Carpentry in Commercial Construction Overview
Covers forming, framing, exteriors, interior finish, and cabinet installation in commercial buildings: how to design and build concrete forms, select lumber dimensions, what grades and species to use for a design load, how to select and install materials based on their fire rating or sound-transmission characteristics, and plan and organize a job efficiently.
by Bryon W. Maguire
Carpenters working on stores and offices need specialized skills and knowledge not required in residential construction. This manual explains how to handle carpentry that's unique to commercial projects.
Formwork for commercial jobs must be designed carefully because concrete surfaces are usually larger and the pressure of wet concrete much greater than on residences. Chapter 2 explains the principles of good form design and includes tables so you can provide enough wales, braces, ties and shores.
Framing on stores and small offices is usually designed to meet load criteria established by the engineer. That makes selection of the right lumber and fasteners very important. Chapter 3 outlines basic timber engineering principles and describes how to select the right lumber grade and species.
Chapter 4 explains how to handle roof framing on commercial buildings and emphasizes the work most common on commercial jobs: roof trusses, heavy sheathing and overhanging roof surfaces on storefronts.
Chapter 5 tells how to install the wood sheathing, siding, doors and windows commonly used on commercial buildings. Coverage tables are included to help you estimate quantities.
Every chapter begins with suggestions on how to plan and organize the work to improve production, and ends with a step-by-step guide to actually doing each task described. Over 160 tables, charts, drawings and pictures are included to help you understand everything that's explained.
About the Author:
Byron W. Maguire has 45 years' experience in and around the construction industry. He has done, taught and written about almost every phase of construction, including residential and commercial carpentry, masonry and management. He knows the problems you're likely to face in commercial carpentry, and how to avoid or minimize them through advance planning and careful work habits.
Carpentry in Commercial Construction
Introduction
Overview of Commercial Carpentry
Commercial
carpentry:
the skilled methods used by carpenters working on structures classified as
commercial and non-industrial; that is, townhouses, single-level office
buildings, and the like.
Coordinating:
the act or acts in commercial construction of harmonizing the efforts of
contractors, staff, sub- contractors, and workmen who erect structures.
Directing:
in commercial construction, all the supervisory work by the contractor who heads
the entire construction project.
Planning:
the accumulation and organization of all the production factors related to the
building of a commercial structure by various people with specialized skills.
Procuring:
the planned hiring of men and purchasing of materials necessary for a commercial
construction project.
Residential
carpentry: the skilled methods used by carpenters working on structures
classified as residential; that is, single, detached houses
Scaffolds:
the elevated platforms or planking that are used by workmen when their work area
is above or beyond normal human reach
Structure:
in this text, a townhouse, one-level office, store, or a restaurant building
made from specially selected materials
Time-Line
plan: a management display chart on which the various phases of construction
are plotted in relation to time and duration
Man
is born curious and to live with adventure. His inquisitiveness leads him in
search of both the unknown and the answers to his questions. A residential
carpenter knows that there is commercial carpentry. He only has to look around
to see it. But what does it hold that might provide challenge and lead him to
success or failure, or awaken him to new learning?
The
atmosphere is very different for the carpenter who works on commercial
construction as compared to one who works on residential carpentry. A
residential carpenter working on detached single houses often is involved in
every phase of the construction from laying the footing boards, through
shingling the roof, to completing the interior. Frequently be meets the new
owners of the structure and has the opportunity to work with them. From this
association he derives a genuine personal satisfaction for a job well done, even
though he may be better at some phases of the work than others.
If,
however, the carpenter is a member of a crew responsible for just one phase of
residential construction, he becomes very adept at that one phase of work. This
crew method is a mass production technique usually employed to build tracts of
houses efficiently. The techniques of commercial carpentry are used. One crew
does framing, another sheathing and door and window installations, another
cornice and siding installations, and still another the roofing. Finally, a
select crew completes the interior work. The carpenter in this latter type of
work environment cannot easily obtain the same degree of satisfaction that comes
from working on all phases of single-house construction. If he maintains or
increases his level of skill, however, his peers and supervisors will quickly
recognize that and will rely on his judgment and expertise. Usually be will then
be promoted to a higher level of responsibility.
The
work atmosphere in light commercial construction is somewhat like that of
residential construction at which the owner is sometimes present and the
architect frequently. The rapport that usually develops soon leads architect and
carpenter to respect each other's skills and talents.
