Listol Painting, Inc.has completed many repaint projects working with factory painted steel building walls and roofs. The years of sun takes its abuse fading and eventually deteriorating the steel finish into oblivion. Today’s post focuses on two subjects: how to paint steel building walls and how to paint a steel roof.
Walls need to be prepped correctly, and I start by sanding the rough and/or rusty areas out with a Random Orbital Sander using a fine finish sanding pad (about 200 grit) until the area is clean and ready for your primer coat. I like using a direct to metal primer and spot prime it. Follow your process by power washing the entire area to be painted to make sure that you have a clean, dirt free surface to paint. After it dries (give it about a day), apply two coats of an excellent finish made for the surface. My favorite product to use is Sherwin Williams A-100 Satin finish – I have used this on buildings over 30 years ago and it STILL looks good, which is phenomenal in my opinion. Another good product is Sherwin Williams Direct To Metal (DTM) in a satin or higher finish.
Painting a roof takes the same preparation as noted above, and the finish can be a DTM or Sherwin-Williams Sher-Cryl as well, but I do not recommend it due to the extreme temperature swings that are here in Arizona. There are better finishes such as Rust-Oleum Oil Based Enamel. The colors are not very good for fading issues, but it sticks very good. Using an oil based paint can be a challenge due to its issues with clean-up, but overall, my choice would be this method. To try to eliminate fading issues, try to use a light color as a dark color will fade so much faster. Always apply two coats to your finish for the best coverage.
Whenever you are spraying either walls or roofs, always use a very fine finish spray tip, and my favorite tip to use is a Graco Rac-X 1210. Using this with filtered paint at a medium or higher pressure set on your airless sprayer will give you the right amount of paint delivery without having any runs or sags in your finish. I will cover sprayers at a later blog