Structure Flashcards
What are the three ways a structure may give in to gravity?
- if it is sitting on something that is not strong enough, the ground below will fail.
- if the skeleton of the structure is weak, it will not support itself,the weight of the structure itself is the ‘dead load’
- if the live load on the structure is greater than expected, it will collapse.
What causes structures to move?
Gravity
The two basic forces that individual structural components are subjected To are?
Compression-pushed from both ends
Tension-pulled upon
What conditions may result in inadequate lateral support?
The walls will deflect inward
Foundations should extend at least how far above grade ?
4 to 6 inches
What are two common footing problems with piers?
Inadequate footing and pier base not below the frost line
What limits the inspection of crawl spaces ?
- entry size
- lack of lighting
- cramped work space
What is the function of beams ?
To carry floor and wall loads horizontally to the foundations , walls or posts
Where are joist hangers required ?
Where joist can not rest on a support
What two functions do bridging and bracing perform?
Restrain the joists from twisting and to transmit loads from one joist to the Next
What materials were/are commonly used in sub flooring?
- one inch wood boards
- plywood
- oriented stand board (OSB)
What is the difference between balloon framing and platform construction?
- in balloon framing,the wall systems are erected before the floor systems
- in platform framing the floor system is erected before the wall system
- in balloon framing the wall framing extends from the foundation to the roof
- in platform framing the wall framing is built on floor at a time
What purpose do weep holes serve?
- To allow the rain water to drain out of the 1” air space
- balance the pressure on both sides of the brick
What is the difference between post- and-beam construction and conventional wood-frame construction.
Post and beam construction uses a few loathe members for support where conventional construction uses many smaller members.
What function do lintels perform?
To transfer The load above an opening In a masonry structure
Steel lintels on masonry walls should be at least how many inches wider than the opening on either side
6 inches
Where should collar ties be attached to the rafters:
Near the middle
What function do knee walls perform ?
Support the roof rafters and prevent sagging.
What concern, other than structural,arises with a misaligned-aligned chimney ?
- Heat gets near combustible materials
- Smoke and CO can re-enter the house
- Creosote can collect in the attic
What can one do to minimize the risk if termite infestation?
Breaking earth to wood contact
What causes wood rot?
- Improper ventilation
- Too much moisture
A 2”x6”@16” on center can safely span ?
Depends on species of wood
What is the best way for steel girders (I-beams) in basement concrete wall pockets to be installed?
1/2” gap on 3 sides
How are hurricane ties attached at the roof structure ?
Inside edge at top plate to rafter
CDX is what type material?
Exterior grade plywood
Step cracks in masonry wall at top corner of a window angled up and away are caused by
Rusted lintel