But
the work atmosphere is also different. The carpenter on a commercial
construction job may move from one crew to another as the building takes shape.
He may build forms, then erect framing, and later do exterior and interior work.
These tasks often require both the carpenter and his supervisor to broaden their
skills. Let's begin to define the differences that the commercial carpenter will
find in his new environment.
INTRODUCTION
TO NEW WORK ENVIRONMENT
The
scope of commercial construction for the carpenter varies considerably-from
skyrise office buildings, through the shipbuilding and aircraft industries, to
townhouses, one-level office buildings, and stores. The environment you will
read about and study in this text and the principles you will apply are related
particularly to the construction of townhouses, small office buildings, and
stores.
From
these designations you can see already that there are two distinct types of
non-industrial commercial structures: office buildings and stores on the one
hand, and townhouse residences on the other hand. Each has task requirements
that differ significantly; however, there is also a significant overlap of
carpentry tasks which apply to both types of structures. The study of townhouse
construction provides a natural bridge of understanding from residential to
light commercial construction.
Let's
list simply but comprehensively the relationships and differences among the
types of construction. See Table 1-1 to start with the overall picture:
Beginning
with the next chapter each work activity in Table 1-1 is examined thoroughly and
logically chapter by chapter. The magnitude of the differences of work in
different environments is specially discussed. But, to understand the general
implications of the data in Table 1-1 consider these factors briefly.
Concrete
formwork is more extensive for townhouse construction than for detached houses
because of design differences and because of the size of the units and the
number of units being built. In addition, gardens, curbing, and sidewalks are
usually formed for townhouse developments as well as trash locations and so
forth. Often a swimming pool or two is built at the same time. But office
buildings require the most extensive concrete formwork. In fact, proportionately
there is more formwork than any other single activity done for office buildings.
In
residential construction, framing work consumes the majority of time on the job
(45%). It consists of making floors, walls, partitions, sheathing and doing the
numerous tasks associated with this work. Townhouses usually require slightly
more framing (50%), while office buildings usually have limited framing
requirements (10%).
Building
the roof of a structure usually requires considerable time and effort. As you
can see in Table 1-1, residential roofs account for a greater percentage of time
than do those on townhouses and office buildings. Even through more and more
truss roofing is now used in residential construction, a greater proportion
continues to be "stick built." The truss roof, however, is employed
for most townhouse and office building construction.
Exterior
carpentry activities are often difficult to predict completely because a variety
of exterior materials, such as stone or brick, are not applied by carpenters.
But certain man-made products do require the same work skills as lumber products
and are sometimes used on townhouses and office building exteriors as well as on
residential exteriors.
Interior
work includes installing partitions, wall paneling, trim, doors and ceilings.
Generally these activities are the same for both residential and townhouse
construction. A larger percentage of the carpenter's activities may be spent in
office construction, however, because of the extensive use of prefinished
materials.
Finally,
there is more cabinet work for the average single residence than for the
townhouse and still more for office buildings be- cause requirements for custom
cabinets are frequent. Almost all cabinetmaking in townhouses simply consists of
installing pre-built kitchens and bathroom vanities.
We
have noted the overall differences and similarities of residential and
commercial work activities. it follows that there must also be a different
approach to managing a commercial construction project. Whether you are a
contractor, a subcontractor, a foreman, or a journeyman your responsibilities to
or for management will be significantly different. Even if you are now only a
trainee it is essential, nevertheless, that you know and understand some of the
management problems so that you will be able to support your bass better. Table
1-2 presents some areas of management concern and their relative importance in
each work environment by showing the distribution of responsibility.
Looking
over Table 1-2 will help you appreciate that contractors often use the skills of
specialists on commercial jobs. The management work frequently subdivided,
includes materiel procurement, training, and, often, the scheduling.
Let's
examine each activity briefly. Planning means developing a schedule of action so
a job progresses in right order. Having men and material available at precisely
the right moment is, of course, the ultimate objective of all job plans. This
may be a complex task, especially if activities are interrelated or if other
contractors are involved. A good plan accounts for the major operations and
takes into account the possible circumstances that could alter them. A Time-Line
plan like that in Figure 1-1 visualizes all phases of the work and the amount of
time allowed for each at various stages in the schedule.
