F1 - Lay out buildings

Question 1

What is one of the first steps in the construction of a building?

Answer 1

To properly lay out corner locations for the building and determine elevations.

Question 2

When the layout is tight to the allowable lot line setbacks, or if the layout is complex due to building design or other reasons, what is the solution?

Answer 2

A registered surveyor is hired to pin the building corners.

Pins are steel rods driven in AFTER excavations but before footings are constructed.

Question 3

What is the best way to ensure a square?

Answer 3

Check the measurements of the sides, then compare diagonals

Question 4

What does NG and FG stand for?

Answer 4

NG = Natural Grade
FG = Finished Grade

Question 5

What does a site survey often include?

Answer 5

Taking elevations over the entire building and digging soil tests

Question 6

What would an 11% grade be?

Answer 6

A slope with an elevation change of 11 ft over a span of 100 ft

Question 7

How are grade stakes used?

Answer 7

Driven into the ground along grid lines & marked with the amount of cut or fill needed at each stake. Normally measured from the top of the stake.

Question 8

What are the 3 methods for laying out over a sloped area.

Answer 8

1) Measure level then plumb down
2) Use Pythagoras theorem, to measure a long the slope
3) Using trig and measuring along the slope

Question 9

If the layout is square, the diagonals will be:

Answer 9

Exactly equal or within 1 or 2 mm

Question 10

The larger the triangle used in the 3-4-5 method, the more _____

Answer 10

The more precise your layout will be.

Question 11

As part of the site survey, test pits are dug, what exactly was done in that process?

Answer 11

A test pit is dug to the full depth of excavation to determine the water table heights and what type of soil will be encountered during the excavation.

Question 12

Do you immediately fill in a test pit after digging?

Answer 12

Leave the test pit open for several hours to find out if any water has seeped into the pit

Question 13

What are the two meanings of the term Grade?

Answer 13

1) Surface of the ground on the job site. (EX NG or FG)

2) Grade also means slope - a 2% grade means that the earth drops 200 mm vertically for every 100 M traveled horizontally.

Question 14

A 2% grade can be called what?

Answer 14

A 2% fall as well

Question 15

Grading elevations are often established how?

Answer 15

By referencing them to a benchmark on or near the building site.

Question 16

On large projects such as industrial sites and shopping centers, most grading takes place when?

Answer 16

Most grading takes place BEFORE excavation and a small amount of finish grading occurs AFTER the building is complete

Question 17

Grade stakes located at the corners of excavations indicate what?

Answer 17

The depths of cut

Question 18

Grade stakes are driven into the ground where?

Answer 18

At the intersection of the gridlines

Question 19

The purpose of a grade stake is what?

Answer 19

To determine where soil must be added or removed

Question 20

What does a very tall grade stake usually mean?

Answer 20

If considerable earth cutting and removal is required

Question 21

What is a screed stake used for?

Answer 21

To set the elevation of the top of the concrete

Question 22

For narrow slabs, what forms the screed usually?

Answer 22

The formwork usually forms the screed for narrow slabs

Question 23

For wider slabs of concrete, what screed application is needed?

Answer 23

Intermediate screeds in addition to the formwork

Question 24

What are screeds made from?

Answer 24

Wood or metal (usually pipe)

Question 25

When are the screeds and wooden stakes removed?

Answer 25

After the strike-off

Question 26

What is the usual spacing for screed stakes?

Answer 26

Between 6 ft and 12 ft OC

Question 27

How are screed stakes placed?

Answer 27

They are placed in a grid pattern similar to the way grade stakes are placed

Question 28

Stakes are either driven in or cut off such that the top of the stakes are even with the _________ of the top of the slab

Answer 28

Elevation

Question 29

What tool is used to determine that the tape is being held close to level using the “Plumb down” method”

Answer 29

A string line level or an optical level

Question 30

How to find the depth of slope?

Answer 30

COA = Adj divided by COS angle = depth (hypotenuse)