Surveyor's Footsteps: Be Careful When Making Your Mark
With a few years of stakeout experience, most surveyors have been asked many times to “set a benchmark.” That could be one of the most risky acts for a party chief.
So, why would a contractor ask you to make your mark? The answer is simple. If things are wrong because of survey errors, you or your boss can be held accountable and possibly sued.
We may then look at the base topo, find a few manhole rims, take shots, get an average and set the site benchmark. Even if a site benchmark is shown on the plan you are given, I suggest you check it against other features shown, like doorsills, inlet tops and pipe inverts.
Compared to the ramifications caused by an incorrect benchmark, our hourly rates are nothing. The builders of high-priced homes and commercial sites often work at a “cost plus” fee. If they pay $100 an hour for a survey crew, they will charge an additional 15 percent. They make money hiring your crew. So, if you take longer to check your work, they will earn more for doing nothing but charging their client. Don’t feel bad if you spend time to make sure you are correct.
The best benchmark when an addition is being put onto an existing commercial building or house is the floor they must meet. Contractors want you to put a nail in a tree somewhere, or a mark on a wall which they feel is easier to work from. I understand their reluctance to transfer a grade, and again they pass on the cost of your crew, but I would encourage you to not set the “extra” benchmark and push them to use the monument they already have — that being a structure they must match.
I recall a builder asking me to set a benchmark at the new finished floor of a building he was constructing. This building was to be connected by a long breezeway, which had to meet an existing second floor elevation. I was immediately uneasy with the request.
I was emphatic that I did not know anything about the relationship of the building to the new building or how far it was from the proposed first floor to the proposed second floor. The simple math is that if you have the existing second floor and measure down X.XX feet (as given by the architect), you will have your new building’s first floor.
So, the builder called the architect on a Saturday and got a number over the phone, and I took a location of what the builder told me would be the finish grade on the existing second floor. You see, that was also a recent addition still under construction and met the existing second floor of the mansion … and the floor was not exactly there. Since I knew the proposed existing finish floor (yes, that’s what it still was, proposed), we subtracted the distance provided. On one of my existing hubs, I marked the new first floor elevation of the new building. The builder was right there and the lath was clearly marked.
Next, the subcontractor took the architect’s plans with a proposed elevation that did not take into account the real elevation of the existing second floor. There was a difference of about five inches. When I was called back out due to elevations issues, the builder was called on the phone and I overheard him complaining about the layout — my layout. I kept quiet to see how the hand would play. Working in the capacity of a party chief, it’s best to not make any admissions unless you know for a fact that you are wrong, and then not until you have reviewed the facts with your employer.
I managed to explain to the subcontractor that the proposed finish floor on the foundation plan was assumed. The problem here was it was close to a real elevation. Had it been 10 feet or 100 feet different, they would have called me earlier and I could have pointed out the stake I set with the real elevation of the new building’s first floor. I try not to get involved with intense large commercial layout jobs. I believe the carpenters union here in the Philadelphia area is very good at that sort of work.
I was blessed at this site to encourage the subcontractor to ask the architect for the dimension between the now existing new second floor and the proposed first floor of the new building. With a box tape, they measured vertically and made a mark on the doorsill of the first floor below.
I want to mention that the breezeway was only between the second floors, and there was a sidewalk from the new existing first floor of the recent addition and the proposed first floor of the proposed building. I apologize if this explanation is not clear, but it was not clear when I was on site. I liked the new benchmark because it had no risk for me and would definitely work.
Mistakes Still Do Occur
This whole uncomfortable process made the builder upset. I took measurements of the hub I set with him, photos of the lath and what was marked on the lath, and then took a reading on my back sight in case anything further came up about the elevations.
Working through the new elevation for the proposed first floor marked on my lath, it was one-tenth off — much closer than the five inches once believed. The builder never explained to the subcontractor that he should have been working to the new elevation instead of the number on the architect’s plan. I did have site elevations for my hubs, but they were used for civil design work and I have no idea where that existing second floor elevation used to create the bogus design elevation came from. But I would guess the architect arrived at that incorrect number.
I did point out to the subcontractor my lath with the real elevation of the proposed first floor. By then, he did not care and was plowing forward.
When my party chief returned to reset some of my control hubs, he met the person they would have on site to do the remaining layout. Was I disappointed? No. My party chief, knowing little about the past difficulties of the job told me, “That guy they got to do the layout does not know what he is doing. He asked me a lot of dumb questions.” Good luck with that.
Having set control points for some quality carpenters, I appreciate when a person knows his or her job. It comforts me knowing my work will be followed by professionals.
One of the best construction layout surveyors I have known made an error setting a mark for a finish floor of a building the size of a large Sears store. An extra foot of material was dug out of the basement. What happened? Our employer bought a foot of stone. It happens; mistakes are made, even by the best. My Missouri boss told me, “If a man says he never made a mistake, he must not be working.” Saying this, he was preparing me for a day when I would be sweating it.
When things go wrong and mistakes are made, the plan of action should be to keep quiet and listen to allow builders and subcontractors the time to think of how they can fix a problem. Good people will not look to blame anyone, and most builders are good people. They want to keep the job moving. Some will initially jump to find people to blame, but when they cool off they often become problem-solvers.
Make Friends, Not Enemies
Nearby is a major hospital where the new high-rise addition floor elevations were different from the existing high-rise building … by several inches! Unexpected slight ramps in floors can be trip hazards. I have no idea how it happened or who it may have cost. When I heard the story, I was glad not to have been involved.
Over time, we hear these survey nightmares and I believe it’s good to repeat them to our staff as lessons. Routinely, my old employer had his attorney come and give talks to the company staff about various liability issues. The cost of these seminars was a good investment in his business.
When I am setting controls for large commercial buildings and know they will be used by construction layout personnel, I like to talk with them and express how I respect their part of the work. I believe this builds trust and comradery between us. Should things look odd, they will call me and discuss it without feeling a need to pump their pride up. If you spend time with good layout people, it will teach you a whole different side of land surveying. They have tricks and understand more than can easily be put in a textbook.
I do not seek out construction layout work; it is risky and errors can be costly. When the surveys I perform later include layout work, I will follow the work to keep clients happy.
Recently, I was asked by a client to stake out from a plan prepared by a design company whose work I often question. I respectfully declined the work. The client sounded very let down, and expressed that he was counting on me doing the layout and that it was simple work. I encouraged him to pressure that company to back up its design work by doing the stakeout. I don’t want to take up some other surveyor’s backlog of work and the liabilities that come with it.
On a site long ago, the builder complained there was too much fill. He had the design engineer come on site to “adjust” the benchmark to lower the whole project by a foot. As a party chief, this really made me nervous, but the engineer was there and I was working at his direction. I set a nail in a tree at a given elevation. Then, we measured down a foot and set another nail, and called it the same elevation. Then I pulled the upper nail out of the tree. It was a large site and, any time I worked around the perimeter of the development and along the existing roads, I had to account for the foot difference. All went well, but I sure did a lot of checking throughout the entire life of the project.
My intent in writing this is to encourage us all to avoid setting unnecessary controls which might come back to bite us. In doing so, we are implementing that necessary and important life rule expressed as “CYA.”