 Planning,
Laying Out, and
Tooling Concrete Block
Next Generation Science/Common Core Standards Addressed!

CCSS.ELA Literacy. RST.9‐10.3 Follow precisely a complex multistep procedure
when carrying out experiments, taking measurements, or performing technical
tasks, attending to special cases or exceptions defined in the text.

CCSS.ELA Literacy. RST.9‐ 10.5Analyze the structure of the relationships among
concepts in a text, including relationships among key terms (e.g., force, friction,
reaction force, energy).

CCSS.ELA Literacy. RST.11‐ 12.3 Follow precisely a complex multistep procedure
when carrying out experiments, taking measurements, or performing technical
tasks; analyze the specific results based on explanations in the text

CCSS.ELA Literacy. RST.11‐12.4 Determine the meaning of symbols, key terms, and
other domain‐specific words and phrases as they are used in a specific scientific
or technical context relevant to grades 11–12 texts and topics.

CCSS.Math.Content.HSGCO.D.12 Make formal geometric constructions with a
variety of tools and methods (compass and straight edge, string, reflective
devices, paper folding, dynamic geometric software, etc.). Copying a segment;
copying an angle; bisecting a segment; bisecting an angle; constructing
perpendicular lines, including the perpendicular bisector of a line segment; and
constructing a line parallel to a given line through a point not on the line
Bell Work/Student Learning Objectives
 Discuss
how to plan and lay out a job.
 Explain
how to mix mortar and lay blocks.
 Explain
how to tool joints, patch holes, and
clean smears.
Terminology

Batter boards

Mason’s line

Block chisel

Masonry cement

Block hammer

Masonry sand

Block trowel

Mortar

Closure block

Mortar hoe

Concrete masonry units

Raker joint

Corner block


Face shell mortar bed
Standard or heavyweight
blocks

Frost line

Story or course pole

Full mortar bed

Stretcher block

Jointer

Tooling joints

Lightweight blocks
Concrete masonry

Popular type of agricultural construction.

Concrete blocks are strong, durable,
fireproof, rodent and termite proof, and
do not rot

Concrete masonry units, also called
concrete blocks, come in two types and
several standard sizes
General Types

Two general types:
 hollow
 solid

Standard or heavyweight block:
 Made
from Portland cement,
water, sand, gravel, and
crushed stone
General Types

Lightweight blocks:
 Made
from Portland cement, water,
and lightweight aggregates, such as
cinders, slag, or shale.
 Weighs
half as much as a standard
block
 Easier
to handle but have greater
insulating value
Block Sizes

Even number widths
 4,

Even number heights
4

6, 8, 10, and 12 inches
and 8 inches
8 ×8 ×16 block
 Widely
used to build agricultural structures.
 Actual
dimensions are: 7 5 /8 ×7 5 /8 ×15 5 /8
 Mortar
completes the dimensions (3/8 layer)
Block Sizes

When the standard 3/8 mortar joint
is added, the block with one mortar
joint is 8 inches high and 16 inches
long.
Block Types

Building dimensions
 Total
length and width in inches should
be divisible by eight so that full blocks
and half blocks will be used

Blocks come in a variety of shapes
 Corner
block and stretcher blocks are
the most common
Block Types

Stretcher block: has ribs on both ends
 Usually
with three cores or holes in the
block
 Used
between the corners
Block Types

Corner block: Square across one end and has ribs
on the other end


Used at the corner when laying blocks Use the
dimensions to figure the
Use the dimensions to figure the number of blocks
needed.
Other types of blocks!
Bonding Materials

Mortar: Bonding material made of
sand and masonry cement
 Mix
one part cement to 2½ to 3
parts masonry sand.

Masonry cement: Type of cement
used to make mortar while Portland
cement is used to make concrete
Bonding Materials

Masonry sand is fine sand while the
sand used in concrete is coarse sand

Use the following as a guide to
calculate the amount of cement
and sand to purchase:
 in
a 1:3 mix, 1 bag of cement and
250 pounds of sand will lay 100
eight inch blocks.
Laying out the Structure


Building must be laid out
prior to digging the footing
and pouring it
Surveying instruments
 Easiest,
quickest, most
accurate way to lay out
building’s corners

Generally laid out parallel
to property lines or other
buildings
Laying out the Structure

Surveying level and target rod:
Helps to set square corners and
the proper height of the
foundation wall
Dimensions should always be
doubled checked
Measuring for equal diagonals is
a way to check for square
corners.
If no Surveying Equipment

Establish a base line and use the 3–4–5 right
triangle method to establish square corners
Outer Supports

Batter boards: Outside supports used to stretch strings
 stretch
strings: set up when corner stakes are in place
 The
batter board includes three stakes and two
horizontal 1 x 4 or 1 x 6’s
 The
strings mark the outside of the foundation wall and
the top of the foundation
Outer Supports

Plumb bobs can be helpful to insure that
the strings intersect over the corner stake

Use powdered lime or spray paint to mark
the ground for digging the footing
Outer Supports
 Remove
strings while the
digging is done.
 The
surveying level and the
target rod are used to set the
grade stakes or forms in the
trench
Outer Supports

The footing trench should be dug down to firm soil
below the frost line

Frost line: Deepest point in the soil where the
ground freezes in a typical year

The bottom of the trench should be flat and
level

Most New Mexico building codes require the
footing to be a foot deep.
Outer Supports

Footing rules are:
 Set
at or below the frost line,
 pour
a minimum of 8 inches for 8 inch
blocks, 10 inches for 10 inch blocks,
etc., and
 have
the footing at least twice as wide
as the foundation.
Outer Supports

After footing is poured and forms are removed:

