On the market, there are available two types of metal trusses- flat structure and with structure with the slope.Aluminum roof truss are usually much more expensive than timber trusses. Although they tend to serve a little longer, they occasionally require maintenance. Experienced professionals will be able to build it quickly and efficiently, but their installation requires a lot of skills, practices and resources. The metal does not tolerate heat as well as wood, so it can expand and cause damage to the roof at very high temperatures. At 400-500 degrees, it loses up to 50% of its strength. If you want better sound insulation, then the aluminium roof truss will not be the best solution. And, of course, everyone knows that the metal is rusty, so it requires proper maintenance, which is undoubtedly more expensive than the maintenance of wooden trusses.
Pluses:
Resistant to cold weather;
A large part of the metal trusses consists of recycled material.
Minuses:
Rust (requires frequent maintenance);
Due to the rapid heating of the metal, careful thermal insulation in the roof structure is required.