I finally found that elusive iron that marks a corner of our lot. And, just as survey experts warn, the official iron rod wasn’t exactly where the unofficial wood stake showed it was going to be. Lesson learned.

If you’re planning work around your house that might encroach on a lot line or setback, don’t learn the same lesson the hard way.

I wrote about my plan to find the corner iron last summer.

I didn’t get around to it in July of last year because, well, it was too hot. I put it off for a year and a month – and ended up tackling the chore in August. (Don’t ask.)

Anyway, when I wrote about surveys and corner stakes last year, Charlotte surveyor Jim Massman suggested that it’s a good idea for homeowners to rent or borrow metal detectors to locate official survey irons.

I rented a detector from a nice guy at Cooke Rentals. It was light, easy to use. The fee was just $25.

I practiced on the irons that were clearly marked, so I’d get a feel for the detector. Then I stalked that last iron back in the woods.

The worst parts of the job were (1) mosquitoes, (2) spider webs and (3) scrub hollies with spikes like hypodermic needles.

There are three survey irons across the back of our lot, which is a straight line. Each has been marked by a wooden stake. Theoretically, if I started at the corner I could locate, and stretched a measuring tape directly across the stake in the middle, then I could get pretty close to the problem corner.

Theoretically ...

I had tried that before without the metal detector. I found the remains of a wooden stake at the problem corner, but no iron.

With the detector, I learned that the wooden stake in the middle was off by a few inches. It was off only a little – but that threw my calculation of the problem corner off by a lot.

Massman had warned that, when you set out to locate your survey irons, you can’t just wander aimlessly with the metal detector. You need to have a pretty good idea of the location of the iron you’re looking for. If you don’t, you might mistake an old utility pole ground rod or some such for an official survey iron.

With two of the official irons located and new calculations, I started again.

Turned out the iron was buried under a foot of red clay that landed there when the lot behind us was graded. I had to dig some of the soil away before the detector would locate the iron. Massman also had warned that happens often.

Turned out the old wooden stake there was off by maybe 15 inches.

That’s why you don’t build an expensive fence or structure unti you locate the official survey mark.