Why the inside tells you more than the outside
A roof covering is designed to be looked at. It is cleaned, it is walked, it gets replaced in sections, and it hides its own history. Underlayment covers the deck, the deck covers the framing, and anything that happened in between is buried under the surface somebody is standing on.
The underside hides nothing. Every time water has come through, it left a mark on bare wood. Every nail that has been damp is rusted. Insulation that has been soaked and dried stays compressed in that spot. None of that gets cleaned off and none of it gets covered over, so the attic holds a record going back years while the outside only shows you today.
That is also why a roofer asks for the attic before quoting anything. A covering can look serviceable from a ladder while the deck under it has been taking water at one penetration for three seasons. The reverse happens too — a tired-looking roof with a bone-dry deck underneath is usually a repair rather than a replacement.
The outside of a roof shows you today. The underside shows you every wet year it has had.
How to look without making it worse
Pick a dry day and a cool part of it. A Florida attic in the afternoon runs far hotter than the air outside and heat exhaustion up there is a real hazard, especially alone. Early morning is the time to do this.
Take a bright flashlight, not a phone light. You are looking for color differences on dark wood and a phone screen will not show them. Point the beam along the rafters and across the deck rather than straight at it — raking light picks up staining and surface texture that a direct beam washes out.
Stay where there is something solid to stand on. If the hatch opens into a space with no platform, look from the opening and go no further. Walking ceiling joists is how people put a leg through a ceiling, and kneeling on blown insulation crushes it so it stops working in that spot permanently. If you cannot see it from the hatch, you cannot see it, and that is an acceptable answer.
Keep a mask on if the insulation is old or there is visible mold staining, and come out if you find droppings, wiring you do not recognize, or any smell of gas. None of that is a roof problem and all of it is a reason to stop.
What you are actually looking for
Daylight through the deck. Any pinhole of light where there should be none is a hole in the roof assembly. Look at the ridge, at valleys, and around every penetration. Note that ridge vents and soffit vents are meant to let light in, so learn where those are first — otherwise you will photograph working ventilation as a defect.
Water tracks and tide lines. Fresh water staining on wood is dark and has a defined edge. Repeated wetting leaves a series of edges, like rings in a cup, each one a high-water mark from a separate event. A single dark ring around a pipe penetration is usually one failed boot. Several faint lines running down a rafter mean it has been happening for a long time.
Rusted nails and backed-out fasteners. Nail points coming through the deck should be dry and clean. Rust on the point means that nail has been wet, and it is a reliable marker for where water is getting in even after the stain has faded. A nail head you can see pushed back out of the deck means the fastening is failing there, whatever the covering looks like from above.
Soft or delaminated plywood. From underneath, failing sheathing looks darker, sometimes slightly sagged between rafters, and the plies separate at the edges. Shine the light along the underside of the deck and look for a patch that reads different from the wood around it. Do not push on it to test. If it is soft, pushing makes the hole.
Insulation, mold staining and the ventilation nobody checks
Insulation is the best water record in the attic because it does not recover. Batts that have been wet are flattened, discolored and sometimes crusted on top. Blown insulation that has taken water sits in a depression with a crust over it. Wet insulation also stops insulating, so a patch like that is costing you on the power bill whether or not the leak is still active.
Dark staining at the eaves, where the roof meets the wall plate, is common in this climate and it is not always a leak. It is frequently condensation — humid outside air meeting a cold-ish surface, over and over, in a corner with no airflow. A roofer tells the difference by where the staining sits relative to the deck and the penetrations, and by whether the insulation under it has ever been saturated.
Then look at the ventilation, because it is the finding most often missed and the one that quietly does the most damage. At the eaves, check whether the soffit vents are actually open from the inside. In plenty of Spring Hill houses the insulation has been pushed or blown right out into the eave and sealed the intake shut. At the ridge, check that the vent has a continuous slot cut in the deck under it rather than sitting over solid plywood.
A roof with blocked intake cannot move air. Heat and moisture stack up against the underside of the deck, the attic runs far hotter than it should, and the covering above cooks from below as well as from the sun. Fixing a soffit blockage is small work. Leaving it shortens everything above it and makes a roof look prematurely worn for a reason nobody can see from the driveway.
Blocked soffit vents are cheap to fix and expensive to ignore. The roof above them is being cooked from both sides.
Call now, or watch it
Call now: active dripping or running water, daylight visible anywhere that is not a designed vent, deck that is visibly sagging between rafters, a wet area that is spreading between two looks a week apart, or heavy mold growth across the sheathing rather than a stain in one corner. Those are either letting water in today or hiding structure that has already given up.
Watch it: a single old dry stain with a crisp edge and no fresh darkness, a few rusted nail points in one area with dry wood around them, light surface discoloration at the eaves with dry insulation underneath. Mark the edge of the stain with a pencil, date it, and look again after the next heavy rain. If the pencil line is still the edge, it is history rather than a problem.
Photograph both kinds. Wide shot first so the location is identifiable later, then close. Get the rafter or truss in frame for scale, shoot with the flashlight raking across the surface rather than head-on, and include whatever is nearby that fixes the position — a pipe, a vent, the hatch. Stains photograph badly, so take more than you think you need and do not delete the ones that look repetitive.
Be honest with yourself about access. A lot of houses here have a hatch in a closet ceiling, no platform, low clearance at the eaves and ductwork across the middle, which means most of the attic simply cannot be seen. And some findings cannot be confirmed from below at all — soft decking, a lifted covering and a failed fastening pattern are confirmed from above, with the material lifted. An attic look narrows down where to go. It does not close the question.
What we do is look from both sides, photograph what is there, and put the condition and what it would take to fix it in writing before anyone quotes. That is a general assessment of roof condition and nothing more — we do not perform, complete or sign four-point or wind mitigation inspections, because a roofing license does not qualify anyone to do either. Work performed by GenX Roofing LLC, Florida Certified Roofing Contractor, license CCC1333347.