Sweep off the footing and re-stretch the
strings

The plumb bob can be used at the string
intersection to help mark the corners on the
footing

This provides you with a straight line for laying the
block wall
Outer Supports

Snap a chalk line on the concrete footing
to mark the location of the outside of the
first row of concrete blocks

Beginning block layers sometimes lay out
the first row of blocks without mortar to
make sure the layout was planned
properly
Mixing Mortar and Laying
Blocks

Good mortar: Absolutely necessary for
good workmanship and a good finished
wall

Process of laying concrete blocks requires
considerable know-how and skill

Concrete masonry work may be
contracted to professionals
Concrete Masonry

You start by mixing mortar and carrying blocks

Start with:

Clean, dry blocks

water

masonry sand

masonry cement

concrete blocks

quality tools
Mixing Mortar

Strength of a mortar joint is affected by:
 Quantity
of cementing material,
 Portions
and moisture content of the
mortar, and
 Quality
of the workmanship.
Mixing Mortar

Mix one part masonry cement to 2½ to 3
parts masonry sand with enough to make
a workable mix that is plastic enough to
support blocks on a 3 /8 inch mortar joint
until it has set
 If
masonry cement is not available:
 Use
Combination of Portland
cement and hydrated lime
Mixing Mortar

Mix mortar in:
A
leak proof box with shallow
sides,
A
wheelbarrow, or
A
mixing machine
Mixing Mortar

To hand mix:
 Use
a mortar hoe (a hoe with two large
holes in the blade) to dry mix the
cement and sand until a uniform color
exists.
 Gradually
add water and continue
mixing with the mortar hoe until the
mortar is plastic and workable
Mixing Mortar

If mortar is:
 Too
stiff: Will not bond well and
results in a thick joint
 Too
thin: Will be squeezed out by
the weight of the block resulting
in narrow mortar joints
Concrete Layout

Locate the corners and lay
out the first course,
without mortar, to check
the layout

Full mortar bed: Using
mortar on both horizontal
and vertical cross webs of
the block

Face shell mortar bed:
Using mortar on only the
horizontal cross webs of
the block
Concrete Layout

Normally the first
course uses a full
mortar bed and the
other courses use a
face shell mortar bed

Always lay the blocks
with the thicker end of
the face shell up
 This
provides a
larger area on
which to place the
mortar
Laying first course of Blocks

Mason’s line: Nylon string that is stretched tight to
mark the top and outside edge of a row of
concrete blocks


Once the first course corner blocks are laid in
position stretch it so that the first course will
be straight
Buttering refers to putting mortar on the end of a
block
Laying first course of Blocks

Block layers often stand several
blocks on end and butter the
ends

To get a better bond to the
block:
 Flip
mortar off trowel onto
block with snap of the wrist

To place the block in position:
 Pick
it up with both hands and
use a swinging motion to
lower it into position
Laying first course of Blocks

To make sure a laid block is level plumb, and
aligned:
 Use
a level
 Level
the blocks by tapping the block
with the handle of the trowel
Laying first course of Blocks

Block trowel: Triangular shaped piece of metal
with a wooden handle

Block hammer: Can be used to tap blocks into
place as well as cutting blocks
Laying first course of Blocks

Block chisel: Three or four inch wide metal chisel that can
be hit with the block hammer to mark and cut concrete
blocks
After first course of blocks

Use face shell mortar beds and lay up 4 or
5 courses of blocks at the corners

Check for each block’s:
 Level,

plumb, and alignment
Checking horizontal spacing:
 Use
a straightedge or four foot level
After first course of blocks

Since each course is back
spaced a half block, the
corner of each back
stepped row should touch
the diagonally positioned
straightedge.

Story or course pole:
Board with markings eight
inches apart
 Use
to ensure that the
horizontal mortar
jointing are running 3
/8 inches thick.
After first course of blocks

Key to a straight true wall:
 Using
the mason’s line between the
corners as a guide

Most difficult part of laying blocks:
 Usually
laying the closure block
After first course of blocks
 Closure
block: Last block laid to complete
the row
 If
vertical mortar joints have been 3/8
inches the opening for the last block should
be 16 3/8 inches long (2 3/8 inch mortar
joints and a 15 5/8 inch block)
After first course of blocks

Closure block:
 Must
be buttered on
both ends or
 Previously
laid block
must be buttered
 If
mortar falls off the
end of the block as
swung into place, block
should be removed and
re-buttered
Tooling joints and removing
smears

Completes job resulting in a professional
appearance to the job
Tooling Joints

Procedure that pushes the
mortar into the groove
between the blocks

Creating an improved
bond of the mortar to
the block
 Results
in a
weather-tight joint
with a neat
appearance

Jointer: Concave or Vshaped metal tool with a
handle and turned up ends
Tooling Joints

Brick layers often use a raker joint.

Raker joint: Tool that moves the mortar
from the joint to depth of approximately
3/8 inches
Removing mortar burrs

After joints have been tooled, trim
off with face of the wall with the
trowel
Crooked Blocks

Do not attempt to move or
straighten the block once the
mortar has stiffened or even partly
stiffened
Mortar Dabs

On block:
 Should
be allowed to dry

Use trowel to knock dab off

Piece of a concrete block to rub out
remaining particles
Smears

When laying blocks, be careful not to
smear mortar into the blocks

Once the smears are in the block it is
impossible to remove them

A wire brush will help but is unable to
remove mortar from pores in the block

Muriatic acid rinse will help clean the
wall and make paint smears less
noticeable
Review / Summary

Discuss how to plan and lay out a
job.

Explain how to mix mortar and lay
blocks.

Explain how to tool joints, patch
holes, and clean smears.
The end!