Construction Estimating

Be the first to review this product

$49.50

This unusually well-organized book shows the best and easiest way to estimate materials for room additions or residential structures. It gives estimating tables and procedures needed to make a fast, accurate, and complete material list of the structural members found in wood and steel-framed buildings.



This book is divided into 72 units, each of them covering a separate element in the estimating procedure. Covers estimating foundations, floor framing, wall framing, ceiling framing, roof framing, roofing materials, exterior and interior finish materials, hardware, steel joist floor framing, steel stud framing, and steel ceiling joist and rafter framing.

Weight 2.4600
ISBN 0-9663338-0-2
Page Count 496
Author Robert W. Petri
Publisher R.W. Publishing
Dimensions 8-1/2 x 11

This unusually well-organized book shows the best and easiest way to estimate materials for room additions or residential structures. It gives estimating tables and procedures needed to make a fast, accurate, and complete material list of the structural members found in wood and steel-framed buildings.

This book is divided into 72 units, each of them covering a separate element in the estimating procedure. Covers estimating foundations, floor framing, wall framing, ceiling framing, roof framing, roofing materials, exterior and interior finish materials, hardware, steel joist floor framing, steel stud framing, and steel ceiling joist and rafter framing.

Write Your Own Review

You're reviewing: Construction Estimating

Table of Contents

List of Tables, xiii
Preface, xv

SECTION 1: INTRODUCTION, 1
1 The Estimator, 3
2 Building Plans, 11
3 Specifications, 26
4 Building Codes, 29
5 Abbreviations, 31
6 Estimating Forms, 34
7 Lumber Grading, 45
8 Estimating Lumber Costs, 48

SECTION II: FOUNDATIONS, 61
9 Concrete for Foundations, 63
10 Estimating Concrete Volume, 66
11 Estimating Foundation Bolts, 81
12 Problems-Concrete Volume, 84

SECTION III: CONVENTIONAL WOOD FLOOR FRAMING, 93
13 Estimating Mudsills, 95
14 Estimating Foundation Posts, 98
15 Estimating Concrete Pier Blocks, 101
16 Estimating Girders, 103
17 Estimating Floor Joists, 105
18 Estimating Header Joist, 110
19 Estimating Floor Bridging and Blocking, 113
20 Estimating Floor Sheathing, 119
21 Estimating Foundation Vents, 123
22 2-4-1 Floor Framing System, 125
23 Problems-Floor Framing Materials, 130

SECTION IV: WALL FRAMING, 133
24 Methods of Wall Framing, 135
25 Estimating Wall Plates, 141
26 Estimating Studs, 148
27 Estimating Gable Studs, 151
28 Estimating Headers and Beams, 153
29 Estimating Diagonal Wall Braces, 160
30 Estimating Wallblocking, 164
31 Estimating Wall Sheathing, 166
32 Estimating Temporary Wall Bracing Material, 173
33 Problems _ Estimating Wall Framing Material, 175

SECTION V: CEILING FRAMING, 183
34 Estimating Ceiling Joists, 185
35 Estimating Ceiling Backing, 189
36 Estimating Stay Lath, 191
37 Estimating Purlins, Ridge Props, and Collar Ties, 193
38 Estimating Dropped or Soffited Ceilings, 196

SECTION VI: ROOF FRAMING, 199
39 Types of Roofs, 201
40 Roof Members, 204
41 Roof Terminology, 207
42 Roof Framing Methods, 209
43 Methods of Estimating Common Rafter Material, 211
44 Estimating the Number of Common Rafters, 217
45 Estimating Common and Jack Rafter Material for a Hip Roof, 222
46 Estimating Hip and Valley Rafter lengths, 224
47 Estimating Ridge Board Material, 227
48 Estimating Fascia and Bargeboard Material, 232
49 Estimating Gable lookouts, 240
50 Problems - Estimating Roof Framing Material, 242
51 Types of Roof Sheathing Material, 248
52 Eave Details, 250
53 Estimating Starter Board, Solid, and Skip Sheathing, 253
54 Problems - Roof Sheathing and Starter Board Material, 265

SECTION VII: ROOFING MATERIALS, 273
55 Types of Roofing Materials, 275
56 Estimating Roofing Materials, 279
57 Problems-Roofing Material, 284

SECTION VIII: EXTERIOR FINISH MATERIAL, 289
58 Estimating Exterior Doors, 291
59 Estimating Exterior Door Frames, 295
60 Estimating Exterior Window Frames, 299
61 Flashing Paper, 302
62 Estimating Exterior Cornice Material, 304
63 Estimating Exterior Siding, 316

