Section 2 Flashcards
What is a firestop?
A firestop is a system consisting of a material, component and means of support used to fill gaps between fire separations or between fire separations and other assemblies, or used around items that wholly or partially penetrate a fire separation.
What is a fire block?
A fire block is a material, component or system that restricts the spread of fire within a concealed space or from a concealed space to an adjacent space
Name 3 factors that affect the severity of vertical flame extent in a wall cavity.
The vertical flame spread in the wall cavity is highly dependent on:
- The type of framing members (wood or steel)
- The width of the air gap
- The degree of cavity venting.
Name the main performance requirements of the window as a system.
To Control:
- heat flow
- air leakage
- water vapor flow
- condensation
- rain penetration
- sound transmission
- strength & durability
- entry of insects
- ease of operation
If the glass itself in a window system has negligible resistance to heat flow, how is thermal resistance provided in a glazing system?
The thermal resistance of the glazing comes from the airspace between the panes of glass and from the thin films of air at the inside and outside surfaces of the assembly that slow down the heat transfer.
Coatings of low emissivity applied on glass or plastic to reduce the flow of heat radiating from objects and people inside, and gases other than air to fill the cavity of sealed glazing units are the most recent available developments for increasing the RSI value of glazing.
In certain cases (i.e. heritage buildings) where windows are retrofitted instead of replaced, how is thermal performance improved in this instance?
Adhesive films may be applied on the existing glass to control solar heat gains and reduce internal heat losses.
Where are windows most susceptible to air leakage and how is this mitigated?
Windows must resist air leakage, which affects energy control, comfort and condensation potential. Since the materials themselves have rather low permeability to air, the junctions between materials are the main areas requiring attention. Sealants and gaskets are used for the fixed parts of the window, while weather strippings are used for the operable parts of the window.
Name the 6 strategies applied to reduce sound transmission in gypsum wall board assemblies.
- Use double studs, staggered studs (with or without resilient channels), non-load-bearing steel studs, wood studs with resilient channels or load-bearing steel studs with resilient channels;
- Increase mass by increasing the number of layers of gypsum board on each side from one to two;
- Increase the depth of the cavity;
- Fill the cavity with insulation;
- Space studs at 600 mm; and
- Space resilient channels at 600 mm.
What is the primary purpose of thermal insulation?
The primary purpose of thermal insulation is to control the flow or transfer of heat through the exterior assemblies of a building
In a roof assembly, where are the three locations that thermal insulation can be installed?
- Below the structural roof deck
- Between the roof deck & roofing membrane
- Above the roof membrane
What is the purpose of an air barrier?
An air barrier contains the primary joint seals, controls the flow of air and noise through the wall, and is airtight and rigid enough to withstand wind pressures. The air barrier itself may be a continuous membrane placed on either side of the insulation or on either side of the interior wall layer.
What does a rainscreen wall consist of?
- An outer layer of cladding (the rainscreen)
- An air cavity
- A drainage plane on a rigid, water-resistant, and airtight support wall
What are pressure-equalized rainscreen (PER) walls?
PER walls utilize vented cladding and an air cavity, often divided into drainable compartments, to facilitate pressure equalization with the outside atmosphere and limit water penetration through joints in the cladding assembly
List 5 factors that affect heat loss or gain in a construction assembly:
- Surface color & reflectivity of materials used
- Mass of the assembly, which affects the time lag or delay before any absorbed and stored heat is released
- Orientation of the exterior surface of the building
- Latent heat sources and heat gain from the occupants, lighting, and equipment within a building
- Proper installation of thermal insulation & vapor barriers.
What is an expansion joint?
Expansion joints are continuous, unobstructed slots constructed between two parts of a building or structure permitting thermal or moisture expansion to occur without damage to either part. Can also serve as control and isolation jionts.
