I recently hung out with a couple of guys that I consider monster construction site detectorists here in middle Tennessee. After a few drinks, they told me all their secrets. And with their ok, now I’m telling you:
Get to Know the Builders
Don’t be that guy sneaking on a site because you think they don’t care. Many builders are really cool and appreciate the history of the sites and relics you are trying to save and will give you useful information, and maybe even have someone call you when dirt is moving.
Use Google Earth
The satellite images on Google Earth are not live or up to date. If you see your best friends car in your driveway while you were out detecting, you need to, for example, ask your wife what happened a few weeks ago, not today. So you will almost certainly be able to see a construction site as it was before they began. You can see where structures were, what their shapes were, and where the areas most likely to hold good finds might be, such as the front yard and backyard of a house.
Google Earth is stand alone software you can install on your computer, or you can use a simple version of it and see satellite photos on Google Maps on the web.
Multi-Lot Tearout Tips
A large development, such as an apartment complex, may be being built over places where many houses were torn down. If the development is on a battlefield, detectorists will likely start hitting the property as the houses are torn down. Once the dozers start moving to clear the entire property, hunt where property lines were between the houses. Often un-huntable hedgerows were removed at this point. Those are the places to hit. You can look at properties across the street to line up where the property lines most likely were. Also you can look for ground with roots and sticks sticking out from where heavy vegetation was removed. This is where hedges and small trees were removed.
Concentrate on Hot Spots
Once heavy equipment begins grading a site, the topography maybe be levelled. Some areas will be graded to a perfect level that exposes excellent finds to the detector. Others will be graded too much or not enough. When you find something good, it is important to slow down and cover the area around the find thoroughly to not only find other keepers, but to make sure you are detecting this perfect depth area perfectly, before it is subjected to further grading.
Don’t Detect the Surface of the Moon
On some sites, all or part of the site may be graded way too deep, and all relics are gone. I call this “the surface of the moon”. No signals. Maybe you’ll find some Mastadon bones but typically nothing metal. Hunt the site before it is graded down too deep else like Dirt Girl says, you are “late to the party.”
Talk to Other Detectorists
Not every detectorist is super secretive. Usually at a good construction site there is plenty for everybody, and many detectorists, especially once they feel like they’ve found a lot, will share info and give advice. Sometimes I’ll just walk up to a guy and if he’s been lucky, I’ll just straight up ask “where do you think I should start?” Almost always I’ll get on a good spot – whether the detectorists meant it, or was just trying to get me out of the way. It’s not crazy if it works, right?
Often if you are late to the party and the site has been graded to much, you can still find a few items in the giant dirt piles that are inevitably piled up at construction sites. If they are moving the dirt off-site, you can hunt the piles over and over again as they are reduced, and you can also find where the dirt is being taken and hopefully detect there as well.
Right Coil Size
For small construction sites, like a single lot tearout, I expect a ton of trash and use the smallest coil available to get in between the trash and get what I am looking for. On larger construction sites, there may be a lot of trash but there is so much ground to cover I opt for a larger coil to cover more ground quickly, and maybe use the small coil in the really trashy parts of the site, such as around the actual footprints of any structures that were removed.
Be there First when the Dumpsters and other Obstacles are Moved or Removed
This is one of my own “patented secret’ tips I probably shouldn’t share. After all the detectorists have hunted a really awesome construction site that has produced a lot of finds to death, if the site has a dumpster or dumpsters for the workers to discard material scraps etc in, I’ll watch and wait and try to be there when the dumpster is removed. This is usually weeks later after construction is close to completion. Sometimes if you know a worker or the builder, he may give you an idea of when it will be removed. Hunting the spot where the dumpster had been at two different construction sites netted me two .69 caliber Minie Balls, a Spencer Carbine bullet, and an Indian Head cent last year.
TALK TO THE OPERATORS
The operators can help you understand what they are doing and the timeframe so you can plan and understand when and where to hit certain areas, as well as know when it will be too late to hit certain parts. If you have spots that have produced relics and you wish it was graded a little deeper, lots of time they will move dirt for you! On large construction sites, operators can also share intel as to where they’ve seen pottery and debris on top of the ground, or whether they have found anything great on top of the ground themselves.