How can I make a nail-strewn lawn safe for bare feet? [solved]
Our landlord replaced the roof (cedar shingle) and now there are old nails hidden in the grass all around. My children loved to run around barefoot, but now I'm worried about them getting a nail through the foot.
The landlord used a magnetic floor sweeper and that helped a lot, but we still find nails from time to time.

Is there a way to make it safe it for us to run around barefoot?
Well, the sweeper is a good start. To be even more confidant, a metal detector would find any missed nails. I do think the nails somehow breed when you are not watching, like coat hangars.
A more lo-tech approach would be to use a moss rake, but the prongs might be too widely spaced to guarantee finding all the nails.
Beg, borrow or steal the largest speaker magnet you can find and then drag your yard with it. We used the magnet from a 15' speaker like this after rebuilding our foundation and burning most of the old rotten nail-filled wood. Worked like a charm, though we did need to repeat the exercise a few times (usually in spring as I recall).
Visit your local pro-audio shop, or any outfit that provides sound reinforcement for live music, conferences, etc. and see if they have any dead speakers in storage or the trash bin. I'd offer ours, except the shipping fees would be deadly, probably weighs >20 lbs. :)
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