Structure - Final Flashcards
7 functions of walls
- Transferring live and dead loads to the flooring or foundation system
- Resist racking
- Support interior and exterior finishes
- Hide electrical and mechanical systems
- Accommodate thermal insulation
- Provide sound insulation
- Provide privacy
5 Loads on walls
- Dead loads from structural members
- Snow loads
- Wind loads
- Earthquake loads
- Live loads from people, furnishings and contents of homes
6 materials for masonry walls
- Brick
- Stone
- Concrete Block
- Cinder Block
- Clay tile
- Glass Block
How are the two thickness (wythes) in masonry wall held together?
- Header bricks
- Metal ties
Masonry walls that extend above the top floor ceiling joists are prone to:
Leaning outwards
Masonry walls are strongest in which force?
Compression, Tension, Bending
Compression
10 masonry wall problems
- Cracks
- Leaning, bowing, or bulging
- Mortar deteriorating or missing
- Wavy brick walls
- Excess corbelling
- Bricks (cored) installed on their sides
- Prior repairs
- Deterioration of the masonry
- Efflorescence
- Too close to grade
General approach to cracks? 8 questions to ask
- What kind of wall is it?
- What has moved?
- Which way has it moved?
- How far?
- Is it still active?
- Why has it moved?
- What are implications?
- What should be done about it?
Step by step approach to crack analysis
- Number of cracks
- Continuity of cracks
- Type and orientation of cracks
- Amount and direction of movement
- Related problems
- Still active
- Cause
- Implications
- Recommended action
T or F
Crack analysis should be done only from the outside
False
T or F
Crack over openings do NOT always indicate severe problems
True
6 causes of leaning, bowing or bulging masonry walls.
- Inadequate lateral support
- Foundation movement
- Sagging or sloping floor systems
- Rafter spread
- Failure of ties
- Brick expansion
Cause of bulging masonry walls below windows?
Leaking water at the window has rusted metal ties
Which walls tend to expand over time, after original construction
concrete brick
clay brick
wood frame
concrete block
poured concrete
clay brick
7 causes of mortar deterioration
- Weathering
- Poor quality mortar
- Poor job of laying the mortar
- Weather was too hot
- Weather was too cold
- Mortar set too long before being used
- Additives to the mortar weakened it
What causes wavy brick wall?
The walls may have been laid up too quickly or the mason may have skimped on the amount of mortar on the back part of the bricks.
Staggering bricks so that higher bricks project out beyond bricks below, is a called:
Corbelling
Maximum limit for corbelling is?
1/3 of wall thickness (Canada)
1/2 of wall thickness (US)
T or F
Hollow concrete blocks are weaker if laid on their sides
True
T or F
Patched cracks on brick are a sure sign of serious structural movement
False
In _________ framing, the wall studs extend through the subflooring
Balloon
All of these words mean the same thing except –
a) sill plate
b) top plate
c) base plate
d) bottom plate
e) sole plate
b) top plate
T or F
Bearing walls and partition walls are built in substantially the same way.
True
T or F
Walls see vertical loads only.
False
T or F
Openings in partition walls need headers.
False
Jack studs carry __________ loads.
Header
Horizontal wood braces installed between studs to prevent buckling. They are typically installed near the mid-point of the wall.
This is a description of _________
Girts
3 functions of wall sheathing
- Support the siding.
- Stiffen the walls
- Keep wind and water out of the building
4 ways to prevent racking of exterior wood frame walls.
- Interior finishes such as drywall, plaster or plywood
- Exterior sheathings
- Panel-type sidings
- Diagonal bracing
T or F
No sheathing is needed if the building is otherwise protected from racking and weather, and the siding needs no support.
True
What is the difference between waferboard and OSB?
In waferboard, the pieces are randomly oriented. In oriented strandboard (OSB), the wafers are aligned, at least on the faces of the panel.
T or F
Adjacent pieces of plywood sheathing should be butted tightly to enhance weather-tightness.
False
T or F
Sheathing paper (building paper) should act as a vapor retarder.
False
Loadbearing wall studs should have holes no larger than:
a) 1⁄4 to 1⁄8 of width, depending on authority
b) 1⁄4 to 50% of width, depending on authority
c) 1⁄3 to 40% of width, depending on authority
d) 1⁄3 to 60% of width, depending on authority
e) 1⁄2 to 60% of width, depending on authority
C