10 Flashcards
What causes movement in building components?
- Thermal movement
- Moisture movement
- Elastic deformation and creep
- Construction tolerances and other considerations
Steel movement types in buildings
Thermal, elastic deformation.
Concrete movement types in buildings
Thermal, elastic deformation, creep, and reversible moisture.
Concrete masonry movement types in buildings
Thermal, elastic deformation, creep, and reversible moisture.
Brick masonry movement types in buildings
Thermal, elastic deformation, creep, and irreversible moisture.
Wood movement types in buildings
Thermal, elastic deformation, creep, and reversible moisture.
Annual temperature range that a component is subjected to
This is the difference between the maximum and minimum temperatures of the component.
Thermal Movement
Generally the most critical movement, because it occurs in all components, particularly those exposed to the exterior climate, such as exterior walls.
Moisture movement in steel, copper, and aluminum
Moisture movement in steel, copper, and aluminum
These materials are generally dimensionally stable with respect to moisture.
Moisture movement in portland cement
Materials with a portland cement base tend to shrink due to moisture loss.
Moisture movement in concrete and masonry
Clay masonry units expand on absorption of water or water vapor. This expansion is irreversible.
Moisture movement in wood
Wood shrinks and swells, depending on the ambient air’s humidity and temperature, changing in dimensions.
Material with the highest coefficient of thermal expansion
Plastics.
Creep Deflection
Time-dependent additional deflection of the beam is known as________.
Elastic Deformation
Building components are designed to remain elastic under loads. Also known as instantaneous deformation. These are routinely determined for all types of structures and are a part of the structural calculations.
Joint detailing of an expansion joint
The filler of the joint must be elastomeric to allow for unrestrained movement of the components.
Joint detailing of a control joint
This filler can be elastomeric or nonelastomeric. The detailing must allow for unrestrained shrinkage of the components.
Difference between expansion joint and control joint
Control joints occur in concrete masonry or masonry walls. Expansion joints are provided in almost all components because temperature-induced movement is universal.
Purpose of sealing a joint
Primary reason: to prevent water penetration. Control of air leakage, dust penetration, and noise transmission are additional benefits.
In addition to joint sealants, what other components are important to a sealed joint?
- Substrate
- Primer
- Sealant Backup
- Bond Breaker
What is important for sealed joints with regards to the substrate?
The chemical compatibility of the sealant with the substrate material is critical to the adhesion of the sealant.
Purpose of a primer in sealed joints
Improve adhesion of the sealant to substrate.
Backer rod functions
- Controls depth and shape of sealant
- Allows the tooling of the sealant, which gives adhesion between the sealant and substrate
- Acts as a temporary joint seal until the sealant is applied
Bond Breaker
This is required only if the third surface is hard and unyielding (e.g., concrete, metal, masonry).
Three categories of joint sealants
- Preformed Tapes
- Caulks
- Elastomeric Sealants
Types of elastomeric sealants
- Polyisobutylene
- Acrylics
- Polyurethane
- Polysulfide
- Silicone
What elastomeric sealants are best for minimal movement and are used as caulking materials?
Polyisobutylene and acrylic sealants.
What is the most important property of a sealant?
It is its ability to withstand cyclic joint movements. Sealants are classified into three categories:
- Low-range
- Medium-range
- High-range
Low-Range Sealants
Have limited movement ability to the order of 5% or less. Included in this category are
- Oil-based caulks
- Butyl or acrylic caulks
Medium-Range Sealants
Have movement range of up to 12.5%.
High-Range Sealants
Have movement range larger than 12.5%. Silicone is considered to be in this category and has a movement range of more than 50%.
Lapped Joints
Joints that do not need to be sealed because building components overlap. Examples of these joints are:
- Joints between exterior wall siding
- Joints between roof shingles or tiles
- Joints between underlayment felts below shingles
Life expectancy in sealants
This refers to the time after which the sealant is first installed that it would need to be reapplied. High-grade sealants have a life expectancy of more than 20 years.
Energy Star Labels
Introduced by the EPA to recognize energy-efficient computers, this is an international energy-labeling system that labels home and office appliances, light sources, windows, etc.
Certified Wood Label
Carried by wood products that have been produced by manufacturers according to guidelines promulgated by the Forest Stewardship Council.
Green Label and Green Label Plus
Mark assigned to the carpet, rug, and cushion materials that have low VOC emissions. Green Label Plus is more stringent.