SECTION IX: INTERIOR FINISH MATERIAL, 333
64 Estimating Interior Doors, 335
65 Estimating Door Frames (Jambs), 340
66 Estimating Door Casings, 344
67 Estimating Doorstops, 347
68 Estimating Window Trim, 349
69 Estimating Closet Trim, 353
70 Estimating Baseboard and Base Shoe, 356
71 Estimating Interior Wall Paneling, 359

SECTION X: HARDWARE, 363
72 Hardware-General Information, 365
73 Framing Hardware, 366
74 Rough Hardware, 373
75 Finish Hardware, 376
76 Cabinet Hardware, 385
77 Miscellaneous Hardware, 389

SECTION XI: INTRODUCTION TO STEEL, 391
78 Light Gauge Steel Construction, 393
79 Steel Building Methods, 401
80 Advantages and Disadvantages of Steel Framing, 404

SECTION XII: STEEL JOIST FLOOR FRAMING, 409
81 Fastening Plate Tracks, 411
82 Estimating Steel Floor Joists, 414
83 Estimating Steel Joist Tracks, 419
84 Rim Track Clips, 420
85 Steel Floor Joist Block and Bridging, 423
86 Web Stiffeners, 425
87 Estimating Floor Sheathing Material, 428

SECTION XIII: STEEL STUD WALL FRAMING, 429
88 Estimating Steel Wall Plate Tracks, 431
89 Estimating Steel Wall Studs, 433
90 Slammer Studs, 434
91 Estimating Steel Wall Headers, 436
92 Steel Wall Backing, Blocking, Reinforcement., 440
93 Diagonal Braces, 444

SECTION XIV: STEEL CEILING JOIST AND RAFTER FRAMING, 447
94 Estimating Steel Ceiling joists, 449
95 Ceiling joist Clips, 451
96 Ceiling joist and Rafter Anchors, 452
97 Estimating Gable Stud Tracks, 454
98 Gable Studs, 455
99 Common Rafters, 457
100 Hip and Valley Rafters, 463
101 Ridge Board, 466
102 Steel Rafter Strap and Rafter Block, 470
103 Box Cornices, 471

Index, 475

INTRODUCTION

The estimator's job is to prepare estimates of building project costs. Its importance cannot be overemphasized because the success of a contracting business depends on the accuracy of these estimates. The estimator's success will be based on his previous experience in and knowledge of the construction industry. A contractor or estimator lacking this experience may over- or under-estimate his project costs. That, in either case, could be detrimental to the success of his company: if costs are too high, his jobs will be few and far between; if costs are too low, he will not be able to stay in business.


THE ESTIMATOR'S BACKGROUND

Many successful estimators in the field of residential construction come from the craftsmen's rank and file. They have usually
learned their own particular trade well and kept their eyes open to other trades around them. To become successful estimators they have had to acquire both experience and knowledge of the whole building industry.

Estimators working for large commercial firms may also have come from the craftsmen's ranks, but they usually have supplemented their knowledge and experience through formal education, perhaps only with a few night school courses, perhaps
with a two-year or four-year degree in business or construction technology.

Some estimators in specialized trades may have acquired their knowledge of construction in the office as estimator trainees. In such cases, they are trained to take off and estimate the particular material or equipment of a specific trade even though they have no construction experience.

Those trades that use area measure as a basis of estimating are usually the easiest and fastest to learn, such as insulating, drywalling, plastering, stuccoing, painting, and roofing. Trades with harder to learn estimating involve the listing of many parts, such as plumbing, heating, electrical, and framing. It must be kept in mind that all trades require the estimator to read and understand building plans to some extent.

WHAT THE ESTIMATOR MUST KNOW

1. He must have a thorough knowledge of the building trades. This includes the various trades themselves, types of construction, methods of construction, and trade terminology. Although an the areas mentioned above are important to the estimator, trade terminology will often be the key to his success. For if he is to communicate effectively with subcontractors and material dealers, he must possess the ability to speak their language.

2. He must be able to read building plans and notes and understand the specifications. By studying the plans and specifications, the estimator will get a general view of those things that pertain to his phase of the project. If he finds any discrepancies between
the plans and specifications, he will jot them down and bring them to the attention of the architect or owner for solution. When
an the questions are answered and problems solved, he can then prepare and finish the cost estimate.

