Serious question, is ground penetrating radar worth the cost for small digs?

We were mapping a potential site in rural Vermont last month, a suspected 19th century farmstead. The budget was tight, so we almost skipped the GPR survey, thinking test pits would be enough. We ended up renting a unit for a day, about $500, and it clearly showed a dense rectangular anomaly just 30 centimeters down. We dug there first and found a perfectly preserved stone foundation, saving us probably two weeks of random test pits. But I've talked to crews who say for small, well-documented sites, the tech is overkill and eats funds better spent on lab work. What's your take? Have you had a clear win or a total waste with GPR on a limited budget?

4 comments

4 Comments

victor2193mo ago

Sounds like your GPR paid for itself in saved digging time.

gray_schmidt83mo ago

What do you mean, @victor219? The time it takes to set up and read the GPR still eats into the day.

the_jason1mo ago

Bring that cost per hour down fast once you start avoiding a few blind dig days. Plus the wear and tear savings on the machine alone is nothing to sneeze at either.

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thompson.robin1mo ago

Oh man, you're actually hitting on a hidden benefit not a lot of folks talk about. It's not just the digging time you save, it's the crew morale. I've seen guys get completely burnt out after a couple of blind dig days where they hit nothing but rock and old pipes. That frustration bleeds into the rest of the job and makes everybody slower. Plus, I've had superintendents tell me the real savings come from not re-scheduling and re-mobilizing a crew after a failed dig day. That's a half-day of paid truck time and standing around that you never see on a spreadsheet. Your mileage may vary, but that hidden downtime adds up fast.