Cadtales

Redlining

by Jim Rogers,
CADreps

Google redlining and you will get a plethora of books, articles and treaties on restrictive lending and insurance practices. Red-line is also used to designate a safety limit on an instrument, draw a canceling line through an item, and to mark for editing, deletion or correction. It is this last definition and use that finds application in engineering and building departments to amend and highlight items on a drawing to be changed by the designer or drafter. At CADreps we work with dozens of companies and hundreds of “after-the-fact” drawings, or more commonly known as as-built, or record, drawings. These originate as published prints used in the construction of buildings, installation of wiring & equipment, and are generally marked-up to show the actual construction.

In this issue we’ll define the term “redline” as it pertains to editing engineering drawings, formalize and document the redlining process and, hopefully, bring a little sanity to a field of activity that, for the most part, has all the discipline of a spoiled child.

While you are at the Google prompt, google “edit marks” or go directly to http://www.merriam-webster.com/mw/table/proofrea.htm for a list of editor’s and proofreader’s marks. We’ll use a few of these for marking text and linework for edit.

Definition:
red-line verb redline, –lined, -lin-ing,
-verb (used with a drawing or print object)

1. to treat by marking an area or object.

2. to mark with a contrasting color.

3. to mark for edit, revision, correction or deletion.

4. to set apart (as in explanatory notes not otherwise part of the drawing).
   -verb (used without a drawing or print object)

5. to engage in redlining.

-noun
6. Engineering.

1. a drawing, print, document or electronic file that has been marked for editing. (A redline).
   Synonym: markup

In actual practice marking pens, pencils, and highlighters of many colors are used to markup paper prints and CAD files for editing. Autodesk’s Design Review and Adobe’s PDF writer also use colors other than red for their edit marks and notes. Therefore, it will be more appropriate for us to use the non-hyphenated version of redline to describe our engineering markup work.

Too many as-builts are an afterthought at the end of a contract when the builder or installer learns that final payments will not be made until proper as-built drawings are submitted and approved. PANIC! Everyone rushes around searching for CAD files, finding the foreman or installer to do the markups – and then expects overnight service from CADreps (which we are happy to provide). Think about the need for markups at the beginning of every job and contract. Does the contract require as-built drawings in both paper and electronic (CAD) formats? AutoCAD, PDF or other formats?

Construction prints and CAD files are usually included with contract documents. These CAD files may not be appropriate, however, for creating final as-builts. In many cases the contractual work will be done with paper prints and, consequently, not realize that background CAD files are required as the basis for as-built CAD files. Are CAD files available? If not, paper prints may have to be scanned and traced to provide the necessary electronic file format. (For reference go to www.hagerman.com and see the “Cadtales” archives for Productivity – Personal Skills, Etransmit – The File Transmittal Utility and other articles on managing CAD file quality and integrity).

Process:

As noted in the Productivity Cadtales article referenced above: There is an important distinction between being efficient (doing the same work more quickly) and being more effective – designing a process that:

1. Insures quality

2. Insures on-time delivery

3. Eliminates rework

4. Insures you’re always under budget

5. Delivers greater than average profits

Here is a check list to use in the planning process to provide timely, accurate and legible redlines:

1. Request background files for creating working drawings at the beginning of every job and contract. This provides ample time to scan and trace paper drawings (when necessary), to cleanup and print paper copies for field reference and, give operators a place to record building and installation notes and variances. (Background files are base (or external reference) files for the site, building outline, etc. Background files for an electrical or communication wiring project would cover the floor plan, windows, walls and doors, and furniture & equipment when applicable).

2. Drawings change! Especially during the construction phase. Check for and use the appropriate drawing revision level for the markup print. The same
   goes for CAD files – the CAD file should match the version level of the markup sheet(s).

3. Use contrasting colors to mark changes. Pencils, pens and highlighters come in an endless variety of colors. Choose a color scheme and be consistent. (I prefer Paper Mate Flair felt tip pens in red, but available in fourteen other colors). If you make and use B&W copies of work and markup prints note that some combinations of pen colors and highlighter inks are incompatible. Liquid highlighter pens may smear Xerographic inks (toners) more easily than ink jet inks. Xerox copies of some highlighter colors may appear nearly opaque and lead pencil may be nearly unreadable. Test your highlighter and pen/pencil colors together and make copies to test for visibility and transparency.

4. Use full size sheets. Smaller size prints are handy for reference, portability and archiving but lack the readability and space to be used for redlining. (I keep a 5” magnifying glass handy – just in case).

5. Use the available white space. Use leaders to point to symbols and features buried among other linework and text. Print large and legible! Use a sharp pen or pencil. Leave room to line-out (mark for edit) and replace or correct.

6. Do NOT use whiteout. Whiteout is made to be invisible on white paper – and invisible is not good when an engineer or drafter is expected to make the CAD file reflect the changes on the paper markup. Try the marks in the example below to highlight items for change or deletion. Group items with a cloud – then mark for edit or deletion.

7. Edit marks should be discrete and un-ambiguous. Designers will often verify quantities by marking their first count with a slash “/”, followed by a second count using a back-slash “\”, most times in a contrasting color. Put these two marks together on a B&W copy and you have an “X” – a mark most often used to indicate a deletion!

Many of the above suggestions may seem obvious but take it from a 12-year veteran, “They are certainly not obvious to many operators creating redlines or markup drawings in the field.” Establish guidelines for your company and train operators to plan for and prepare proper redlines and as-built drawings. A typical redlining example appears below.

Do you see a productivity and quality benefit in improving the redline process in your design and drafting environment? Call your Hagerman & Company sales representative about software upgrades, training and customization.