3. He must have a thorough understanding of the building code and ordinances in the area the building project is to be constructed. The estimator should understand that even though adjoining cities use the same basic code, certain items win vary because of the interpretations of different building departments. For this reason when questions arise about building practices and
code requirements, the contractor-estimator should check with the local building department for the answers. Building officials and
inspectors are public servants and are there to answer your questions at any time.

4. He must have a thorough understanding of construction materials. A contractor estimator through experience will acquire the knowledge of a vast variety of construction materials. He must understand, therefore, the sizes, strengths, and capabilities of the materials with which he works. He must be able to intelligently substitute equal quality materials when specified materials are not available. By having a good working relationship with his material suppliers, he will know what materials are or are not available
in the local area of construction. And last, he must keep in touch with and understand present and future prices of building materials.

5. He must keep up with the new construction products and materials that are continually being developed. To keep current, the contractor-estimator should visit trade and home shows and subscribe to construction trade and building magazines. There are some excellent magazines available today, and the advertising in these will keep him aware of what is new on the market.

6. He has to possess some basic mathematical ability. The estimator doesn't have to be a genius in math, but he must possess the ability to work accurately with the four basic functions: addition, subtraction, multiplication, and division. Every estimator should have a good basic or trade math book available to handle any special math problems that may arise.

7. He has to have at his fingertips reference materials, books, tables, and tabulating equipment to speed his job. In time, he will acquire reference materials in the form of material catalogs, brochures, and manufacturer's specification sheets for the products he uses on many of his projects. He will acquire various reference books related to building and the construction industry. There are some excellent estimating, building material, and carpentry books on the market today that would add to and fill in the areas not covered in this book. And he will have to acquire time-saving estimating tables, usually printed tables from various sources, that may be used as is or modified for his personal needs. He may even choose to makeup his own tables and waste factors.

With the new inexpensive pocket and desk calculators available today the estimator can tabulate and check his estimate with a minimum of time and effort.

8. Finally, he must project labor cost changes. The estimator must realize that labor costs may vary in different geographical areas of the state or country. He must also realize and project in his estimates future increases in labor costs because of upcoming union contract negotiations, for instance.

THE ESTIMATOR'S DUTIES

1. Quantity Material Take-off. This is an itemized list of materials needed to build a project or phase of a project. The items are listed in the order in which they will be used in the construction of the building. In this book we will be concerned with the material take-off of concrete, rough framing lumber, interior finish lumber, and hardware. These are the categories, with the occasional exception of concrete, that are usually handled by the general contractor.

The other areas of a project are considered subcontracts; these would be subcontracted out to the specialty trades.

2. Labor Take-off. This concerns the number of man-hours or approximate hours and the cost for those hours for a particular
phase of work on a project. There are estimating books and materials available today on labor costs, but these should only be used for fast or approximate estimates; they take into account a work average and not the work efficiency of one crew of men over another. Many contractor-builders on small jobs break down the project into small units of work (man-hours). They do this by studying the building plans to answer the questions of how many hours it will take for demolition on this job, how many hours
to joist and cover the floor, how many hours to frame the walls, how many hours to add for any unforeseeable problems that may
arise, and so forth. This time is all then added up and multiplied by the going rate per hour for a total labor cost. This method requires a good deal of field and estimating experience.

An extension of the above method for breaking down labor costs is the unit-labor cost for piecework. In other words, one to
four-men specialized crews do various phases of rough framing or finishing work and get paid by the lineal foot or square foot of material applied or constructed -- 12� a lineal foot for wall framing, or 50� a square foot for exterior siding. This method makes it easy for the estimator to plug in labor figures and come up with a total labor cost. Piecework, fortunately, is not used very extensively throughout the country, for it does not produce a very high quality of workmanship.

Other estimators, using previous experience, set up labor costs based on square foot costs. They may have various costs for different types of construction which, when multiplied by the square footage of a project, determines the total labor cost.

Whichever method is used, it is important to keep in mind that the ability of the work crew, the workmanship required, the tools used, and the weather conditions all playa major part in the effective production of a skilled craftsman.

3. Subcontractor Bids. Those phases of work on a project that the contractor does not do with his own personnel have to be subcontracted. The estimator must acquire from the various subcontractors the cost estimate, known as the bid, for labor and/or
materials for their phase of work. Over the years a contractor-estimator will compile a list of reliable subcontractors. He should
have from three to six for each phase of work on a project. The estimator contacts these subs by phone or mail to let them
know there is work available to bid. Some subs will respond, though others may be too busy to take on any more work at that time. In any case, the estimator should acquire a minimum of three bids on all phases of work to keep the subcontractors competitive.

