Glencoe: 16

Question 1

Two basic types of surveying instruments commonly used in residential construction are:

Answer 1

Levels and transits. Both sit atop a tripod

Question 2

Levels:

Answer 2

The telescope of a level is fixed in a horizontal plane. It can be used only for measuring horizontal angles because it cannot be tilted up or down.

Question 3

Builders level:

Answer 3

Sometimes called a dumpy level. It is the least expensive surveying instrument. Must be set up carefully to ensure accurate results. A good quality model is usually accurate within +- 1/4” at a distance of 75’

Question 4

Automatic level:

Answer 4

automatically adjusts for variations in setup. It takes less time and effort to set up than a builders level. It is also more accurate, usually to +- 1/4’ at 100’. Some are accurate to +- 1/16 at 200’

Question 5

Laser Level:

Answer 5

Does not have a telescope but is set up on a tripod like other levels. Projects laser horizontally.

Question 6

Transit:

Answer 6

Transit levels uses a telescope that can be rotated up and down as well as side to side. It can be used to measure vertical angels. It can also determine if post or wall is plumb

Question 7

How are transits classified?

Answer 7

The smallest increment that can be read on its vernier scale. Which are in Minutes or in seconds.

Question 8

Theodolite:

Answer 8

a transit that reads horizontal and vertical angles electronically. It needs no vernier scale. Used for extremely accurate measurements.

Question 9

To lay out a building using a transit or a level, you must first have a basic starting point. This starting point is usually called

Answer 9

the Bench Mark or Point of reference. This may be a mark on the foundation of a nearby building. More often it is a stone or concrete marker placed on the ground at a certain locations.

Question 10

Where should you set up a transit?

Answer 10

Outside the flow of activities on a job site.

Question 11

Station Mark:

Answer 11

Point over which a level is directly centered. The layout is sighted from this point. It may be a bench mark or corner of the lot, but should be where lot can be conveniently sighted.

Question 12

How do you center the level or transit directly over the station mark?

Answer 12

Suspend a plumb bob from a hook beneath the head of the instrument.

Question 13

Adjust the tripod so that it:

Answer 13

rests firmly on the ground with telescope at eye level.

Question 14

Excavation:

Answer 14

cut, cavity, trench, or depression made by removing earth.

Question 15

Sometimes the bench mark is used as a reference point for

Answer 15

establishing the grade.

Question 16

If the grade is not established by the bench mark, the grade may be located in relation to the level of

Answer 16

an existing street or curb.

Question 17

The grade is indicated on

Answer 17

a stake driven into the ground outside the excavation area.

Question 18

You can use the grade to establish:

Answer 18

other points such as the height of a foundation or the elevation of the first floor.

Question 19

After the grade and corners of the house has been established:

Answer 19

, building lines must be laid out as aids in keeping the work level and true.

Question 20

A batter board

Answer 20

is a board fastened horizontally to stakes placed outside of where the corners of the building will be located.

Question 21

The boards and the strings tied between the batter board:

Answer 21

locate and mark the outline of the building.

Question 22

The height of the batter boards may be:

Answer 22

the height of the foundation wall.

Question 23

Before setting up the batter boards:

Answer 23

locate the corner of the building precisely by one of the methods already disused.

Question 24

To be certain that the corners of a batter board are square:

Answer 24

1. Measure the diagonals of the completed layout to see if they are the same length.
2. use the 3-4-5 method. Measure the distance along one side in 3’ increments such as 3, 6, 9 or 12.
3. Measure along the adjoining side in the same number of 4’ increments (8, 12, or 16). The diagnal drawn between the end points will then measure an equal number of 5’ units when square.

Question 25

After the buildings location and alignment have been determined:

Answer 25

a rectangle showing the outer dimensions of a structure is staked out.