Hot zinc roof: what to do
Zinc isn't the enemy: the problem is an untreated metal roof, no ceiling, and a dark color. With the right layers, a zinc roof can perform very well.
A zinc roof heats up fast because it's thin and conducts heat very well. The solution isn't replacing it, but reducing absorption (a light reflective coating), cutting radiation (a ceiling and a radiant barrier) and, if rain noise is a problem, adding an insulator that also dampens sound.
Why zinc feels worse
Metal has low thermal mass: it doesn't store heat, it transmits it almost instantly. A concrete slab, on the other hand, delays heat but releases it at night. Neither is inherently good or bad; both improve a lot with a reflective finish and insulation See evidence.
It's light and cheap to retrofit. A reflective coating plus a radiant barrier under the sheet usually gives the biggest comfort jump for the lowest spend.
Your roof could be the point letting in the most heat.
A diagnosis determines exactly which layers your roof needs, without overselling. Gallardía assesses and installs.
◆ Sources for this page
Every important claim links to its evidence. Tap to see the source, its context and its limits: DOE Insulators Radiant barrier. Full bibliography in the evidence library.