The culprits can be dissimilar materials not caulked together, such as wood and concrete near a foundation, or metal and wood around windows, or similar surfaces, such as overhangs. This leads back to the first point about standing water or water vapors. Ridges around windows and pockets where water can accumulate will cause damage, and that most likely sooner rather than later. This one at first may not be as obvious, and can be expensive to fix. Thirty or 40 years ago when you went to the lumber yard, the lumber you bought had been milled three to four years before it went on sale.
Builders buy the wood before it has greened out, or completely dried out.
Instead, the wood is put through a planer at a high rate of speed, bringing to the surface a waxlike glaze of the tree's inner oils and saps. The glaze won't allow primer to bond to it, so when you paint over it it looks good for awhile, but once the moisture works its way out, the paint peels. Finding a solution comes before the wood gets that coat of primer. Ideally, a painting contractor would allow the wood to dry for a sufficient period before painting, but since that's unrealistic for most jobs, Ross has another suggestion. This is another Ross staple, and one that he recommends for all clapboard houses, either during the construction phase, or after for existing structures.