I tested some metallic layering of iron oxide and...

I made a quick mix of iron oxide black pigment into some water-based ink and put a small mixture on some pvc magnet material and on the back of some magnet material. The mixture was attracted to a magnet, or vice versa, and to see just how strong the attraction was I put a little on a piece of paper. The magnetic force of a small amount of iron oxide in contact with magnet was enough to suspend a 30 mil magnet upside down through the paper.

My brief research indicated that magnets may lose 1% of their power over a ten year period of time and that magnets would require a coating to survive outside. I layered some magnet pieces and as thin shingles they seem to have the ability to cover a space and layer appropriately to hold themselves down on a metallic surface and be able to provide a shield to the subsurface they are on. My next step is going to be to coat some screens using atomized steel in a thin mixture of epoxy and create a test surface that would imitate sheet steel. Steel is commonly used for roofs with inexpensive sheet metal construction, so this is not unreasonable, but the metals are typically galvanized or coated to keep them from rusting. Sheet metal construction of buildings is typically done for low cost structures like work sheds and storage facilities. I assumed that mobile homes were made of aluminum, but it is possible that sheet metal is used for those types of structures too, without shingles.

To think of putting shingles on metal buildings is a redundant concept since metal is strong enough to withstand most forms of weathering. Still, it is a theoretical concept that I am working with and not practical reality. The only reason I am considering metal is because it is a surface that magnets will bond to and theoretically I can make a thinner version of a metallic surface with a cold cast layer of epoxy and steel particles versus buying sheet metal. This type of coating would also be lighter than sheet steel, before the magnets are applied as shingles. Designs can be applied inside the coated surface and the exterior could be covered with epoxy coated magnets. The epoxy layering may also make the structure less vulnerable to lightning, although wind could be an issue for the magnetic shingles.