Glencoe: 22

Question 1

Nominal size of standard CMU

Answer 1

7 5/8 wide
7 5/8 wall
15 5/8 long
This allows for 3 /8 mortar joint

Question 2

Head joint:

Bed Joint:

Answer 2

A vertical mortar joint

Horizontal mortar joint

Question 3

Which is stronger

3 core or 2 core CMU

Answer 3

3 core

Question 4

Most common types of CMUs

Answer 4

Stretcher (3core)
Corner
Stretcher (2core)

Question 5

Specialty CMU blocks:

Answer 5

Split face - one side looks like stone
Insulated blocks - contain polystyrene, reduces heat transfer between blocks
Glazed surface blocks.

Question 6

Common bond:

Answer 6

Block courses are laid in a common bond. Which is an overlapping arrangement.

Question 7

Full bedding:

Answer 7

Mortar should be spread fully on all contact surfaces of the block

Question 8

Joints should be X between CMUs

Answer 8

tooled smooth to seal them against water seepage.

Question 9

Stack Bond pattern

Answer 9

blocks are placed directly above one another

Question 10

Story pole (course pole)

Answer 10

Board with markings 8” apart. It can be used to gauge the top of the masonry for each course.

Question 11

Two common joint tooling types to be used unless otherwise specified

Answer 11

V-joint and Concave joint
V-joint is an indent that looks like the letter V from the side
Concave looks like a half circle impressed into the joint

Question 12

When is tooling done to mortar joints:

Answer 12

When the mortar has become thumb print hard (when the thumb leaves no thumb print when pressed into mortar)

Question 13

Tooling:

Answer 13

Process of using shaped metal bars to compact the mortar and force it tightly against the masonry on each side of the joint.

Question 14

Which order should tooling be done:

Answer 14

head joints first using a small S-Shaped jointer, then the bed joints.

Question 15

Estimating block wall material:

Answer 15

When estimating materials for block walls you must consider the number of blocks, the amount of mortar, and the cost of labor.

The number of blocks needed for a foundation can be determined by the area of each wall to be built.

Get the total wall area in square feet. Divide by 8 then multiply that by 9.
25' x 40' with 7' high walls.
25*2 + 40 * 2 = 130'
130' * 7 = 910
910 / 8 = 113.75
113.75 * 9 = 1,024 blocks

Alternative way: get the total square feet of wall and divide by (128 / 144). because 1 std. block is 0.88… sq feet

Question 16

1 sq. ft is X sq. in.

Answer 16

144 sq. in

Question 17

After the walls are complete, additional steps should be taken to ensure they X

Answer 17

are able to resist moisture. In some cases, block walls can be assembled using surface bonding techniques

Question 18

Like concrete walls, block walls must either be

Answer 18

dampproofed or water proofed

Question 19

Parging:

Answer 19

process of spreading mortar or cement plaster over the block to block water infiltration.

Question 20

How thick should parging be:

Answer 20

3/8”

Question 21

What do you do when parging is dry?

Answer 21

coating of asphalt is applied to the exterior side of the wall. This along with properly designed footing drain will normally ensure a dry basement

Question 22

When added protection is needed to block wall, such as when soil is wet:

Answer 22

The entire wall should be waterproofed like a solid concrete foundation

Question 23

When must a lintel be installed?

Answer 23

Where openings occur in the foundation.

Question 24

Lintel:

Answer 24

horizontal member that supports the weight of the wall above. A lintel in a masonry wall is like a header in a wood frame wall. It directs loads around the opening.

Question 25

Ways to create a lintel:

Answer 25

L-shaped steel angles
Reinforced pre-cast concrete placed over an opening as a wood header would be placed.
Lintel blocks, which are temporarily supported over the opening by a wood framework. The open portions of the blocks are filled with concrete and rebar. When concrete has cured, the wood framework can be removed.