White paint roof cooling experiment
I’m currently living in a recycled house that we call Villa Delicioso, and it has been extremely hot inside, even with 4-inch fiberglass insulation, an overhanging roof, an attic space, and all the windows open.
Years ago, an architect here told me that ONLY bright white paint will keep a metal roof cool, and our roof is slightly grey. Mid-day, it’s very hot to the touch, and so is the ceiling inside.
So, we used some leftover oil-based bright white shiny paint and tested a roof panel, as shown in the photo. Sure enough, it was much cooler after hours in the sun!
We painted the rest of the roof, and now the entire house is much more comfortable.
Note: this would save a house thousands in AC bills.