Glencoe: 17 Flashcards
How do you check Land Elevations:
Set up level or transit.
Make sure all leveling rod locations can be seen through telescope.
Read where horizontal crosshair in telescope croses the rods.
How do you measure the difference of elevation between two locations.
Place transit or level between two rods. Check the levels of both rods and subtract to figure out the difference.
How do you measure the elevation different in two remote locations with a mound or obstruction in the way:
Set up intermediary rod readings and place the transit or level in between them.
Differential leveling:
The process of determining the differences in elevation between points that are remote from each other.
Foundation wall footings must:
rest on firm soil below the front line.
Footings:
continuous concrete pads that support the foundation wall.
Depth of frost line varies according:
to local climate and is given in local buildings codes
What determines how deep an excavation must be
the frost line
After knowing the frost line, how do you determine where to start the depth of the excavation:
The highest point on the perimeter of the excavation as the reference point.
Both graded and ungraded sites use what to determine excavation depth?
the highest point on perimeter of excavation
Good drainage is ensured if
sufficient foundation height is allowed for the sloping of the finish grade
Finish grade is the
level of the ground when grading is completed.
Foundation walls of X high are necessary for full basements and Y is common
7’-4”
8’
The top of foundation wall must be at or above
a minimum set by code
The minimum the top of a foundation wall must be above is usually
8” above finished grade
Why must foundation wall be a certain height above finished grade?
it allows siding and framing members to be protected from soil moisture. And it makes termite activity visible.
Crawl spaces should have enough height to
allow for inspection of termite damage and allow plastic soil covers to be installed
What do soil covers do?
reduce the effect of ground moisture on framing members.
How many inches should be between undersides of the joists and the highest point of ground?
usually 18”
If the ground beneath the structure is excavated or is otherwise lower than the outside finished grade:
measures should be taken to ensure good drainage
Any variation from the standard construction practices
increases the cost of the foundation and footings.
Before excavating for a new home, subsoil conditions should be determined by
test borings or by obtaining soil samples in some other way.
Why should sub soil conditions be determined?
Helps the excavators to determine whether any special precautions will be necessary. Unusually soft or hard soil conditions may call for special excavation techniques or equipment.
Helps determine bearing capacity and porosity.
Bearing capacity is
a measure of how well the soil can support weight of house.
positive drainage for the X
Y inches of fall min
first 10 feet
6 inches of fall min
Added fill brings
the finished grade above the original grade and ensures drainage way from the house.
