Deck 38: Construction of a Jack Arch

Question 1

Skewbacks are either cut with a sharp brick chisel or cut with the brick saw for accuracy.

Answer 1

True

Question 2

A jack arch is a flat arch capable of supporting a load imposed on it over an opening.

Answer 2

True

Question 3

It is recommended that the thickness of mortar joints between arch brick be a _____ .

A) minimum of ¼"
B) maximum of ¼"
C) minimum of ½"
D) maximum of ½"

Answer 3

B

Question 4

A jack arch that is built correctly gives the appearance of sagging in the center.

Question 5

Jack arches can be built only over tapered or sawn brick.

Question 6

A _____ does a nice job of pointing the jack arch.

A) small trowel
B) beader
C) slicker
D) rake

Question 7

When laying the jack arch, the mortar should be mixed stiff enough that it does not squeeze out when laid, except with abundant tapping on the brick.

Question 8

A jack arch is supported on steel angle irons if the opening is _____ long.

A) less than 2'
B) more than 2'
C) between 1' and 2'
D) more than 1'

Question 9

A _____ jack arch is composed of only one full brick in height and laid in a soldier position.

A) common
B) soldier
C) single
D) bonded

Question 10

The accepted rule for determining the angle of a jack arch states that "the skewback angle should be _____ of span of the opening for each 4" of arch depth."

A) ¾' per yard
B) ½' per yard
C) ¾" per foot
D) ½" per foot