Surveyor's Footsteps: An Old Adage Still Has Meaning
A potential source of good employees may be your local Vo-Tech school. Mine had an AutoCAD class taught over two years. A very good person I hired from our local Vo-Tech understood what “square with the world” meant. His understanding of how the real world worked included that generally there be 90-degree corners on houses, walks, porches, etc. I was amazed that a young man of 17 already knew so much.
Typical of my approach, everyone is encouraged and expected to learn to perform field work, and come in and draft the day’s work. With two people on a crew, they might do two or three jobs, and the first rain day would be sitting at computers and drafting their line work. Later, they would learn to contour, hatch, read subdivision plans for easements and setbacks, and enter deeds. To begin, they would simply connect the dots and turn Cartesian coordinates into line work.
I can’t remember the first time I heard the expression, but I do remember staking out homes and then our party chief would say, “Now let’s check the diagonals.” That was before hand calculators and, after the first house stakeout, anyone with an average intelligence knew that the two diagonal measures on a rectangle ought to be the same distance.
A few days ago, I staked out a garage. It was 16 by 22 feet and the contractor was concerned about the garage meeting the setback minimum. The offsets for stakes that fit the field conditions were 8 feet and were set off the right and the left sides. I did not check the diagonals as I was working by myself with the robot and, besides, my plumb bob was out on my deck where I am building a trellis. So, how did I check the diagonals? Before leaving the site, the three hubs and one nail I set were located and a check shot was taken on the garage floor for elevation, as well as a few house locations of the existing structure. Back at the office, I entered the coordinates for the new field shots and verified in the computer that the offsets were as they should be, and the existing structure matched my fresh locations.
One way or another, we all need to check the diagonals.
What really brings this to mind and why I wanted to write about this particular stakeout is the CAD drawing I was working with, which had been supplied by the engineer who prepared the permit plan. As usual, I check to see that the proposed building matched the architect’s foundation plan dimensionally. In this case, there did not seem to be a foundation plan, but in the email trails I easily found the architect’s direction to make the garage 16 feet by 22 feet.
Before continuing, I want to back up and mention that I looked at the plan and something did not appear correct. The proposed garage was not parallel to the existing house, or to the lot lines. The side lot line and rear line were 90 degrees or you might use the expression “square.” Using the inverse command, I checked and the garage was not quite a rectangle, having several seconds of angle error. Now this seems “nitpicky,” but when we are not “nitpicky,” we can end up with fleas. It is a necessary practice to assume that a building provided is incorrect and we surveyors, before performing a stakeout, need to verify that the proposed building is square, unless there are 30-, 45- and 60-degree changes in the direction of the foundation wall.
I brought the odd placement to the attention of the engineer, who referred my comment to the architect, who in turn said, “Do it just as it was permitted.” Remember, it was permitted as a paper drawing. Had I rotated the garage slightly to make it square with the property lines, the rear of the 22-foot deep garage would only have moved 0.29 feet, which in this case was nothing. Regretfully, I left it as the CAD drawing showed it to be. However, the plan called for the garage to be a minimum of 5 feet off the rear property line and the CAD drawing had it there, too.
Years ago, my bosses would see such layouts and move the house a foot back of the setback line if there was room. They did not discuss it with anyone in the office or the architect. The last thing they wanted to have happen is for a foundation to be put in over the line. I moved the garage 0.15 feet off the setback line in the CAD and staked it out that way in the field. Architects design foundations and engineers put them on plans right on the setback line because it requires only the snap to a line and they make it so. This does not account for the inch-and-a-half of siding which may be put onto the side of a garage. Some builders use stone facing or Styrofoam with stucco and could end up encroaching. Without a full set of architectural plans, I didn’t know any more about the garage except it was 16 by 22.
I did redraft the garage to make it a rectangle. Too often I am given a drawing to work from and the proposed drafting in the CAD drawing does not match the foundation plan, or is not square, or does not close. If you are working on a large commercial building, a half-inch is a large amount, and you will be working with prefabricated steel. The suppliers will have read the drawings and matched the proper dimensions. If they start burning holes in the steel in an attempt to fit the bolts, the focus will turn to the persons who laid out the building. Most engineers have disclaimers to protect them from dimensional errors and only guarantee the paper product. When you take a CAD drawing, consider that you are responsible for its use and checking it for accuracy.
In the past, field surveyors were brought into the office and already knew about being square with the world and not building right on a setback line unless there was no other way. So, if you are a graduate land surveyor and don’t have the field experience, please think about how to design features so there is less chance for an error to creep in; leave extra room if you have it. Will moving the building back an extra half-foot make a real difference?
This concept of design caution goes for grades on pipes and roads as well. If the minimum drop for a sanitary line is 1.0 percent and you can make it 1.5, why not? That difference will be an extra half-foot drop over 100 feet and may not make any difference. On a half-mile sanitary stakeout with a 0.5-percent drop with some of the line depths greater than 25 feet, I was extra careful with the cuts and elevations. Talking with the contractor about the flat grade, he said, “Oh, I’m not building it that way. It’s designed too flat. I raised it to one percent.” It worked out fine, but I was worried since he was pulling that extra 0.5 percent over a half-mile. It adds up.
Thankfully, he was installing it from the low end and proceeding uphill.
While I am on the subject, before feeling complete in your stakeout, check the grades on the plan. You could say it’s not your responsibility, but if you find problems and bring them to the attention of the designers, they will appreciate your quiet help and remember you. Another good expression? “What goes around comes around.” You may be the last professional to find errors before they are catastrophic. I can remember an employer being sued for using the minimum one percent on a road. Unfortunately, I don’t know how he made out with the lawsuit from the resulting hydroplaning car accident. That was before our 12-year limit on liabilities.
In Southeastern Pennsylvania, the Department of Transportation requires pipes to be a minimum of 18 inches in diameter. I’m happy with that, since it protects me from the temptation to use smaller pipe should the project only calculate to need a 12-inch pipe. When an 8-inch pipe can carry the flow, I go larger since I’ve see so many clogged 8-inch pipes in my area. In my judgment, using a larger pipe is in my client’s best interest. In our practice, we all develop our opinions of what is practical and prudent.
On a commercial site layout in nearby West Chester, I was putting grades on the offset stakes for the proposed curbs. Thinking about the site as a whole, I did some mental checking and felt a problem existed where they were building the new parking lot next to the building they were remodeling. Long story short, the parking lot would have been higher than the outside wooden wall of the house. The architect made a mistake in not taking into consideration the elevations of the structure and solved the problem by using steel plate to bridge the distance from the top of the foundation wall to the first floor. He appreciated my bringing the design flaw to his attention. The sooner you bring a problem to light, the cheaper it will probably be to make corrections.
My suggestion to any crew chief preparing to stake out a building would be to take the foundation plan and actually enter the dimensions in your own CAD layer and make sure the figure closes. Ask the architect for the most recent foundation plan; it can change quickly. Move your figure onto the one given to you in the CAD drawing and see if they match. You will be surprised how often they do not. As an experienced land surveyor or party chief, you offer a tremendous value to your client when you consider everything you stake out, and ask yourself, “Is this square with the world?”