lesson a3-6 planning, laying out, and tooling concrete block
TRANSCRIPT
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
Pictures Courtesy of Interstate Publishers, Inc
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.
Pictures Courtesy of Interstate Publishers, Inc
Other BlocksOther Blocks
Pictures Courtesy of Interstate Publishers, Inc
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
Outer SupportsOuter Supports
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
Outer SupportsOuter Supports
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
Outer SupportsOuter Supports
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.
Outer SupportsOuter Supports
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
Outer SupportsOuter Supports
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
Pictures Courtesy of Interstate Publishers, Inc
Anticipated Problem:Anticipated Problem:
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
Mixing MortarMixing Mortar
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
Mixing MortarMixing Mortar
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
Mixing MortarMixing Mortar
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
Pictures Courtesy of Interstate Publishers, Inc
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
Pictures Courtesy of Interstate Publishers, Inc
Pictures Courtesy of Interstate Publishers, Inc
Laying first course of BlocksLaying first course of Blocks
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
Pictures Courtesy of Interstate Publishers, Inc
Pictures Courtesy of Interstate Publishers, Inc
Laying first course of BlocksLaying first course of Blocks
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
Laying first course of BlocksLaying first course of Blocks
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
After first course of blocksAfter first course of blocks
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.
After first course of blocksAfter first course of blocks
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
After first course of blocksAfter first course of blocks
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)
After first course of blocksAfter first course of blocks
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
Anticipated Problem:Anticipated Problem:
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.