· Michael Blair
Exterior paint in Middle Tennessee takes UV, humidity and a large annual temperature swing. Good paint on properly prepared substrate handles all of it for the better part of a decade. Paint that fails in two or three years is reporting a preparation problem.
Reading the failure
Peeling down to bare wood means moisture got behind the film. Peeling that leaves earlier paint layers intact means adhesion failure between coats, usually from painting over chalk or a glossy surface without deglossing.
Blistering that appears in summer sun on a south wall is moisture vapour pushing through. Chalking, a powdery residue on your hand, is normal UV breakdown and is a repaint signal rather than a defect.
Where the moisture comes from
Rarely from rain on the paint. It is usually vapour from inside the house, or water entering at a failed joint, a missing kick-out flashing, or a gutter overflowing behind the fascia.
That is why repainting a peeling area without finding the water source produces the same failure on the same wall. Paint is not a waterproofing product.
What preparation actually means
Washing to remove chalk, mildew and dirt, then scraping to sound material, then sanding the edges so the transition is not visible, then priming every bare spot with the right primer for the substrate.
Caulking comes after priming, not before, because caulk adheres better to primed surfaces and will not be sealing over raw wood that then absorbs moisture.
- Wash and let dry fully, at least a day in our humidity
- Scrape to sound paint, then feather-sand the edges
- Spot-prime bare wood and any tannin-bleeding species
- Caulk after priming, not before
- Two finish coats, not one thick one
Timing a Nashville exterior
Most exterior coatings want surface temperature between roughly 50 and 90°F and falling humidity. Middle Tennessee gives that reliably in spring and early autumn.
Avoid painting a wall in direct sun. The film skins over before the solvent leaves, which traps it and gives you early failure on precisely the elevation that gets the most UV.