Lesson A3-6 Planning, Laying Out, and Tooling Concrete Block.

Lesson A3-6Lesson A3-6

Planning, Laying Out, and Planning, Laying Out, and Tooling Concrete BlockTooling Concrete Block

Problem Area 3.Problem Area 3.

Construction SystemsConstruction Systems

Lesson 6.Lesson 6.

Planning, Laying Out, and Planning, Laying Out, and Tooling Concrete BlockTooling Concrete Block

Student Learning ObjectivesStudent Learning Objectives

Discuss how to plan and lay out a Discuss how to plan and lay out a job.job.

Explain how to mix mortar and lay Explain how to mix mortar and lay blocks.blocks.

Explain how to tool joints, patch Explain how to tool joints, patch holes, and clean smears.holes, and clean smears.

TerminologyTerminologyBatter boardsBatter boards

Block chiselBlock chisel

Block hammerBlock hammer

Block trowelBlock trowel

Closure blockClosure block

Concrete masonry unitsConcrete masonry units

Corner blockCorner block

Face shell mortar bedFace shell mortar bed

Frost lineFrost line

Full mortar bedFull mortar bed

JointerJointer

Lightweight blocksLightweight blocks

Mason’s lineMason’s line

Masonry cementMasonry cement

Masonry sandMasonry sand

MortarMortar

Mortar hoeMortar hoe

Raker jointRaker joint

Standard or heavyweight Standard or heavyweight blocksblocks

Story or course poleStory or course pole

Stretcher blockStretcher block

Tooling jointsTooling joints

Anticipated Problem:Anticipated Problem:

How can I plan and lay out a How can I plan and lay out a concrete masonry job?concrete masonry job?

Concrete masonryConcrete masonry

Popular type of agricultural Popular type of agricultural construction. construction.

Concrete blocks are strong, Concrete blocks are strong, durable, fireproof, rodent and durable, fireproof, rodent and termite proof, and do not rottermite proof, and do not rot

Concrete masonry units, also called Concrete masonry units, also called concrete blocks, come in two types concrete blocks, come in two types and several standard sizesand several standard sizes

General TypesGeneral Types

Two general types:Two general types:–hollow hollow

–solidsolid

Standard or heavyweight block: Standard or heavyweight block: –Made from Portland cement, water, Made from Portland cement, water,

sand, gravel, and crushed stonesand, gravel, and crushed stone

General TypesGeneral Types

Lightweight blocks:Lightweight blocks:–Made from Portland cement, water, Made from Portland cement, water,

and lightweight aggregates, such as and lightweight aggregates, such as cinders, slag, or shale. cinders, slag, or shale.

–Weighs half as much as a standard Weighs half as much as a standard blockblock

–Easier to handle but have greater Easier to handle but have greater insulating valueinsulating value

Block SizesBlock SizesEven number widthsEven number widths–4, 6, 8, 10, and 12 inches 4, 6, 8, 10, and 12 inches

Even number heights Even number heights –4 and 8 inches4 and 8 inches

8 ×8 ×16 block8 ×8 ×16 block–Widely used to build agricultural Widely used to build agricultural

structures.structures.–Actual dimensions are: Actual dimensions are: 7 7 5 /85 /8 ×7 ×7 5 /85 /8 ×15 ×15 5 /85 /8

Block SizesBlock Sizes

When the standard 3/8 mortar joint When the standard 3/8 mortar joint is added, the block with one mortar is added, the block with one mortar joint is 8 inches high and 16 inches joint is 8 inches high and 16 inches long.long.

Pictures Courtesy of Interstate Publishers, Inc

Block Types Block Types

Building dimensionsBuilding dimensions–Total length and width in inches Total length and width in inches

should be divisible by eight so that full should be divisible by eight so that full blocks and half blocks will be usedblocks and half blocks will be used

Blocks come in a variety of shapesBlocks come in a variety of shapes–Corner block and stretcher blocks are Corner block and stretcher blocks are

the most commonthe most common

Block TypesBlock Types

Stretcher block: has ribs on both Stretcher block: has ribs on both ends ends –Usually with three cores or holes in Usually with three cores or holes in

the blockthe block

–Used between the cornersUsed between the corners


Block TypesBlock Types

Corner block: Square across one Corner block: Square across one end and has ribs on the other endend and has ribs on the other end–Used at the corner when laying blocks Used at the corner when laying blocks

Use the dimensions to figure theUse the dimensions to figure the

Use the dimensions to figure the Use the dimensions to figure the number of blocks needed.number of blocks needed.