4. Compilation and Presentation of Total Bid Costs. The cost of material, labor, subcontracts, and the contractor's overhead profit have to be added together to determine the total cost of a project. This total bid is then submitted by the contractor to the owner for his approval.

ESTIMATOR'S DUTIES DURING CONSTRUCTION

1.
Organize Construction Time Schedules. The estimator may be called on to organize a tentative time schedule of events from the beginning to the end of each job. This schedule may involve ordering materials and lining up subcontractors to make
sure the job runs smoothly. As the job progresses from phase to phase, the estimator may also be called on to schedule the building inspections.

2. Check on Fluctuating Prices and Availability of Materials. Quite a bit of time may elapse between the contractor's being awarded a project and the start of that project. For this reason, the estimator may be called on periodically to check with
his material suppliers for price fluctuations and availability of certain materials. The estimator will also have to check on the time it will take to order and receive certain building products or specially milled materials.

3. Award Subcontracts. The estimator may be called on to contact and line up in his time schedule the subcontractors with the lowest bids. Some subs may be too busy to be scheduled for a certain time in the general contractor's time schedule. If this is the, case, the general contractor has the choice of holding up the job until the subcontractor can get there or calling the sub with the next lowest bid and scheduling him for the job. The general contractor's cost for doing this will be higher but may be offset by getting the job done on time.

4. Record Job Progress. The estimator, as previously mentioned, may set up a tentative time schedule before a project starts. This tentative schedule, after construction does start, will be checked by the estimator against the actual job progress. In an ideal situation the job runs smoothly, according to the tentative schedule. But unforeseeable problems may arise that will not allow the work to progress on schedule-problems such as late deliveries of material, subs not reporting on time, inclement weather, labor strikes, etc. A form like the one illustrated on p. 43 of Unit 6 will help the estimator understand where each of his jobs should be, and where the job actually is, so he can schedule the unfinished work accordingly.

5. Do an Analysis at Job Completion. It is advisable for the beginning or experienced estimator to analyze a few jobs now and then to come up with an accurate or sound basis for doing fast or preliminary estimates in the future. The analysis should also tell the contractor or estimator if he is within the profit margin set by the company. If a contractor did not make the percentage of profit he expected from a job, where did the excessive cost go? Was it in the labor, in the materials, or in an item that was forgotten in the final bid?

If a contractor made a higher percent of profit than expected (there really is no such thing as excessive profit in the opinion of contractors), the estimator should try to find out where it came from. Was it saved on labor? If so, at what stage of construction? Was it saved on material? If so, on what type of material? When the construction industry is booming, a contractor will usually bid his jobs higher. When the industry slows down, he will have to sharpen his pencil and become more competitive if he is to survive. In slow times the contractor who has analyzed his previous jobs carefully will be more competitive, thus keeping himself and his staff
in business.


STEPS IN ESTIMATING

1. Building Plans, Notes, and Specifications. The estimator must familiarize himself with the building plans and specifications. This may take a few minutes or many hours, depending on the estimator's past experience and the complexity of the project. He will take notes on items in question to be answered later by the architect or owner. After these questions are answered, he is ready to go on to the next step.

2. Material Take-off. The estimator must make an itemized list of the materials his company will be responsible for on a project. The items on this list, as mentioned before, are usually arranged in the order they are to be used in the construction of the building. After completing this itemized take-off, the estimator sends it to the material suppliers for a competitive cost breakdown.

3. Labor Take-off. The estimator's method of assessing labor costs will be used to determine the hours and cost for those hours of his phase of work on a building.
The various methods of labor take-off mentioned on pp. 5 and 6 all rely on the contractor-estimator's previous estimating and field experience. Without this previous experience, a beginning estimator will find it almost impossible to do an accurate labor take-off.

4. Subcontractor Bids. The estimator must make the building plans available to the subcontractor so he can take off the materials and labor for his phase of the
building. Ethically, the estimator should award the work to the subcontractor with the lowest bid, but this does not always hold true. Some contractors may favor certain subs even though their bid is not the lowest because they believe that good workmanship, dependability, and fast performance are worth the extra cost.

5. Equipment Rentals. Occasionally, certain equipment is needed on a job that is not worth the contractor's investment. This equipment, when needed, may be
rented from an equipment rental yard. The estimator must survey the job, decide what rental equipment will be needed, check on the costs of these items, and add them to his estimate. Items usually rented include fencing, power poles, power tools and equipment, machinery, toilet facilities, scaffolding, etc.

