After the Contractors Leave, Run a Magnet Over the Yard for Nails

The roofers packed up on Friday. They swept, or said they did. On Sunday you find a roofing nail in the gravel by the back step, point up, right where the kids run out to the trampoline.

If a roof, gutters, a deck, a fence or an addition was just finished at your place, there's one tool to buy before the first flat tyre. It's a magnet on wheels. You push it like a broom, and the yard hands over what the crew left behind.

Didn't the crew already sweep?

Probably. It doesn't matter much. In r/daddit, one homeowner's roofers "did sweep with magnets" and still left nails everywhere.

Another had gutters put on and spent months "picking up metal shards" and screws.

A third had a new roof, and the crew "supposedly had done multiple sweeps" with their own magnets. They went over the lawn with an old metal detector and found a bunch more.

Over in r/homeowners, someone whose roofers used a magnet "still ended up finding a few nails".

One commenter's wife has a phrase for it: construction crews "leak nails and screws". They found them on their driveway for years.

The post that started the daddit thread makes the best case for owning one. Their contractors had done a decent job of cleaning up. They still felt silly pushing a magnet along the house for the neighbours to see.

I felt a fool for buying a magnetic sweeper and running it along the outside of my house for passerbyers to see, but within the first couple minutes it paid for itself.
u/misterneem, in r/daddit

Their reasons were a small kid and a flat tyre. Nobody else in these threads strays far from that list: tyres, bare feet, kids and dogs.

One dad bought one "after two flat tires". Another took "a screw through the heel" first.

What is a magnetic sweeper?

A bar magnet in a housing, two wheels and a long handle. You push it across the ground, and nails, screws, staples and drill bits jump up and stick to the underside. The better ones have a release lever on the handle. Pull it and the whole load drops off, so you're not picking nails off a magnet by hand.

The Neiko 24-inch rolling sweeper is that shape, and one owner in r/HomeImprovement says theirs "will grab something that's just below the surface" now and then.

Master Magnetics makes a 24-inch push sweeper with a release as well, and the daddit poster vouches for their magnets as "as strong as advertised". No thread crowns a winner. Pick by width and the lever, not the badge.

If yours has no lever, a daddit commenter has a trick. Wrap a rag or a plastic bag over the magnet before you start, then "pull the wrap off" and everything comes away with it.

The same yard, the ladder and shingles still by the wall: Digby pushes a long-handled sweeper along the gravel strip, focused on the job, nails and screws clinging to the underside of the bar.

What comes up is the surprising part. One family that added on to their house ran a sweeper almost daily for the first month and filled "2 big coffee cans" with nails, staples and screws.

In r/homeowners, someone found "two water bottles worth", including seven-inch nails that must once have held part of the house up.

A homeowner who'd had major work done pulled rusty knife blades out of their driveway gravel along with the screws. They park on that gravel.

Just the number of screws I pulled out of the gravel where I park my car makes me confident that the sweeper more than paid for itself in tyres.
u/prolixia, in r/daddit

Does it work on grass and gravel?

Mostly, with one caveat. The daddit poster's worked "on pavement, lawn, gravel, and dirt". One reply disagreed: on anything but a flat surface, "the bottom of the magnet scrapes" the ground and the thing becomes almost unusable. Two people, one each way. Expect it to be happiest on a driveway and a mown lawn, and lift it over the rough bits.

It only reaches the surface. In r/HomeImprovement, one commenter says a magnet "pulls up nails at a thinner depth" of soil than a metal detector can find metal.

Someone who uses one at a landfill says it "definitely doesn't get it all" in gravel and dirt.

Two things it can't touch at all. Aluminium and stainless steel don't stick to a magnet, so aluminium nails and some deck screws stay where they are. Glass stays too. Two people in the r/homeowners thread wished for a version that worked on it, because they "keep finding shards" after every clean-up.

How long will you keep finding nails?

Longer than feels reasonable. Seven years after moving into a new build, one daddit commenter "still occasionally" finds nails and screws in the gravel by the house.

Another warns you'll be finding them "for a long while" even after several passes over the yard.

Rain keeps bringing things up. The commenter with the screw in their heel runs their sweeper "again every 6 months or so" for whatever it has exposed.

Treat it as a routine rather than a one-off. Run it every day or two for the first couple of weeks, while the ground is still giving things up. Again after the first hard rain, and then once or twice a year before barefoot season.

Before you buy one

Ask the crew first. Contractors are expected to run a magnet after any job. One daddit commenter says to "build it into the contract", and to ask for a daily sweep rather than one at the end.
Borrow one if the yard is small. "It's not something you'll use all the time", says the commenter who runs theirs twice a year. Another family "checked one out" from their library.
About two feet wide. In r/Tools, one owner of a 22-inch calls it "great for garage and driveway" and found the 17-inch a bit too small. Another with the same size wanted "narrower" between the plants and wider on the driveway, which is the whole trade-off. Four others in that thread argue for the smaller one: the big ones are heavy, awkward to unload and take up space.
Get the lever. The release is the part people mention. One 24-inch owner in r/homeowners describes theirs as two wheels, a handle and "a lever to release" what the magnet picks up. Worth the buy, they say.

The same gravel strip from the same angle, the ladder gone: Digby holds up a coffee can bristling with nails and screws, beaming, the sweeper leaning against the wall beside him and the child's ball still on the lawn.

Go for the two-foot class with a release lever. The Neiko 24-inch is the brand and width one owner in these threads uses, and the Master Magnetics 24-inch carries the magnets the daddit poster vouches for. Order it before the crew's last day, so it's by the door for the first pass the evening they leave. Then keep a coffee can beside it for what comes up.