Footings Flashcards
(17 cards)
According to the national building code what is the minimum thickness for column footing?
100 mm
List two types of footings used for interior support?
Continuous and column or pad
What material are footings usually made of?
Concrete
What is the elevation of an interior footing in relation to an exterior footing?
The same elevation
Why does the interior continuous footing have a raised centre?
To prevent moisture problems.
If a column footing has a 200 mm projection what is the minimum footing thickness?
200 mm
What is the minimum pad footing area for columns that are spaced 3.5 m apart and support the load of two floors? What is the minimum dimension of these footings?
Minimum footing area:
0.75m2 x 3.5/3=0.875m2
NOTE: footing area adjusted for increased spacing of columns
/.875m2=0.935m
Footing dimensions: 935mm x 935m
If I footing is 200 mm thick ,what is the maximum projection allowable?
200 mm
According to the national building code, what is the minimum footing thickness allowable?
100 mm
What is used to prevent lateral movement of the foundation on the footing?
Keyway
What is the maximum height of arise on a step footing?
600 mm or 2 feet
List two methods used to counteract The effects of high water table.
A.raising the footings
B.double footing width
What type of footing is used if the elevation around the building varies significantly?
Stepper footings
When calculating the depth of the foundation, from where is the depth measured?
Underside of footings.
What percentage of roof load is taken by a typical exterior wall footing?
50%
What is the main function of a footing?
It serves to increase the area of a structure, that is in contact with stable soil, supporting foundation walls and the rest of the building structure
What percentage of floor load is taken by typical interior pad footing
50%