Green Seal Label
A comprehensive, life-cycle environmental evaluation of a product based on EPA and International Standards Organizations standards.
Casement Window
This window type may consist of one operable sash. The sash closes on the frame with pressure providing a compression seal. This window is generally less prone to air leakage and can be more energy efficient than single, double, or sliding windows. It can provide 100% ventilation.
Sliding Window
This window type consists of one sash that slides horizontally over a fixed sash. It can provide up to 50% ventilation.
Awning Window
This window type is similar to a casement window but provides rain protection when partially open. It opens from the bottom and hinges at the top. It can provide 100% ventilation.
Hopper Window
This window type is similar to an awning window but opens inward at the top. It can provide 100% ventilation.
Pivoting Window
This window type may be pivoted at the center or off-center. It allows for up to 100% ventilation.
Double-Hung Window
This window type consists of two sashes, both of which can slide up and down. The maximum ventilation provided is 50%.
Single-Hung Window
This window type consists of one sash that can slide vertically over a fixed lite. It can provide up to 50% ventilation.
Fixed Window
Generally does not have a sash because the glass is held directly by the window frame. There is 0% ventilation.
Triple Hung Window
This window type consists of three sashes, all of which can slide up and down. It provides ventilation both from the top and bottom.
Picture Window
This is a fixed window that has a width larger than height to provide a panoramic view.
Five materials used in contemporary windows
- Wood
- Aluminum
- Steel
- Vinyl
- Fiberglass
Advantages of wood windows
This is one of the oldest window materials. It has a high R-value and its warmth and beauty make it desirable. They are generally used in high-end homes and offices.
Advantages of aluminum windows
This is the most common window material. It is not subject to moisture shrinkage and swelling. They require very little maintenance. They have a lot of flexibility and malleability and can be extruded into complex cross sections.
Advantages of vinyl and fiberglass windows
These windows require no painting and are available in a variety of non-fading colors. They are maintenance-free because the material doesn’t corrode or degrade.
Advantages of steel windows
These windows are strong and frame members can be narrower than those of other materials, giving a sleeker appearance.
Windows must be tested for:
- Resistance to wind loads
- Resistance to water leakage
- Resistance to air leakage
- Resistance to forced entry
Subsill
This is a part of a window that catches incidental water that might leak into the window. It has end dams to prevent its runoff from the ends and also weep holes to let the water drain out.
Name the ratings that fire doors come in.
3-hour-, 90-minute-, 60-minute-, 45-minute-, and 20-minute-rated door.
What is the purpose of a 20-minute fire-rated door?
This door’s purpose is to minimize the transmission of smoke from one side of the door to the other. It is usually required in a 1-hour-rated corridor wall.
What are hollow metal doorframes made from?
Sheet steel that is pressed into shape.
What are two ways hollow metal doorframes can be installed?
1) Buts against the jambs of a CMU wall
2) Wraps around the jambs of a CMU wall
Stile
A vertical sash member.
Rail
A horizontal sash member.
Muntins
Thin horizontal and vertical dividers, commonly used in early windows when large sheets of glass were not available.
Weather Stripping
A strip of resilient material that provides a seal between the sash and the frame to reduce air and water leakage.
Glazing Stop
A feature that holds the glass against the rabbet in the sash or frame.
Rabbet
A step in a sash or frame cross section against which the glass is held.
Gasket
A strip of resilient material between the glass and the glazing pocket.
Daylight Opening
Visible glass area in a window.
Window Hardware
Hinges, latches, locks, levers, and so on.
Stool
A horizontal trim member that abuts against the windowsill and covers the rough sill.
Jamb Extension
A horizontal or vertical trim that covers the rough head and jamb and extends the depth of window frame.
Apron
The trim installed on the wall under the stool.
Casing
Decorative members that cover the joints between adjacent materials.
Rough Opening
The opening within which the window is placed.
Punched Window
Strip Windows and Glazing
Window Wall and Glass Curtain Wall
A window with an opaque wall around it.
An array of windows placed side by side to form a horizontal strip window system.
A wall in which the windows extend from floor to roof or from floor to floor, called a window wall.
Projected Window
Includes windows whose sashes project out of the window plane when open, such as casement, awning, hopper, and pivoted windows.
Nailing Flange
Some manufacturers provide windows with this. It runs continuously over the outside of a window frame and functions as a flashing. It provides a means of anchoring the window-to-wall opening.
