Building, Structural & Snow Load Design

This section provides specific structural standards that are required for UBC projects and facilities. These requirements are intended to satisfy UBC's principles and goals to ensure that consistent structural standards and design criteria are applied to UBC projects.

• 2.2.1 Reference Design Code
• 2.2.2 Climatic Data
• 2.2.3 Supplemental Structural Drawing Information
• 2.2.4 Design Live Loads
• 2.2.5 Geotechnical Investigation
• 2.2.6 Materials
• 2.2.7 Structural Design of Non-Structural Components

2.2.1 Reference Design Code

The structural design and construction of buildings, facilities, and structural members shall be in conformance with the current addition of the British Columbia Building Code.

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2.2.2 Climatic Data

.1 The climatic values to be used for the design of buildings and facilities at UBC shall be in conformance to Table 2.2.2.

.2 Depth of frost protection shall be not less than 450 mm.

Table 2.2.2 Climactic Data for UBC Forming part of Sentence 2.2.2.1
1.	January 2.5% Design Temperature	-6ºC
2.	January 1% Design Temperature	-8ºC
3.	July 2.5% Design Dry-bulb Temperature	28ºC
4.	July 2.5% Design Wet-bulb Temperature	20ºC
5.	Degree-days below 18ºC	2950
6.	Ground Snow Load:
	Ground Snow Load (Ss)	1.9 kPa
	Associated Rain Load (Sr)	0.3 kPa
7.	Hourly Wind Pressures:
	Probability 1/10	0.36 kPa
	Probability 1/50	0.48 kPa
8.	Seismic Data:
	5% Damped Spectral Response Acceleration Sa(T)
	Sa(0.2)	0.95
	Sa(0.5)	0.65
	Sa(1.0)	0.34
	Sa(2.0)	0.17
	Peak Ground Acceleration (PGA)	0.47
9.	15 minute rainfall	10 mm
10.	One day rainfall 1/50	107 mm
11.	Annual Total Precipitation	1400 mm
12.	Driving Rain Wind Pressure 1/5	160 Pa

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2.2.3 Supplemental Structural Drawing Information

.1 In addition to the information specified in the BC Building Code, structural drawings and related documents shall include the following additional supplementary information:

• Identification of the loads and locations of any special loadings such as fire truck
  loading, storage areas, landscaped areas, areas with heavy equipment, or other
  unusual load conditions.
• Identification of areas of future additions indicating loads and assumptions.
• A key plan indicating design loads for floors with varying live loads.
• A complete detailed description of the lateral load-resisting system

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2.2.4 Design Live Loads

.1 Except as provided for in this clause, the minimum specified uniform live loads shall not be less than the values listed in Table 4.1.5.3 of the BC Building Code.

.2 The following minimum uniform live loads shall be used for the occupancies indicated. These increased values replace those indicated in Table 4.1.5.3.

Use of Area of Floor or Roof	Minimum Specified Load kPa
Equipment areas and service rooms	4.8
Libraries - Reading and study rooms	7.2
Office areas - floors above first storey	3.1
Recreation areas	4.8
Classrooms & lab floors (minimum)	3.6

.3 All roofs, are to be designed for a minimum net factored uplift suction of 1.0 kPa.

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2.2.5 Geotechnical Investigation

2.2.5.1 Site Classification Factor

1. The site classification factor for the soils shall be determined by a qualified Geotechnical Engineer.

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2.2.6 Materials

2.2.6.1 Concrete

1. Unless pre-approved by UBC, exposed concrete elements are to be treated as follows:

• Bottom edges of exposed slabs and beams, and exposed column and wall edges are to be beveled 20mm x 20mm.
• All top edges of exposed slabs, upstands, stairs, and other concrete

2. Slabs-on-grade are to be 150 mm minimum thickness, reinforced and provided with control joints. Reinforcing shall meet or exceed Code temperature requirements. Control joints shall be provided in each direction in an approximately square pattern, joint spacing not to exceed 4000 mm oc. Poly sheet to be placed below all interior slabs-on-grade.

3. Reinforcing steel that is part of the seismic load-resisting system shall conform to CAN/CSA G30.18W.

4. No calcium chloride, in any form, is permitted in any concrete mix.

5. Post tensioned floor systems are not preferred by UBC and require pre-approval and acceptance before being used for projects.