Other BlocksOther Blocks


Bonding MaterialsBonding Materials

Mortar: Bonding material made of Mortar: Bonding material made of sand and masonry cementsand and masonry cement–Mix one part cement to 2½ to 3 parts Mix one part cement to 2½ to 3 parts

masonry sand. masonry sand.

Masonry cement: Type of cement Masonry cement: Type of cement used to make mortar while Portland used to make mortar while Portland cement is used to make concretecement is used to make concrete

Bonding MaterialsBonding Materials

Masonry sand is fine sand while the Masonry sand is fine sand while the sand used in concrete is coarse sand used in concrete is coarse sandsand

Use the following as a guide to Use the following as a guide to calculate the amount of cement and calculate the amount of cement and sand to purchase: sand to purchase: –in a 1:3 mix, 1 bag of cement and 250 in a 1:3 mix, 1 bag of cement and 250

pounds of sand will lay 100 eight inch pounds of sand will lay 100 eight inch blocks.blocks.

Laying out the StructureLaying out the Structure

Building must be laid out prior to Building must be laid out prior to digging the footing and pouring itdigging the footing and pouring it

Surveying instrumentsSurveying instruments–Easiest, quickest, most accurate way Easiest, quickest, most accurate way

to lay out building’s cornersto lay out building’s corners

Generally laid out parallel to Generally laid out parallel to property lines or other buildingsproperty lines or other buildings

Laying out the StructureLaying out the Structure

Surveying level and target rod:Surveying level and target rod:–Helps to set square corners and the Helps to set square corners and the

proper height of the foundation wallproper height of the foundation wall

Dimensions should always be Dimensions should always be doubled checkeddoubled checked

Measuring for equal diagonals is a Measuring for equal diagonals is a way to check for square corners.way to check for square corners.

If no Surveying EquipmentIf no Surveying Equipment

Establish a base line and use the 3–Establish a base line and use the 3–4–5 right triangle method to 4–5 right triangle method to establish square cornersestablish square corners

Outer SupportsOuter SupportsBatter boards: Outside supports Batter boards: Outside supports used to stretch stringsused to stretch strings–stretch strings: set up when corner stretch strings: set up when corner

stakes are in placestakes are in place

–The batter board includes three stakes The batter board includes three stakes and two horizontal 1 x 4 or 1 x 6’sand two horizontal 1 x 4 or 1 x 6’s

–The strings mark the outside of the The strings mark the outside of the foundation wall and the top of the foundation wall and the top of the foundationfoundation

Outer SupportsOuter Supports

Plumb bobs can be helpful to insure Plumb bobs can be helpful to insure that the strings intersect over the that the strings intersect over the corner stakecorner stake

Use powdered lime or spray paint to Use powdered lime or spray paint to mark the ground for digging the mark the ground for digging the footingfooting


Remove strings while the digging is Remove strings while the digging is done. done.

The surveying level and the target The surveying level and the target rod are used to set the grade stakes rod are used to set the grade stakes or forms in the trenchor forms in the trench


The footing trench should be dug The footing trench should be dug down to firm soil below the frost linedown to firm soil below the frost line–Frost line: Deepest point in the soil Frost line: Deepest point in the soil

where the ground freezes in a typical where the ground freezes in a typical yearyear

–The bottom of the trench should be The bottom of the trench should be flat and levelflat and level


Footing rules are:Footing rules are:–Set at or below the frost line, Set at or below the frost line,

–pour a minimum of 8 inches for 8 inch pour a minimum of 8 inches for 8 inch blocks, 10 inches for 10 inch blocks, blocks, 10 inches for 10 inch blocks, etc., and etc., and

–have the footing at least twice as wide have the footing at least twice as wide as the foundation.as the foundation.


After footing is poured and forms After footing is poured and forms are removed:are removed:–Sweep off the footing and re-stretch Sweep off the footing and re-stretch

the strings the strings

The plumb bob can be used at the The plumb bob can be used at the string intersection to help mark the string intersection to help mark the corners on the footingcorners on the footing


Snap a chalk line on the concrete Snap a chalk line on the concrete footing to mark the location of the footing to mark the location of the outside of the first row of concrete outside of the first row of concrete blocksblocks

Beginning block layers sometimes Beginning block layers sometimes lay out the first row of blocks without lay out the first row of blocks without mortar to make sure the layout was mortar to make sure the layout was planned properlyplanned properly



How is mortar mixed and How is mortar mixed and blocks laid?blocks laid?

