters 1. Must always be done together. 2. Choose either the rafter span OR the ceiling joist span. 3. Ceiling Joists - Table A-3. 4. Roof Rafters - Tables A-6 & A-7. 5. Remember Snow Loads! Roof Framing - Sizing Roof Joists 1. Determine span. 2. Roof Joists - Table A-4 & A-5. 3. Remember Snow Loads! Roof Trusses Prefabricated wood trusses are commonly used in buildings where roof spans are large. Prefabrication reduces on-site labor and makes trusses a popular alternative in regions with unfavorable weather conditions or high labor costs. As wood trusses are made from thin 2x members and connected with sheet steel nailing plates, they must be handled carefully during hoisting or placing in position so that the nailing plates do not open up.  Prefabricated structural frames. A wide variety of shapes, designs and sizes are possible. Girder Trusses A girder truss spans the roof and is designed to carry a higher load than other trusses in the same construction. Gable roof truss systems A standard gable is the simplest arrangement with gable end trusses at both ends and common trusses in between, gable end trusses sit on the end walls to carry roof loads directly into the wall below. Common trusses are designed to act as bending member spanning between the walls. Trusses uplift – solution is to allow for movement in ceiling finish OBC REFERENCES 9.23.13. Roof and Ceiling Framing 9.23.15. Roof Sheathing Module 7 1. Floor Framing Systems: Balloon Framing. Platform Framing. 1. Anchorage Systems. 2. Major Components: Header / Rim Joists. Headers and Trimmers. Tail Joists. Cantilevered Floors. Bridging, Strapping and Blocking. 1. Notching and Drilling Floor Joists. 2. Loads. 3. Sizing. 4. In-class Exercise 1. 5. Subfloors. Wood Frame Systems - Evolution Light frame construction systems have evolved over nearly two centuries and has been adapted to several technical innovations in buildings, such as insulation, electricity, piped water supply and sewage disposal. The systems adaptability and the ease with which it could be used led to it’s success and popularity. Wood Frame Systems - Balloon Framing Wood frame construction replaced heavy, load bearing construction. Called Balloon framing. Consisted of thin, closely spaced, vertical wood members called studs and similar floor and roof framing members called joists and rafters. Platform framing Evolved from balloon framing. Where a floor system (platform) is used to construct load bearing walls to support the subsequent floor system Anchorage Systems The transitioning member between the concrete foundation and the wood frame above is the sill plate (mud sill): Provides bearing support. Provides a level surface to support wood framing. Anchorage for the structure. Fitting sills to the foundation Fills gaps between the foundation and the sill with grout so that the sill will have full bearing support to the weight of the house. Floor Framing What influences floor performance? Joist depth. Joist spacing. Span. Direct applied ceiling. Bridging, strapping and blocking. Walls – bearing and partitions. Supported by walls or beams. Subfloor – type and thickness. Glued of nailed decking. Tail Joists Joists which are not continuous over a span. Joists that end at a header. Cantilevered Floors Floor joists that extend beyond their support. Cantilevered joists may be parallel or perpendicular to the floor system. Bridging, Strapping and Blocking Framing members that create a load sharing condition between adjacent floor joists. The introduction of such members can increase the span of a floor joist system. This effect will become apparent when we design floor systems. These framing members also provide stabilization – no twisting of floor joists. Can interfere running ductwork parallel inside joist space. I-Joists Typically referred to as pre-engineered floor joists. Manufactured products are made up of an assortment/combination of woods, wood products or metals, depending on the manufacturers. High strength/weight ratio. Dimensionally stable, stiff and strong. Large openings are possible. Hole charts are provided for solid webs (never cut a flange). Long spans available. Light Frame Wood Trusses Parallel chord truss. Prefabricated structural frames. Wide variety of shapes, designs and sizes are possible. Trusses consisting of individual members that are joined together to form an array of interconnected triangular forms. The triangle is a naturally rigid geometric shape that resists being distorted when loaded from any direction, a truss is more rigid than a beam with the same amount of material. Composite Trusses Larger spans. Light. Accommodate mechanical systems. Notching and drilling floor joist Holes are typically drilled to install electrical services, drains and waste piping. Wood Frame Systems - Loads Two Types: 1. Loadbearing walls: Wall framing supports floor and/or roof loads. Interior or exterior walls. 