Yes, they will work very well.

As Butch said, however, the manufacturer's tuning chart is pretty 
worthless for such an installation. That's because the chart is 
usually for a ground mounted installation, or a roof top with only 4 
or 8 radials.

Two experiences with metal roof top verticals come to mind.

Shortly after my brother and I got into CB radio, I went to spend the 
week with my grandmother in Alabama. Her house had a tin roof, so my 
dad rigged a clamp to fasten the mobile antenna near the edge. We were 
all blown away by how well that temporary setup worked. I could hear 
as well as the guys around me who were running ground plane type 
antennas, and managed a respectable transmit signal too.

When the higher hf bands were beginning to wake up in 1977, a friend 
who ran a furniture and appliance store decided to put a 15 meter 
vertical on the roof of his 4,000 sqft steel building. His vertical 
was made from 2 pieces of tubing which his store was selling as 
"closeline poles." He fastened them together, and installed it on a 
television antenna tripod, using a glass catchup bottle as the base 
insulator between the bottom of the antenna and the roof.

At the time, I was running a Swan 500CX with a 2 element Hi-gain quad 
at 60 feet. My friend was a mile away, running that vertical with a 
Viking Ranger that belonged to his uncle.

He could work anything he could hear with that rig on AM, and he would 
beat me in the pileups 99% of the time with his 75 watts on cw vs my 
300.





Mike Duke, K5XU
American Council of Blind Radio Amateurs