6. All exterior concrete to be air-entrained in accordance with CSA/CAN - A23.1/2

2.2.6.2 Structural Steel

.1 All structural steel shall be shop primed except for steel to be encased in concrete, steel to be fireproofed, steel to receive shear studs, faying surfaces of slip resistant connections, and the underside of base plates and bearing plates. Touch up any damaged areas using the same primer.

.2 All exterior ledger angles and related components (connections, bolts, etc.) not accessible after installation shall be galvanized for corrosion protection.

2.2.6.3 Steel Decking

.1 Steel decking shall be galvanized. Exterior exposures shall meet the Z275 requirements; Interior exposures may be wipe coated.

2.2.6.4 Wood Construction

.1 Woodframe structures are to be designed to Part 4 of the BC Building Code. The use of Part 9 for structural design is not acceptable.

.2 Sill plates are to be preservative treated and installed over foam sill gaskets.

.3 Wood members in contact with concrete or masonry are to be preservative treated and installed with a moisture barrier between the wood and concrete surface.

.4 Finger-jointed studs are not acceptable.

.5 Shrinkage must be considered and allowed for in all design and detailing.

.6 The maximum permitted moisture content of wood members is not to exceed the limits as specified in the Building Envelope section of these guidelines. In the absence of specific limits in the Building Envelope section, in no case shall wood members in a dry service condition have a moisture content exceeding the code limit of 19%.

.7 Wood products susceptible to moisture penetration or damage must be protected from moisture until completely installed and weather protected.

.8 Subfloors shall be constructed with exterior grade tongue and groove plywood, glued and screwed in place.

.9 Lateral Load-Resisting Systems

• The lateral load resistance of woodframe structures is to be provided by plywood
  shearwalls or other acceptable engineered systems complying with Part 4 of the
  BC Building Code.
• The use of gypsum wallboard in contributing to the lateral load resistance of
  woodframe structures is not permitted.
• Oriented strand board is not acceptable as sheathing for woodframe shearwalls.
• The load path of the lateral load resisting system must be clearly defined from the
  lowest level to the underside of the roof deck.
• Continuity of the plywood floor diaphragm must be maintained on all floors. Do not
  cut or stop the plywood at party-wall locations.

2.2.6.5 Masonry Construction

1. Load bearing masonry to be minimum H/15/A/H with Type 'S' mortar.

2. Minimum reinforcement to include 15m @ 1200 o/c vertically and #9 GA galvanised ladder-reinforcement every second course. Grout solid all reinforced cores.

3. Provide reinforced bond-beams at all floor levels and maximum 2400 o/c.

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2.2.7 Structural Design of Non-Structural Components

1. The structural design and field review of non-structural elements, restraints, and anchorages shall be provided by a professional engineer registered in B.C. Design shall accommodate all applicable load conditions (dead loads, live loads, wind loads, and seismic loads) and must conform to the current addition of the BC Building Code.

2. Letters of assurance for design and field review shall be provided by the engineer(s) responsible for the design of non-structural elements, and shall be submitted to the Structural Engineer of Record.

3. Non-structural elements include (but are not limited to) the following:

• Cladding, glazing, window mullions, and exterior wall assemblies.
• Architectural precast or other precast concrete.
• Architectural components such as guardrails, handrails, flag posts, canopies,
  ceilings, skylights, interior partitions, millwork, etc.
• Mechanical and electrical equipment, components and their attachment.
• Window washing equipment and their attachment.
• Escalators, elevators, and conveying systems.
• Brick, block, or masonry veneers and their attachment.
• Non-load bearing masonry.
• Glass block and its attachments.
• Non-structural concrete toppings.
• Landscape elements such as benches, light posts, planters, walls, etc.

4. Partition walls are to be detailed to allow for deflection of the structural building system.

5. The maximum allowable deflections for glazing, studs, partitions, and cladding under the design wind loads shall meet the architectural specifications, the BC Building Code and the manufacturer's specifications. In no case shall the deflections exceed the following:

• Elements supporting brick L/720, (max. 25mm)
• Elements supporting precast or stucco L/360, (max. 25mm)
• Elements supporting wood or metal siding L/180, (max. 25mm)
• Elements supporting glazing L/180, (max. 25mm)

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UBC Building Operations
2329 West Mall
Vancouver, BC, Canada
V6T 1Z4
Tel: 604.822.2172
Fax: 604.822.0208
Email: michael.thayer@ubc.ca