6. Complete Building Costs. The estimator must add up the building permit fees, material costs, labor costs, subcontract costs, equipment rental costs, and add to this his contingency, overhead, and profit figures. The contingency figure is an amount of money added to the bid for any unforeseeable or forgotten items. The contingency and profit can be lumped together because any money left in the contingency fund becomes profit.

Overhead refers to a contractor's operating costs. It includes such items as office rental and utilities, office equipment, salaries of office and management personnel, equipment (e.g., trucks, power and hand tools), and maintenance. These costs are continuous even though there are no projects presently scheduled. Therefore, overhead costs are spread over each of the contracted jobs.

A contractor often draws a salary for his time and effort on a job. The added responsibilities of supervision, plus the financial risk he assumes, also entitle him to a certain percent of profit. This percentage is usually based on the availability of work and on competition.


METHOD OF ESTIMATING

The size of a contractor's business and the use of the company personnel determine the estimator's method of estimating his jobs. For example, the contractor-estimator who estimates the materials for a job he is going to supervise or build will be able to order specific lengths of lumber for each phase of framing, and when he starts the job, he will know just where each length should be used. This builder may estimate his job with a minimum of waste.

On the other hand, the contractor who employs an estimator to estimate the material and who has a foreman or superintendent on the job must order enough material so that the foreman and crew do not run short. With a crew of men there is often indiscriminate cutting of certain lengths of material. The estimator must therefore increase his estimates to allow for waste material. It is less expensive for the contractor to have a few extra lengths of lumber at the end of a job, than to delay the job while obtaining the needed material.


PRELIMINARY OR FAST ESTIMATE


A preliminary or fast estimate is one in which the estimator doesn't have to go through the process of completing a material and labor take-off or compiling subcontractor bids to arrive at a cost for a project. He can devise a method of determining an approximate or actual accurate cost. This cost is usually based on an analysis of previous jobs and is often given as a square foot price for a certain type of construction, at so many dollars per square foot. The estimator must also take into account various framing methods and materials used when making up this square foot cost. Many architects also use a preliminary estimate in their first contact with clients. This estimate gives their clients a ballpark figure of what the project will cost.

GENERAL CONTRACTOR'S COMPLETE ESTIMATE

A general contractor's complete estimate includes the building permit fees, the material, the labor, and the machinery and equipment necessary to complete a project. If the general contractor employs an architect or home designer and provides the drawings, he will also include the cost of the building plans.


SUBCONTRACTOR'S ESTIMATE


Subcontractors hired by the general contractor usually furnish the materials, equipment, and labor necessary for their phase of work on a building project. Often, they take care of the costs of building permit fees as well. Occasionally, the general contractor, possibly because of his buying power, may want to furnish the materials and have the subcontractor simply bid on the labor. The subcontractor's bid, in this case, is known as a labor estimate. In such a situation the general contractor is responsible for the safety and security of the materials. In other instances, the general contractor may not want this responsibility and will ask the
subcontractor to provide the material and labor for the project. For example, a framing subcontractor will be asked to provide the framing lumber. In this case the framing subcontractor becomes responsible for the security of the materials. This may cost the general contractor more, but it relieves him of many headaches on large jobs.


THE OWNER-BUILDER


Sometimes to cut building costs, the owner may want to act as his own general contractor. When he does, he must secure the building permits himself and contract with various subcontractors for the different phases of work. Before assuming this responsibility, the owner ought to know something about construction. If he doesn't, he and his subcontractors may end up in many disputes before the job is finished. The owner should also keep in mind that the more competitive bids he gets for each phase of work, the lower his building costs may be. And he should make sure that his subcontractors are reliable and that they specify in a written contract the following:

1. What work will be done and when.
2. What work will not be done.
3. What materials will be furnished.

This book has been designed to help the student, tradesman, prospective builder, or contractor learn how to estimate materials for room additions or residential structures. Divided into fourteen sections, the book deals primarily with rules and estimating procedures needed to make a material list of various structural members found in wood and light gauge steel frame structures. The first section deals with the estimator and the knowledge he must possess to become successful in the construction business.

Numerous illustrations have been included to assist the student to understand the written text and to emphasize construction terminology, plan reading, basic code requirements, and good construction practices. And for the experienced tradesman, estimating rules, tables, and procedures are an excellent reference and will help speed up his material take-off of concrete, rough framing lumber, finish material, and hardware. Although every estimating situation the builder encounters cannot be handled in one book, the examples express a variety of situations which can help solve future estimating problems.