Having been involved in several roofing jobs over the years - and with a neighbor who is a professional roofer - and family members in the construction business - I've tried many nail collection methods. When a crew of 14 roofers rips off old shingles and completes a 50-square job (150 bundles) in one day, nails are going to fly. Ground conditions vary widely around most houses. Non-concrete surfaces also vary according to how wet the ground is. Nails become embedded in wet soil, leaves, mulch and grass and stick like they were in glue. Most professional roofers do not collect nails. That's not how they make their money. Most of them use light drag magnets without wheels. They make one swift sweep and leave. Therefore, it is up to the homeowner. One of my hobbies is lawn care. I can't afford to run a large, expensive commercial mower around a house that has recently had a roofing job without first making certain that the ground is free of nails. Having said all of this, there is no perfect collection method for all surfaces. First off, the magnetic bar inside this 24" sweeper is not designed to be adjusted. Even if it was, it would only make it less effective by keeping the magnet further away from the nails and failing to lift them out of the dirt. This sweeper is an aluminum housing with a magnetic bar inside. When the handle on top of the housing is lifted, it raises the bar from the bottom of the housing and releases the nails. The best idea would be to have large, adjustable wheels that can be easily raised or lowered based on surface conditions, along with a powerful magnet about three times stronger than this one. It would be heavy. With this 24" sweeper, cleaning concrete is a breeze. No sweat. One sweep, maybe two, and it is done. However, sweeping grass, leaves and dirt is a whole different story. Several sweeps are require over a period of weeks until no clicks are heard. This is especially true if the ground was wet when the roofing job was done. Sweep after the soil dries and then again after a good rain. Eventually, the clicks of nails impacting the sweeper will cease. During my initial sweeps when dozens of nails are collected every few feet - and especially on large jobs - I set up several dumping stations around the house. Plastic trays about 26" long that the sweeper will fit inside or tarps work well to catch the nails. When the clicks of metal against metal become less frequent, it is easier for me to wear a belt or shoulder pouch and turn the sweeper up on one wheel and pick off the nails by hand. And in extra thick grass, mulch and leaves, I then pull out a 6-pound, 10" magnet on a rope designed to lift boat motors weighing up to 300 pounds from lake bottoms. Dragging and swinging it is tons work. It takes time, effort and a lot of sweat. Cleaning off the nails is a challenge, but there will be nails. You can count on it. And the deeper the leaves and mulch, the more nails you will find. In addition, you'll need to pick up all the chunks of broken shingles by hand. There will be many. You'll be surprised how often you discover a nail embedded in a shard of shingle that the magnet failed collect. Bottom line is made in three points: 1. This 24" Magnetic Sweeper is definitely worth the money. 2. No sweeper is perfect is all conditions. 3. Know what to expect.