What are the two most important components of a window?
1) Window frame
2) Window sash
Alclad
This material contains an aluminum alloy core that is metallurgically bonded to pure aluminum on the surface. It is a more expensive process than anodizing and is commonly used in aircrafts.
What are two types of paint finishes for aluminum?
1) Baked-enamel coating
2) Fluoropolymer coating
PVDF Finish
Polyvinylidene fluoride (PVDF) resin; strong and durable and is primarily suited for exterior applications. A wide range of colors, including exotic colors are available. It comes with two types of durability ratings: 5 year and 10 year.
What are three commonly used glass-aluminum wall systems?
1) Glass-aluminum curtain walls
2) Punched and strip glazing systems
3) Storefront systems
What are the five categories glass curtain wall systems are divided into?
1) Stick-built systems
2) Unitized systems
3) Unit and mullion systems
4) Panel systems
5) Column cover and spandrel systems
What are two types of mullion spans generally used in stick-built glass curtain walls?
1) Single-span mullion systems: each mullion extends only over one floor.
2) Twin-span mullion systems: the mullions extend over two floors.
A stick-built glass curtain wall is anchored to the structure through ________.
Mullions.
Purpose of exterior and interior gaskets on a curtain wall
This prevents water from leaking through the wall. Curtain walls have accommodations for the drainage of water if it penetrates beyond gaskets.
Most important requirement for a curtain wall
The most important requirement is its ability to resist lateral loads, specifically wind loads, including missile-impact resistance in hurricane-prone areas.
Important design criteria for a curtain wall
- Air-infiltration control
- Rainwater- and meltwater-penetration control
- U-value
- Solar heat gain
- Condensation resistance
- Vapor diffusion
- Acoustical transmission
- Hurricane resistance
- Seismic resistance
- Thermal and structural movement
- Glass-cleaning equipment load
Minimum requirements for treads and risers
Minimum tread width: 11”
Riser height: 4–7”
Most commonly used stair shape
U-shape stair. Two flights of stairs between floors with a mid-floor landing.
Circular Stair
This stairwell may consist of all winders and can take many shapes. A spiral stair is a special type within this category, where the treads twist around a column and are cantilevered from it. The building code has severe restrictions on the use of spiral stairs.
Head Room
Minimum clearance between a tread and a projection above. Building codes generally require the head room to be a minimum of 80” at any point on the stair.
Guard Unit
This protects the edge of a stair, which is exposed. It is required by code and has a minimum height of 42”. The clear distance between openings is 4” diameter.
Nosing projections
Less than 1 1/4”.
Handgrip requirements for handrail
Circular cross section between 1 1/4” and 2 5/8”; noncircular profiles must provide equivalent graspability.
Stair width design criteria
This is a function of occupant load but not less than 48” for enclosed stairs, 44” for open exit stairs, or 36” for a stair serving an occupant load of less than 50 or a residential stair.
Equation for determining riser and tread dimensions in a stair
2R + T = 24” to 25”.
The rise of one flight of stairs is usually limited to ____.
12’ per code.
Most important part of a wood stair
Carriages: structural elements of a stair that are specially cut to support the treads.
Landing Frame
Landing of a steel stair framed with structural steel members as a unit. The frame is supported by suspending it from the upper-level floor beams with hanger bars.
Helical Stair
Self-supporting, circular steel stairs can be constructed with or without landings. These are fairly common in steel, concrete, and wood. There is no central column support.
Two types of subfloors
1) Concrete subfloor: elevated concrete floors and concrete slabs-on-grade
2) Wood subfloors: wood panels supported by wood light frame or light-gauge steel frame members
Slip Resistance
Floor coverings should be resistant to people slipping and falling.
Types, amount, and frequency of traffic
Floor coverings should be suitable for the abrasive impact that pedestrian foot traffic will have on it. Foot traffic impact can be measured by the number of crossings per day.
Durability and longevity of floor coverings
Should be durable enough to endure any expected use and provide an adequate service life; should be selected to resist staining from liquids, chemicals, and reagents.
Flammability of floor coverings
Building codes require resistance to fire propagation for some applications.
Sound absorption of floor coverings
Floor coverings that absorb sound can lower the airborne noise level within rooms.
Sound isolation of floor coverings
Floor coverings can improve the impact insulation class when building codes mandate minimum sound isolation requirements for floors.
