[scho63]

Originally Posted by Why Not?

It's to prevent a phenomenon known as "roof rumble". The roofs are called "bowstring", cause they're built on a roof truss shaped like an archer's bow... flat across the ceiling and arched up slightly in the center of the roof. The wooden trusses are nailed to the top plate of the exterior sidewalls of the home. The sheet metal roof skin is screwed only at the perimeter of the mobile home, along the top plates... NOT across the top of the trusses. This is because the metal roof skin and the wood framing expand and contract at different rates in temperature changes. If the roof skinning was fastened to each truss across the top of the roof, you'd eventually have leaks roof galore. Because the skinning is not fastened across the top of the roof, it tends to rumble whenever a good wind blows up. The weight of the tires prevent the rumbling. I've lived in Fla., Texas, New Hampshire, and Ohio, and it's the same thing everywhere. Watch out in the wintertime though; the tires will fill with rain and snow, and turn to ice, which puts alot of weight strain on your roof trusses.


Got this off of yahoo. I was curious as well

I was starting to think you were really really smart until you stuck those last two sentences in there!