The Attic Hatch Check: A Flashlight Walk Under the Roof Boards

Look at the ceiling under the hatch first. FEMA's guidance for going back into a water-damaged house says a sagging ceiling may be holding water above it, and the drywall can come down. A ceiling that bulges or sags is a reason to leave, not to look.

Wet light fixtures or outlets in that room mean getting out of it and calling 911 from somewhere dry. The Department of Energy repair brief says to turn off utilities before inspecting or repairing.

In the attic, step only on joists or on boards laid across them. The drywall between the joists is the ceiling of the room below, and it carries nothing.

The asphalt roofing trade group, in its Superstorm Sandy advice, pointed people to the attic to examine the deck's underside. Water stains are a sign of leakage, and flashings are the most vulnerable points. So the first sweep of the flashlight goes to the boards around the chimney, the vent pipes and any wall where two roof levels meet.

A dark streak running in a line uphill points toward where the water came in. A stain that feels damp is more recent than one that is dry and pale. The Energy Department brief says wood has to read under 20 percent moisture before it is covered, and that is why a stain you can see is only a place to start, not a verdict.

Insulation tells two stories. Wet or matted insulation under a stain means water has been arriving for a while, and the Energy Department brief has wet insulation removed so the ceiling can dry.

Thin, uneven or missing insulation tells the winter story. UMass building researchers put ceilings in northern houses at about R-38, kept continuous. They point to the strip over the tops of the exterior walls, where rafters sit on the wall and leave little room, as a classic heat-loss spot. Keep a tape measure in the attic: a depth in inches, written next to where you measured, is a number a contractor can use on the phone.

The UMass article lists the usual leaks: wire and plumbing holes, light fixtures, attic hatches, chimneys, bathroom fans and the joints where interior partitions meet the ceiling. The federal Building America guide calls sealing those leaks the most important step against ice dams, since warm air keeps the roof deck cold only if it stays out.

The hatch you came through is on the list. So are the box around a bath fan and the chase around a chimney. Look for gaps you can see daylight or insulation edges through, and note each one.

The National Park Service calls flashing the weakest point in any roof and says pinholes alone can let in a lot of water. From the attic, the boards around the chimney are the ones to read: a stain halo, a damp edge, wet insulation beneath.

Measure how far each stain sits from the chimney and on which side, and write that down. It helps the roofer decide between flashing, shingles or something higher up the slope. If daylight shows around the chimney, note it and leave it alone. The same Park Service brief warns that sealant patches harden and crack, so a tube from the hardware store is not the answer.

New Jersey's insurance department asks storm victims to photograph damage before throwing anything away, to keep damaged items until the insurer inspects them, and to save every receipt. The same habits help with a leak that has no storm behind it.

Note the date, the weather that day, the room below and the stain's distance from the chimney or nearest wall. Photograph each find with a tape measure or a coin beside it for scale. A pencil line around a stain, with the date, shows next time whether it grew.

The looking stops at the first wet board, a stain that grew, or daylight where none belongs. That is the point for a roof inspection, and for a roof repair when the cause is plain.

Your move: call (973) 358-8198 with the photos, the date and the stain's distance from the chimney. A wire down, a sagging ceiling or water at a fixture goes to 911 or PSE&G first.