2. Non-loadbearing walls: Room partitions, typically interior walls. Exterior non-load bearing walls are rare. Live Loads: Loads that do, or can, change over time, such as people walking around a building, or movable objects such as furniture, mobile fixtures, wind rain, snow or seismic. Dead Loads: Refer to loads that relatively don’t change over time, such as the weight of all permanent components of a building including walls, beams, columns, floor material as well as permanent equipment and fittings that are an integral part of the structure (plumbing, HVAC etc.) Wood Frame Systems - Loads Floor systems receive loads on the floor and distribute these loads to structural elements such as walls or beams. Joists span: From wall to wall. From walls to beams. Or any combination. Subfloors 1. Floor sheathing 2. Provide a structural bearing surface. 3. Supports loads and transfers loads to the floor joists. 4. Typically, a tongue and groove panel product: Plywood, OSB, Waferboard or particle board. 5. Lumber may be used as well. OBC REFERENCES 9.23.4. Maximum Spans 9.23.5. Notching and Drilling 9.23.6. Anchorage 9.23.7. Sill Plates 9.23.9. Floor Joists 9.23.14. Subflooring Module 8 beams 1. Spans. 2. Beams: Steel Beams. Wood Beams. Beam Pockets. Bearing. Spans There are two types of spans: 1. Nominal Span: Early in the design process these “general or overall” dimensions give designers an idea of the depth of framing members likely to be required. Nominal spans typically indicate the overall width of a building or the dimension from the outside face of a building to the center of an interior support like a beam. 2. Actual Span: The actual span or “clear” span is the dimension from the face of one support to the face of the other. This exact dimension becomes clear as the design matures. This is the dimension that determines the minimum depth of the floor joists. The nominal span here is the width of the building which is usually known at the beginning of the design work. This case, the overall outside dimension of this building is 3600mm. Let’s determine the actual span of the floor joists, assuming the minimum OBC requirements. The actual or clear span is from the face of sill plate to face of sill plate. Designing Beams Beam size is determined by two factors: The floor load that it is carrying. The distance between the beam supports, or the beam span (Actual Span). * Within the constraints of Part 9 of the OBC, beam tables have been simplified to incorporate evenly distributed load conditions. OBC REFENCES 9.23.4. Maximum Spans 9.23.8. Beams to Support Floors 9.23.9. Floor Joist Module 9 - Stairs 1. Components and Terminology. 2. Understanding Stairs and the OBC. 3. Stair Construction. 4. Fire-rated Stairs. City of Ottawa Accessibility Design Standards Understanding Stairs and the OBC Ontario Building Code – Part 9, Section 9.8 Stairs, Ramps, Handrails and Guards. 1. Width. 2. Uniformity and Tolerances for Risers and Treads. 3. Stair Configurations: Rectangular Treads. Angled Treads. Winders. 4. Leading Edge. 5. Landings. 6. Handrails. 7. Guards.  8. Headroom. Guards Guards are a protective barrier, with or without openings through it, that are around openings in floors, or at the sides of stairs, landings, balconies, galleries, mezzanines, raised walkways or other locations to prevent accidental falls from one level to another OBC references 9.8. Stairs, Ramps Handrails and Guards Module 10 stairs continued 1. Module 9 - Stairs Review. 2. Calculating the rise and run. 3. Height over stairs. 4. Landings. 5. In-class Exercises 1-8. 6. AS1: Stair Assignment – Value 5%. Steps to Calculate the Rise and Run Calculate: 1. The total rise. 2. The number of risers. 3. The height of each riser. 4. The total run. The number of risers Calculate the number of risers using the maximum rise: 2752mm floor to floor height ÷ 200 max. rise = 13.76 risers. We cannot have 13.76 risers so we round it up to 14 risers In-class Exercise 2 Calculate the number of risers using the minimum rise: 2854mm floor to floor height ÷ 125 min. = 22.8 risers. We cannot have 22.8 risers so we round it down to 22 risers. Height over stairs The height over stairs shall be not less than 1950mm or 6’-5” in a house and induvial dwelling unit. The minimum stair width is 860mm or 34” O.B.C reference 9.8 stairs ramps handrails and guards.