Staining and rot on fascia boards directly behind a gutter suggest:

Rot on the fascia behind a gutter is a location clue. Water reaching that surface has to have gone over or behind the gutter's back edge rather than through it, and there are three usual routes: the gutter is blocked and overflowing, and some of the overflow runs backward; the gutter has pitched backward as hangers loosened, so water rides against the fascia; or there is no drip edge, so runoff wraps around the shingle edge and lands behind the trough instead of in it. All three keep the fascia wet in a location that is shaded, slow to dry and hidden behind the gutter, which is why the decay is usually advanced before anyone notices. The inspector reports the rot and looks for which of the three mechanisms is feeding it, since the remedy differs and repainting the fascia without addressing the water guarantees a repeat.

Water on the fascia behind a gutter got there by going over or behind the back edge, whether from overflow, a backward pitch or missing drip edge. The location is what identifies the mechanism.

Gutters must pitch toward downspouts and sit below the roof edge so runoff enters the trough. Drip edge directs water off the roof edge into the gutter. Failures in any of these allow water behind the gutter where the fascia stays wet and decays.

Behind the Gutter Means Over or Around. Blocked, backward, or no drip edge — three routes, one wet fascia.

Probe the fascia rather than judging by appearance. Paint frequently looks sound over wood that has gone soft behind it.

• •Blaming the paint for decay caused by water
• •Accepting fascia rot as normal weathering
• •Repairing the fascia without correcting the water route