Cover Story
Anatomy of A Plumbing Project — Part 2
by Alexander Schwarz
December 1, 2008
Every plumbing project is somewhat akin to a human body. Trying to cut off an “unimportant” part will cause the body to suffer — or even die.
In Part I of this article, I addressed three critical topics: infrastructure questions, service, and fixtures and equipment. Now it’s time to run to the drafting table and figure out what you need for…
Mechanical Spaces
Mechanical spaces are required for each and
every project. That is a fact of life.
It is absolutely necessary task for an engineer to do his “homework.” Guesswork
may be unavoidable at the beginning of a project and it serves the purpose well
if the guess is an educated one. However, before we can really commit ourselves
to anything, quite a few decisions have to be made.
- First things first, do your code search now.
Is a backflow preventer on water service required for the facility? It requires floor space, heat and drainage.
Is a backflow preventer on fire service required for the facility? It requires even more floor space, heat and drainage.
Is a fire pump required? Now we need space for a pump, a fuel source and maybe a transfer switch.
Next, try to make all your fundamental equipment decisions.
Is water pressure sufficient? Booster pumps take space.
What type of water heater should be used? Tanks take space.
Is an air compressor required?
Is an ejector required?
The process of allocating spaces is the next step after equipment selection — maybe even a parallel process.
Now we are ready to lay out our spaces. As a first step it may be advisable to create a block of space for each piece of equipment. Remember to add service spaces around each actual piece.
The second step is easy — find an appropriate spot for each block, considering noise, heat output, ventilation requirements, power requirements, drainage, water and fuel.
Are you all done? Confident in your layout? Sure you didn’t forget to coordinate your spaces with other trades?
If so, call the architect and tell him that you are ready for a meeting. As soon as your mechanical spaces are located, you will be ready for actual production, for the “bullwork,” for the next task…
Piping Layout
This process involves more patience than
creativity. Yes, there are multiple layouts we can come up with. But is it
practical to produce several versions? All of them will work. All of them will
be similar. And all of them will serve the same purpose. It is almost
impossible to save piping when you have to run it from point A to point B. A
straight line is the shortest anyway.
So where to start? Why not from the beginning? Mains should go ahead of risers,
risers ahead of branches, loops ahead of take-offs. Remember the remote units,
lonely fixtures and other guys’ equipment. When an HVAC unit isn’t shown on the
plumbing drawing there is a good chance it will be forgotten in the field.
After all, it takes a dozen steps in the office to get together with other
trades for the coordination. It may require much more effort in the
field.
Okay, the layout is done. Now is the time for sizing. Once again, start from
the mains. Count your fixture units, measure your roof areas, total your flows
and make sure that the system is functional. It might make sense to tag each
and every branch. Yes, your drawing will look busy. So you, too, will be busy
doing this work. A reference to the plumbing fixture schedule for a typical
branch pipe size to each fixture is quite sufficient and isn’t time consuming
at all.
Take a look at your drawing now. All major pieces of equipment are located, and
all your piping is laid out and sized. What’s missing? The design needs
“fine-tuning.”
Labels and Notes
To avoid any confusion, each plumbing fixture
must be marked with a label (usually a letter or a combination of a letter and
a number). Sinks and lavatories could be easily mixed up, as well as showers
and mop receptors. There are endless possibilities to become confused.
How important are fixture labels? They are your only key to identifying a
fixture on the drawing and to refering to the fixture schedule.
Without a label, all you see is just a square. Type “A” fixture may be a
regular water closet. Type “A1” will change it to handicapped. Type “A2” may
add an entire new feature, like a bedpan rinser. Make them “jump” from a
drawing. Make them large enough to see and clear enough to
understand.
Notes will add the final touch to the design. Notes must be as meaningful as
possible, and as much to the point as possible. Should we really say something
like “coordinate with all other trades, building construction, local conditions,
etc.?” What does it say? It sounds like “do your job.” How about saying, “run
pipe high between steel?” This is loud and clear. This is THE
NOTE.
Notes shouldn’t be repetitious. Almost any note that has to appear more than
once or twice can be converted into a general note. The sole purpose of a note
is to attract attention to a detail, to explain something that was not drawn.
Be careful with notes. Read them after you write them to avoid “clarifications”
that don’t clarify. And no matter what you are trying to say, do not misspell.
Finally, the floor plans are complete and ready for coordination and quality
control.
Now is the time to move to…
Schedules and Details
They are residing close to each other somewhere
at the end of a set of drawings or even on the same drawing. Are they equally
important?
The lion’s share of a project cost is in the fixtures. One error in a schedule
translates into as many errors in the field as fixtures of this type exist.
Where are these little annoying errors coming from? One source is copying from
another job, which may drag outdated numbers or discontinued items into
yours.
Another common source is combining a fixture description with a trim taken from
a similar fixture. How about those 25-digit long numbers? Try to copy all of
them without a mistake.
A good fixture description is not necessarily a very long and detailed one.
Clearly list all required options without describing every nut and bolt. After
all, you will have another chance to make sure that “it’s in there” during the
review of shop drawings.
Paying attention to details doesn’t mean we need more of
them.
Now, step back. Check your graphics. Read your notes. Just imagine for a moment
being a contractor. Do you have any questions? If your answer is yes, the time
may be right to come up with some details.
Try to avoid drawing pretty pictures. Time is money! Our world moves faster and
faster these days, and we simply can’t afford to spend our time on them. The
question becomes: What do we need to show to make a detail suitable for the
Information Age in which we live?
The sole purpose of a detail is to convey information. Your detail is your
helper and tool, not a proof of your drafting skills. Here are a few simple
rules to follow:
Well, it looks like the last drawing of the project is complete. Stop for a moment before moving to the next task. There are hundreds of specialties in plumbing. Some of them may be really unique and rare. Flip through the set one more time to refresh your memory, because it’s time to move to the final task.
Writing Specifications
Specifications are easy to write. All you have
to do is delete from the master specification all the things you do not need.
The trick is to eliminate any materials, methods or products that are not
desired.
The first step should be format selection. If a client did not ask for a
specific type of specifications, look
at the project size and complexity. For a small office renovation, a short form
may be suitable. However, for a major project, full CSI (Construction
Specification Institute) format appears to be appropriate.
Here are some tips to make spec writing a little easier:
Does it sound easy enough? Good! Because it is.
Writing a good specification requires patience and attention to detail much more than creative thinking.
Looks like our project is well wrapped up. Time to say good-bye. But before that, let me offer some words of wisdom…
Closing Words of Wisdom
(aka Common Sense)
Plumbing Project Checklist
Infrastructure
Questions
Services
Fixtures & Equipment
Mechanical Spaces
Piping Layout
Labels and Notes
Schedules and Details
Writing Specifications
Alexander Schwarz
Alexander Schwarz, CPD, was plumbing/fire protection department head for
Building Engineering Resources Inc. before his death. Established in 1994, BER
offers mechanical, electrical, plumbing, and fire protection engineering
services to the building design and construction industry. The firm can be reached by phone at
508-230-0260 or online at www.ber-engineering.com.
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