As a firefighter/ paramedic I would advise using gloves and exercising caution especially picking up napkins clothes or any other item that could hide an open needle and easily be punctured.

Insurance: It, in theory, weakens the integrity of the roof because there is something puncturing the roof.

ALSO, over the past 30 years I have had several refers where the tenants decided to defrost the freezer...using a sharp knife or ice pick, and puncturing the cooling lines.

The kitchen sink seems to have a small puncture and some cuts that started rusting (not seen in this photo).

The roofer ended up with 5 punctures which drew blood.

Slower, but leaves an immaculate hole with no rough spots that can snag/puncture my precious AC lines.  

The chair legs can puncture the bottom of the tub causing some pretty serious issues.

Statistically, at 15 - 20 years of age you should be ramping up to yearly inspections, and have funding available by that time to proactively take action before serious damage can occur to other areas of the structure.For those with flat roofs, particularly multi-family structures, they should also be inspected and maintained yearly (including gutters and downspouts) to ensure seams and flashings are properly sealed, as well as any needed minor puncture repairs.

Don't touch it and disturb it, no problem.If I end up buying the deal, asbestos disclosure in the lease becomes mandatory as well as prohibiting tenants from puncturing the wall, etc.  

Once this balloon gets punctured, all of the air comes out.