Trusted Home Repair Diagnosis Guides

Symptom Guides · roofing

Ceiling Water Stain: Shingle Roof Leak

A ceiling water stain under an asphalt shingle roof means water penetrated the roof (usually through worn shingles or failed flashing) and traveled along framing before soaking the drywall. The leak source is often several feet from the stain.

Symptom Guides · roofing

Roof Ridge Suddenly Sagging?

A sudden sagging ridge on an asphalt shingle roof is usually caused by a structural failure below the surface (a cracked ridge board, loosened rafter ties, or rot from a hidden leak) or by excess weight from extra shingle layers or snow load.

Symptom Guides · roofing

Daylight in Attic: Shingle Roof Causes

Intermittent daylight in an attic means there's a small gap in your asphalt shingle roof deck, flashing, or around a penetration. It only shows at certain sun angles but is still an active leak path that needs sealing.

Symptom Guides · roofing

Chimney Leak Getting Worse? What's Wrong

A worsening leak at a chimney is almost always failed roof flashing: cracked sealant at the counterflashing, lifted step flashing, or a missing chimney cricket letting water pool and force its way in.

Symptom Guides · roofing

Rust Stains Near Roof Flashing

Rust stains at roof flashing in an older home mean the galvanized steel flashing or its fasteners are corroding after 20 to 40 years, thinning the metal and eventually letting water through.

Symptom Guides · roofing

Step Flashing Lifts in Heavy Rain

Lifted step flashing during heavy rain is almost always caused by loose nails, failed sealant, or step pieces that aren't properly overlapped, letting wind-driven water get behind the flashing along a roof-to-wall joint.

Symptom Guides · roofing

Downspout Disconnected in Winter

Your downspout disconnected in winter because ice buildup added weight, the cold made the metal or vinyl contract, or a frozen clog expanded and forced the joint apart. Reconnect it once it thaws and secure it with a self-tapping screw.

Symptom Guides · roofing

Flat Roof Ponding Water in Summer

Ponding water on a flat roof in summer usually means poor drainage from a clogged drain, a sagging deck, or insufficient slope. Standing water plus heat degrades the membrane fast, so it should be cleared and inspected within a couple of days.

Symptom Guides · roofing

Flat Roof Membrane Seam Separation

A flat roof membrane seam separates when the adhesive or heat weld holding two sheets together loses its bond, usually from bad installation, age, or thermal movement. It's an active leak path and should be sealed promptly.

Symptom Guides · roofing

Alligator Cracking on Flat Roof Membrane

Alligator cracking on a flat roof membrane means the surface coating or asphalt has dried out and lost flexibility from years of UV and heat exposure. It's usually a surface-level aging problem fixed by recoating, not an emergency, as long as the cracks haven't let water reach the layers below.

Pillar Guides · roofing

How to Find a Roof Leak

A roof leak is diagnosed by finding the water's entry point, which is usually uphill from the interior stain. Check flashing, pipe boots, and valleys first, since these fail far more often than the shingle field itself.