Unit 4 CARPENTRY - CareerTech (CT) -

Unit 4 • Measuring

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Measuring is one of the first basic skills thata carpenter should master. Accurate measurements are very important.Inaccurate measurements lead to wastedtime, materials, and money. Carpentersshould learn to use the correct measuringtools and use them properly. When doinglayout work there is no such thing as “goodenough” or “close enough.” Your measurements should be accurate.

Objectives ———————

1. Identify basic measuring tools.

2. Identify graduations on basic measuring tools.

3. Read a rule to the nearest fraction ofan inch.

4. Convert fractional inches to hundredths of a foot.

5. Read a tape to the nearest fraction ofan inch.

6. List common errors that contribute toincorrect measurements.

7. Read measurements on folding rules.(Assignment Sheet 1)

8. Measure dimensions of objects.(Assignment Sheet 2)

9. Convert fractional inches to hundredths of a foot. (Assignment Sheet 3)

10. Read measurements on tapes.(Assignment Sheet 4)

TechConnect - STUDENT WORKBOOK 4 - 1 Measuring - Unit 4

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connectUnit 4 • Measuring

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Unit 4 - Measuring 4 - 2 STUDENT WORKBOOK - TechConnect

Objective 1:——————Identify Basic MeasuringTools

100' tape – used to measure shortand long measurements with accuracy (Figure 1)

Folding rule (zigzag rule) – used tomake accurate inside and outsidemeasurements for laying out forms,laying out joints, and checking forsquare (Figure 2)

Steel tape – used to measure irregular as well as regular shapesand to make accurate inside and outside measurements (Figure 3)

FIGURE 1

FIGURE 2

FIGURE 3

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Objective 2:—————Identify Graduations on Basic Measuring Tools

The following illustrations showdifferent graduations or divisions onbasic measuring tools. ‘

FIGURE 4

It is important for a carpenter to beable to read and understand whatthese graduations mean.

The illustrations used below are onlyexamples and not all rules have thesame exact graduations shownbelow.

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Objective 3:——————Read A Rule to the Nearest Fraction of an Inch.

All rules are read similarly. However,rules may have different graduations,and some rules may have specialmarkings for specific purposes. Layoutrules, for instance, are marked every16" as an aid in determining stud locations on 16" centers.

1. Align the end of the rule with one reference point.

2. Determine the number of whole unitsbetween the end of the rule and thesecond reference point.

NOTE: The unit of measurement willvary, depending on the distancebeing measured and the use beingmade of the measurement. Mostshort measurements are made ininches, even if they are more than 1foot long. Skilled craftsmen are gen-erally able to quickly convert meas-urements from feet to inches or viceversa for distances of 10 to 12 feetor more. Thus, a carpenter mayspeak of a ceiling as 4 by 8 feet oras 48 by 96 inches.

FIGURE 5

3. Determine the number of fractionalunits between the last whole unit andthe second reference point.

a. Determine the number of gradua-tions per inch. At first you mayhave to count the number of divi-sions in an inch. However, withsome practice, you will be able torecognize the divisions on sightand will eventually be able todetermine fractional units just bylooking at the rule.

b. Determine the fractional part ofan inch by counting the numberof divisions between the last inchand the second reference point.

c. Reduce the fraction, if possible.


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NOTE: In the example, the rule is divided into sixteenths. There areten divisions betweenthe last inch mark—3"—and the referencepoint. The 10/16 canbe reduced to 5/8.(Figure 6)

4. Determine the reading by addingfractional units to whole units andconverting inches to feet or feet toinches if necessary.

EXAMPLE: The following rule showsa measurement of 1'-2 1/2" or 14 1/2". (Figure 7)

FIGURE 7

FIGURE 6


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Objective 4: ——————Convert Fractional Inchesto Hundredths of a Foot

There are two general methods used bythe industry today for converting fractional inches to hundredths of a foot.One method is to apply the formula andrules described in this section. The formula is not exact, but it is generallyaccurate enough for the requirements ofthe trade and for use with the rules that acarpenter may have. The second methodis to refer to a conversion table. See Table1.