Coordinating
is the harmonious arranging of activity-between contractor and foreman,
between contractor and architect, between one contractor and other contractors,
and between foreman and architect. Coordinating also involves liaison or lateral
trust and reliance on a man to man basis and on a crew to crew basis. In
addition, coordinating means ensuring that materials are supplied on time to the
job, and inspecting each phase of the work. Coordination also ensures that all
people on the job remain in contact and are mutually advised and informed of
either availability or delays so that work proceeds oil schedule.
Training
is a two-fold organizational activity. First, someone in management defines
skills requirements and then translates them into skills on hand, skills needed,
and skills to be trained for. Secondly, the same manager (or his designated
develops a training plan that assures that the skills of the appropriate workmen
are available when needed. As shown in Figure 1-2, a single form can record both
the needed job skills and the qualifications and limitations of available
personnel.
Procuring
is the obtaining of materials and men needed for each work phase. it is
particularly important for successful management. Since the various job
deadlines are critical to construction schedules, a great deal hinges on good
procurement methods. The materials, machinery, and supplies necessary for job
completion must be ordered so that deliveries either precede or coincide with
on-site usage. Work-men must be hired and/or trained according to job
requirements, and, if specialized skills are needed, those responsible for
procuring them must calculate sufficient lead time. This essential phase of
procurement is usually interfaced with the training plan.
Directing
in the commercial construction environment is also a two-fold activity. At
the top management level the contractor directs the whole job, seeming sometimes
much like an eight-armed octopus. Each organizational activity is also assigned
a director. Sometimes, of course, the man in charge may wear more than one hat
and function as director of several activities. Those who receive the closest
direction are the crew members. They may not require individual direction on
every task performance but they often are given new orders weekly, daily, and
sometimes hourly.
From
this somewhat lengthy introduction, you can begin to under- stand some of the
differences between residential carpentry and commercial carpentry. But before
you proceed with discussions of task and organizational activities, it is
important to recognize that safety requirements are rules provided for your use
and well-being.
SAFETY RULES
Safety
on the job is very important. National agencies like the Department of labor and
the FHA concern themselves with the welfare of the worker on the job. Insurance
companies are also concerned. Your own acceptance and implementation of safety
practices will usually guarantee you a safe working environment.
Many
factors must be included in any safety program. If they are carefully integrated
in production plans several objectives can be accomplished in one operation. The
following safety measures illustrate this point:
-
Plan for adequate storage of new, used, or reclaimed materials by selecting an
area that ensures a clean working site. For example, as forms are stripped
from walls and footings, they must be cleaned and then stacked out of the way
until needed again. Consider-if a man has already lifted the board, how much
more trouble is it to walk 30 feet with it and stack it out of his way?
-
Level and compact the ground during all excavation work. Grading and firming
for a few minutes with the right machine can eliminate, even if only
temporarily, any obstruction that might impede workmen. It will also provide a
safe surface on which to build forms or erect scaffolds.
-
Build scaffolds properly and brace them with first-quality materials. Many men
will walk, work, and stack materials on scaffolds so the proper reinforcement
of supports, walking planks, and back rests is essential to good scaffolding.
-
Specify work clothes that promote personal safety: hard hats, steel-toed shoes
with tie laces, shirts without trailing sleeves, etc. Remember, proper
clothing contributes to job safety. Loose shoes and clothing are frequently
the cause of on-site accidents; and the unfortunate thing is that most such
accidents could have been avoided.
Safety
of personnel cannot be overemphasized. Consider that a given work force is
limited. If only the minimum of essential skills and experience are available
for the job, the temporary loss of even one man through a serious accident may
result in total loss of profit on the job and, even worse, in a personal loss to
the workman and his family.
You
will find out bow important safety precautions and general preparedness are for
qualified workmen engaged in commercial carpentry as you study the techniques of
commercial formwork in the next chapter.
REVIEW QUESTIONS
-
Define two aspects of commercial carpentry that differ from residential carpentry.
-
It is customary to find crews of carpenters specializing in separate phases of commercial carpentry. True or False?
-
What is a reason for the greater amount of concrete formwork done for office buildings?
-
Name the five major elements of an organization.
-
Explain the importance of coordination in a commercial construction job.
-
Who does the procuring for the organization and what are some of his responsibilities?
-
List four major areas of a job in which safety plays an important part.
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