A ADVANCED CONSTRUCTION McGill University School of Architecture Fall 2008 SAMPLE QUESTIONS FROM REQUIRED READINGS

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1 SAMPLE QUESTIONS FROM REQUIRED READINGS The following questions are intended to help you prepare for the quiz. If there is something in the readings you don t understand, please bring it up in class. Working in study groups is encouraged. Linda Brock, Designing the Exterior Wall: An Architectural Guide to the Vertical Envelope (John Wiley & Sons, 2005) Chapter 1 Decisions that affect the exterior wall The author divides modern buildings into 4 parts. Which part is the architect typically responsible for and why? How is durability defined and what are the three elements that need to be addressed? What is the purpose of the book? How can municipal regulations (like calculating floor space ratio) affect the envelope design and durability? What decisions affect the exterior wall design at the pre-design phase? Design phase? Construction phase? Occupancy phase? What is the difference between prescriptive, proscriptive, and performance specifications? If you had an architectural practice and fees were tight on a project, what would be your general approach to the envelope design and why? What question would you ask your client to verify whether the construction budget is appropriate? List some strategies to improve building durability? How can poor envelope design affect the health of building occupants? Within the prevailing global economy, why is it critical to understand regional differences? Give some examples. What quality control mechanisms does the architect use during the construction phase? What kinds of forces will weather and deteriorate a façade? Study how do the first 4 points impact point 5? Study the list on 1.5 Why is it unrealistic to try to seal a wall so that no water enters? What is the number one problem affecting envelope durability and what is the specific weak point? Study the recommendations for wall design in section 1.6 what are the particular considerations at ground level? What aspects of the modernist aesthetic influence durability? Define: value engineering, contingency, shop drawings, record drawings, maintenance manual, and differential movement.

2 Chapter 2 Water barriers and flashings Describe some destructive forces created by the presence of moisture and give some examples of the potential damage? For water to penetrate the building envelope requires 3 things: a source of water, a force to move it, and an opening. What are the sources of moisture in buildings? Why is the minimum recommended dimension of a drainage cavity not less than 10mm? Why does this increase to 50mm for a masonry veneer? List and understand the difference between the various water management systems. What is the purpose of pressure-equalization and how is it achieved? How does the author define rain screen? What is the problem with a face-seal approach? and where is it appropriate? Study Table 2.2 the forces that move water through the wall. List the 5 forces and give an example of how to stop the force. Why should we treat a window sill as a roof? Understand the different types of water barriers. Why are peel-and-stick membranes (generally a vapour barrier) potentially problematic as a water barrier? (Think of the different functions and placements of air barrier, water barrier, vapour barrier, and insulation.) What is the main weakness in a panelized water barrier? What is the danger inherent in applying a water barrier on the outer surface of an exterior wall? Explain. What is flashing? Where is it required? List five major flashing problems? Why does the author present the expansion coefficient for each of the flashing materials listed in table 2.3? Why should sheet water barriers be lapped with each other and with the flashing? Define: efflorescence. drip edge, oil canning, compatibility (of materials), cleat fastener. Chapter 3 Air barrier systems, vapour retarders and insulation How can protecting the components of an exterior wall from direct sunlight improve durability? What is the difference between an air barrier and an air barrier system? Why is the air barrier system so important? What is its role in preventing moisture from getting into the exterior wall? How does it affect thermal performance? What is the difference between an air barrier and a vapour barrier? Why is an opening in an air barrier more serious than in a vapour barrier? Why does the type of water barrier influence the choice of air barrier?

3 Why is a polyethylene vapour barrier not typically a good choice for an air barrier? Review the different types of air barrier systems. What are some of the advantages and disadvantages of each type? What are the most vulnerable components of an air barrier system over time? How can air tightness be tested and air leaks identified? Water vapour in the air seeks equilibrium with surrounding air and materials this is the cause of vapour diffusion or drive. What is the typical direction of vapour drive? List some interior sources of water vapour and how it is evacuated from buildings. Why does the placement of a vapour barrier differ depending on climate and when is it not recommended? Review the list of common vapour retarders. Which are not appropriate for a heating climate and why? In a cooling climate, how might vinyl wallpaper be problematic? What should be the primary focus of an architect regarding vapour management? Why should there only be one vapour barrier in a wall assembly? What are the 3 forms of heat transfer and for each give a building example of how it can be contained or resisted. What are the qualities of insulation that contribute to its effectiveness? What other qualities might affect the choice of product? Review the different types of insulation. What are some of the advantages and disadvantages of each type? Thermal resistance should be measured for the whole wall, not just through the section with insulation why? What is the best placement of insulation to avoid problems of differential thermal movement, thermal bridging, and thermal stress of wall elements? In medieval times, tapestries were hung on stone walls to improve comfort. Winter cabins often use foil backed insulation explain how these materials can improve thermal comfort even though they have minimal insulation value. What glazing technologies have improved the thermal performance of glass? Why are heating elements usually located under windows? Define: stack effect, dew point, thermal bridge, thermal break, infrared thermography Chapter 4 sealant joints What kinds of movement are buildings and materials subject to? Consider how this may affect the exterior wall. Where are the joints to allow for this movement? How much can steel expand when it rusts? How might this affect a masonry or pre-cast concrete wall?

4 What is the difference between an expansion joint and a control joint? What is the purpose of a joint sealant? What are the characteristics of a good sealant joint (see figure 4.7)? What is the minimum typical sealant joint size? How can a joint be sealed using rain screen principles? What is the minimum size of this type of joint? What are construction tolerances? How might this affect the size of cladding joints? What are the properties of sealants that will influence the selection of a product? Why does the author consider it foolish not to use the highest-grade sealant for a given application? Why is the ambient temperature critical when applying a liquid sealant? Review the types of joint sealant. What is the role of a backer rod? bond breaker tape? Define: backup wall, story drift, creep, shelf angle Chapter 5 curtain walls What technological advances have permitted the fully glazed curtain wall buildings that are so common today? What other materials are common in curtain wall systems? What is the difference between curtain wall and window wall? What is the difference between a stick system and a unitized system? Describe two structural glazing systems. Review the different types and characteristics of glass? What is the set of seemingly contradictory qualities that architect s so often desire of glazing? What is the purpose of injecting an inert gas like argon into a sealed glazed unit? List some of the metal cladding panels used in curtain wall construction and advantages of each type. What techniques are used to reduce the weight of stone cladding? How thin are thin stone panels? List some of the common stone types, their properties and criteria for selecting stone. Who provides input on the design of curtain walls? Examine the fixing in figure 5.9. Why is adjustment in all three directions necessary? How can joint size affect life-safety in a curtain wall assembly? How can air and water leakage be minimized in the design of an aluminum glass curtain wall? What maintenance cost should be considered when proposing a double glazed façade or any other complex curtain wall forms?

5 Why must architects pay special attention to curtain detailing at points of transition like at the base of wall, roof and adjoining claddings? List the main causes of water leakage problems in curtain walls? Define: float glass, safety glass (annealed, heat strengthened, tempered), laminated glass, insulated unit, warm edge spacers, tinted glass, coatings (solar reflective, low-emissivity), spandrel glass, ceramic frit, aluminum panels (honeycomb backed and aluminum composite material), galvanic action