Apply the following guidelines in the conversion process:

1. Consider each 12 inches to be equalto 1.00 foot.

2. Consider each 18 inch to be equalto 0.01 foot.

3. To allow for the difference between18 inch and 0.01 foot, add another0.01 foot for 2 inches, 0.02 foot for 5inches, 0.03 foot for 8 inches, and0.04 foot for 11 inches.

Use the following steps in the conversionprocess:

1. Write the number of whole feet as awhole number to the left of the decimal point.

2. Convert the remaining inches andfractional parts of inches to hundredths of a foot.

a. Change the inches and fractions to eighths, rounding six-teenths and thirty-seconds to thenearest eighths as necessary.

b. Multiply the numerator by 0.01.

c. Add the product of the two numbers to the whole-foot number.

3. Add the required number for quantities of 2 inches or more.

EXAMPLE 1: Convert 14'-5 1/4" tohundredths of a foot.

a. 14' = 14.00'

b. 5 1/4" = 2 1/4" = 4 2/8"

c. 42 x 0.01 = .42

d. Add 0.02 for 5 inches

e. 14.000.42

+ 0.0214.44'

EXAMPLE 2: Convert 5'-3 1/6" tohundredths of a foot.

a. 5' = 5.00'

b. 3 1/6" = 1.58"

c. 1.5/8" rounds to 2/8"

d. 2 x 0.01 = .02

e. 5.00 + 0.02

5.02'


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1/8" = .011/4" = .023/8" = .031/2" = .045/8" = .053/4" = .067/8" = .071" = .081 1/8" = .091 1/4" = .101 3/8" = .111 1/2" = .121 5/8" = .131 3/4" = .141 7/8" = .152" = .16 + .01 = .172 1/8" = .182 1/4" = .192 3/8" = .202 1/2" = .212 5/8" = .222 3/4" = .232 7/8" = .243" = .253 1/8" = .263 1/4" = .273 3/8" = .283 1/2" = .293 5/8" = .303 3/4" = .313 7/8" = .32

4" = .334 1/8" = .344 1/4" = .354 3/8" = .364 1/2" = .374 5/8" = .384 3/4" = .394 7/8" = .405" = .41 + .01 = .425 1/8" = .435 1/4" = .445 3/8"= .455 1/2" = .465 5/8" = .475 3/4" = .485 7/8" = .496" = .506 1/8" = .516 1/4" = .526 3/8" = .536 1/2" = .546 5/8" = .556 3/4" = .566 7/8" = .577" = .587 1/8" = .597 1/4" = .607 3/8" = .617 1/2" = .627 5/8" = .637 3/4" = .647 7/8" = .65

8" = .66 + .01 = .678 1/8" = .688 1/4" = .698 3/8" = .708 1/2" = .718 5/8" = .728 3/4" = .738 7/8" = .749" = .759 1/8"= .769 1/4" = .779 3/8" = .789 1/2" = .799 5/8" = .809 3/4" = .819 7/8" = .8210" = .8310 1/8" = .8410 1/4" = .8510 3/8" = .8610 1/2" = .8710 5/8" = .8810 3/4" = .8910 7/8" = .9011" = .91 + .01 = 9211 1/8" = .9311 1/4" = .9411 3/8" = .9511 1/2" = .9611 5/8" = .9711 3/4" = .9811 7/8" = .9912" = 1.00


Standard hundredths conversion

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Objective 5: ——————Read a Tape to the Nearest Fraction of an Inch.

Follow these steps in reading a tapeto the nearest fraction of an inch.

1. Place the end of the tape on onereference point.

2. Reading from the starting end ofthe tape, determine the numberof feet to the second referencepoint.

FIGURE 8

3. Determine the number of inchesbetween the last whole-footmark and the second referencepoint.

4. Determine the fractional inchesbetween the last whole-inchmark and the second referencepoint.

5. Add feet, inches, and fractions ofan inch to obtain the correctmeasurement.

EXAMPLE: The tape belowreads seventeen feet two andone half inches (17'-2 1/2") at the second reference point.(Figure 8)

http://www.asktooltalk.com/home/qanda/faq/tools/tapemeasure.htm

Visit the following site to read more about how to read atape and what all the different marks on the tape mean:


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Objective 6: ——————List Common Errors thatContribute to IncorrectMeasurements

Errors in measurement can lead to incorrect cutting and placement of construction material. It is very importantto make accurate measurements. Haveyou ever heard the saying, "measuretwice, cut once." This saying encouragesyou to be sure that your measurementsare right in the beginning before you cut.Be aware of the following errors so thatyou will avoid wasted time and materialdue to measuring and cutting errors.