Mixing Mortar and Laying BlocksMixing Mortar and Laying Blocks

Good mortar: Absolutely necessary Good mortar: Absolutely necessary for good workmanship and a good for good workmanship and a good finished wallfinished wall

Process of laying concrete blocks Process of laying concrete blocks requires considerable know-how requires considerable know-how and skilland skill

Concrete masonry work may be Concrete masonry work may be contracted to professionalscontracted to professionals

Concrete MasonryConcrete Masonry

You start by mixing mortar and You start by mixing mortar and carrying blockscarrying blocksStart with:Start with:–Clean, dry blocks Clean, dry blocks –waterwater–masonry sandmasonry sand–masonry cementmasonry cement–concrete blocksconcrete blocks–quality toolsquality tools

Mixing Mortar Mixing Mortar

Strength of a mortar joint is affected Strength of a mortar joint is affected by:by:–Quantity of cementing material,Quantity of cementing material,

–Portions and moisture content of the Portions and moisture content of the mortar, andmortar, and

–Quality of the workmanship. Quality of the workmanship.

Mixing MortarMixing Mortar

Mix one part masonry cement to 2½ Mix one part masonry cement to 2½ to 3 parts masonry sand with to 3 parts masonry sand with enough to make a workable mix that enough to make a workable mix that is plastic enough to support blocks is plastic enough to support blocks on a 3 /8 inch mortar joint until it has on a 3 /8 inch mortar joint until it has setset–If masonry cement is not available: If masonry cement is not available:

Use Combination of Portland cement Use Combination of Portland cement and hydrated limeand hydrated lime


Mix mortar in:Mix mortar in:–A leakproof box with shallow sides,A leakproof box with shallow sides,

–A wheelbarrow, or A wheelbarrow, or

–A mixing machineA mixing machine


To hand mix:To hand mix:–Use a mortar hoe (a hoe with two Use a mortar hoe (a hoe with two

large holes in the blade) to dry mix the large holes in the blade) to dry mix the cement and sand until a uniform color cement and sand until a uniform color exists. exists.

–Gradually add water and continue Gradually add water and continue mixing with the mortar hoe until the mixing with the mortar hoe until the mortar is plastic and workablemortar is plastic and workable


If mortar is:If mortar is:–Too stiff: Will not bond well and Too stiff: Will not bond well and

results in a thick jointresults in a thick joint

–Too thin: Will be squeezed out by the Too thin: Will be squeezed out by the weight of the block resulting in narrow weight of the block resulting in narrow mortar jointsmortar joints


Concrete LayoutConcrete LayoutLocate the corners and lay out the Locate the corners and lay out the first course, without mortar, to check first course, without mortar, to check the layoutthe layout

Full mortar bed: Using mortar on both Full mortar bed: Using mortar on both horizontal and vertical cross webs of horizontal and vertical cross webs of the blockthe block

Face shell mortar bed: Using mortar Face shell mortar bed: Using mortar on only the horizontal cross webs of on only the horizontal cross webs of the blockthe block

Concrete LayoutConcrete Layout

Normally the first course uses a full Normally the first course uses a full mortar bed and the other courses mortar bed and the other courses use a face shell mortar beduse a face shell mortar bed

Always lay the blocks with the Always lay the blocks with the thicker end of the face shell up thicker end of the face shell up –This provides a larger area on which This provides a larger area on which

to place the mortarto place the mortar

Laying first course of Blocks Laying first course of Blocks

Mason’s line: Nylon string that is Mason’s line: Nylon string that is stretched tight to mark the top and stretched tight to mark the top and outside edge of a row of concrete outside edge of a row of concrete blocksblocks–Once the first course corner blocks Once the first course corner blocks

are laid in position stretch it so that are laid in position stretch it so that the first course will be straightthe first course will be straight

Buttering refers to putting mortar on Buttering refers to putting mortar on the end of a blockthe end of a block

Laying first course of BlocksLaying first course of Blocks

Block layers often stand several Block layers often stand several blocks on end and butter the endsblocks on end and butter the ends

To get a better bond to the block:To get a better bond to the block:–Flip mortar off trowel onto block with Flip mortar off trowel onto block with

snap of the wristsnap of the wrist

To place the block in position:To place the block in position:–Pick it up with both hands and use a Pick it up with both hands and use a

swinging motion to lower it into positionswinging motion to lower it into position




To make sure a laid block is level To make sure a laid block is level plumb, and aligned:plumb, and aligned:–Use a levelUse a level

–Level the blocks by tapping the block Level the blocks by tapping the block with the handle of the trowelwith the handle of the trowel




Block trowel: Triangular shaped Block trowel: Triangular shaped piece of metal with a wooden piece of metal with a wooden handle handle

Block hammer: Can be used to tap Block hammer: Can be used to tap blocks into place as well as cutting blocks into place as well as cutting blocksblocks