Leaving slack in tape

Not laying tape flat (tape is twistedor kinked)

Not aligning tape or rule properly

Not placing end of tape or rule on reference point

Reading incorrect number

Recording incorrect number

Using wrong reference point

EXAMPLE: When reading a diagonal measurement it is important to read the same side of the tape or rule for measurement.

Making errors in mathematical computations

EXAMPLE: When converting from one unit of measurement to another

Using incorrect measuring tool for job being performed

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Assignment Sheet 1Objective 7: ——————Read Measurements on Folding Rules.

IntroductionThe first step in being able to a make accurate measurements is to become familiarwith the graduations on rules and how to read them. This assignment sheet will allowyou to practice reading measurements on rules.

InstructionsRead the rules illustrated below and write the correct readings in the blanks below therules.

0 A B C D E F G H

A. _______________ E. _______________

B. _______________ F. _______________

C. _______________ G. _______________

D. _______________ H. _______________

0 A B C D E F G H

A. _______________ E. _______________

B. _______________ F. _______________

C. _______________ G. _______________

D. _______________ H. _______________

1.

2.


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0 A B C D E F G H

A. _______________ E. _______________

B. _______________ F. _______________

C. _______________ G. _______________

D. _______________ H. _______________

3.

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Assignment Sheet 2Objective 8: —————Measure Dimensions ofObjects

IntroductionA carpenter will use measuring skills in every phase of the job. It is essential for thecarpenter to master the ability to measure and interpret measurements.

Part 1Measure the following objects using a rule graduated in sixteenths (1/16") of an inchand write your answers in the space provided.

1.

2.

A. Length = _____________

B. Height = _____________

A. Length = _____________

B. Height = _____________

A.

B.

A.

B.


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Because of the size of projects, it is usually necessary to make scale drawings ofhouses, buildings, parking lots, site work, etc. A scale drawing uses one dimension torepresent another, and all dimensions on the drawing are reduced in the same proportion. For example, using a scale in which 1" on the drawing is equal to 1' on theactual object a 4' high and 5' long object would be 4" by 5" on the drawing.

Using a scale of 1/8" equals to 1 foot, determine the dimensions represented on figure9. Write your answers in the space provided.

FIGURE 9


1. _______________ 8. _______________

2. _______________ 9. _______________

3. _______________ 10. ______________

4. _______________ 11. ______________

5. _______________ 12. ______________

6. _______________ 13. ______________

7. _______________ 14. ______________

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Assignment Sheet 3Objective 9: —————Convert Fractional Inchesto Hundredths of a Foot.

IntroductionMany rules are marked in hundredths of a foot. Often the carpenter is required to convert inch dimensions to decimal fractions of a foot. This assignment sheet will helpyou become more proficient at converting fractional inches to hundredths of a foot.

Using the three guidelines below, convert the following inch dimensions to hundredthsof a foot. Be sure to show your calculations.

Consider each 12 inches to be equal to 1.00 foot

Consider each 1/8 inch to be equal to 0.01 foot

Add 0.01 foot for 2 inches, 0.02 foot for 5 inches, 0.03 foot for 8 inches, and 0.04 foot for 11 inches

EXAMPLE: Convert 6'- 4 1/8" to hundredths of a foot.A. 6 ' = 6.00B. 4 1/8" = 33/8 = 0.33C. Add 0.01D. 6.00

0.33+ 0.01

6.34'

1. 1/4" = _____________ 2. 14'- 5 1/2" = ____________

3. 1/4" = _____________ 4. 6 5/8" = _____________

5. 1 3/8" = ____________ 6. 7'- 7 1/8" = _____________

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Objective 10: —————Read Measurements on Tapes

IntroductionThis assignment sheet will help you to develop a better knowledge of reading a tape andwill help you to read a tape quickly and efficiently. Using the procedures outlined in thisunit, read the following tapes and write the correct dimensions in the space provided.

1. ____________________

2. ____________________

3. ____________________

4. ____________________


Reference point Reference point


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Unit 4 CARPENTRY - CareerTech (CT) -