Block chisel: Three or four inch wide Block chisel: Three or four inch wide metal chisel that can be hit with the metal chisel that can be hit with the block hammer to mark and cut block hammer to mark and cut concrete blocksconcrete blocks

After first course of blocksAfter first course of blocks

Use face shell mortar beds and lay Use face shell mortar beds and lay up 4 or 5 courses of blocks at the up 4 or 5 courses of blocks at the cornerscorners

Check for each block’s:Check for each block’s:–Level, plumb, and alignment Level, plumb, and alignment

Checking horizontal spacing:Checking horizontal spacing:–Use a straightedge or four foot level Use a straightedge or four foot level


Since each course is back spaced a Since each course is back spaced a half block, the corner of each back half block, the corner of each back stepped row should touch the stepped row should touch the diagonally positioned straightedge.diagonally positioned straightedge.

Story or course pole: Board with Story or course pole: Board with markings eight inches apartmarkings eight inches apart–Use to ensure that the horizontal Use to ensure that the horizontal

mortar jointings are running 3 /8 mortar jointings are running 3 /8 inches thick.inches thick.


Key to a straight true wall:Key to a straight true wall:–Using the mason’s line between the Using the mason’s line between the

corners as a guidecorners as a guide

Most difficult part of laying blocks:Most difficult part of laying blocks:–Usually laying the closure blockUsually laying the closure block


Closure block: Last block laid to Closure block: Last block laid to complete the rowcomplete the row

If vertical mortar joints have been If vertical mortar joints have been 3/83/8 inches the opening for the last inches the opening for the last block should be 16 block should be 16 3/83/8 inches long inches long (2 (2 3/83/8 inch mortar joints and a 15 inch mortar joints and a 15 5/8 5/8 inch block)inch block)


Closure block:Closure block:–Must be buttered on both ends orMust be buttered on both ends or

–Previously laid block must be buttered Previously laid block must be buttered

– If mortar falls off the end of the block If mortar falls off the end of the block as swung into place, block should be as swung into place, block should be removed and re-butteredremoved and re-buttered


How are mortar joints tooled How are mortar joints tooled and smears removed?and smears removed?

Tooling joints and removing Tooling joints and removing smearssmears

Completes job resulting in a Completes job resulting in a professional appearance to the jobprofessional appearance to the job

Tooling JointsTooling Joints

Procedure that pushes the mortar Procedure that pushes the mortar into the groove between the blocksinto the groove between the blocks–Creating an improved bond of the Creating an improved bond of the

mortar to the blockmortar to the blockResults in a weather-tight joint with a Results in a weather-tight joint with a neat appearanceneat appearance

Jointer: Concave or V-shaped metal Jointer: Concave or V-shaped metal tool with a handle and turned up tool with a handle and turned up endsends

Tooling JointsTooling Joints

Brick layers often use a raker joint.Brick layers often use a raker joint.

Raker joint: Tool that moves the Raker joint: Tool that moves the mortar from the joint to depth of mortar from the joint to depth of approximately 3/8 inchesapproximately 3/8 inches

Removing mortar burrsRemoving mortar burrs

After joints have been tooled, trim After joints have been tooled, trim off with face of the wall with the off with face of the wall with the troweltrowel

Crooked BlocksCrooked Blocks

Do not attempt to move or Do not attempt to move or straighten the block once the mortar straighten the block once the mortar has stiffened or even partly stiffenedhas stiffened or even partly stiffened

Patching and Filling Joints and Patching and Filling Joints and HolesHoles

Should be done with fresh mortarShould be done with fresh mortar

Mortar DabsMortar Dabs

On block:On block:–Should be allowed to dryShould be allowed to dry

Use trowel to knock dab off Use trowel to knock dab off

Piece of a concrete block to rub out Piece of a concrete block to rub out remaining particlesremaining particles

Smears Smears

When laying blocks, be careful not When laying blocks, be careful not to smear mortar into the blocksto smear mortar into the blocks

Once the smears are in the block it Once the smears are in the block it is impossible to remove themis impossible to remove them

Muriatic acid rinse will help clean Muriatic acid rinse will help clean the wall and make paint smears the wall and make paint smears less noticeableless noticeable

Review / SummaryReview / Summary

Discuss how to plan and lay out a Discuss how to plan and lay out a job.job.

Explain how to mix mortar and lay Explain how to mix mortar and lay blocks.blocks.

Explain how to tool joints, patch Explain how to tool joints, patch holes, and clean smears.holes, and clean smears.

Lesson A3-6 Planning, Laying Out, and Tooling Concrete Block.

Documents

concrete slide

block types corner block

tooling concrete block

block types stretcher

block sizes

concrete blocks

common slide

standard block easier