What Do Roof Inspectors Actually Look For?

Seven things: the surface, the underlayment beneath it, the decking under that, the ventilation, every flashing and penetration, the quality of previous repairs, and how many years are left. Only the first is visible from the ground. The other six decide whether a roof gets repaired or replaced, and none of them can be judged from a photograph or a driveway.

Rancho Roofing is a licensed C-39 contractor in Encinitas, CSLB #1153860. This page lists what a proper inspection covers so you can tell whether the one you were given was a real one.

There is a practical reason to know the list. A visit that looks only at the surface produces an opinion. A visit that works through all seven produces a decision you can spend money on.

What does the inspection actually cover?

Seven areas, set out in Cert-A-Roof’s May 2026 framework.

The list is worth having in front of you when somebody comes out, because it is the difference between an inspection and a look.

Ventilation is the item on that list people find surprising. A surface that runs hot underneath ages from below as well as above. A house with blocked intake at the eaves wears out early, for reasons that have nothing to do with the product on top.

What a professional inspection evaluates, from Cert-A-Roof’s repair-versus-replacement guide (4 May 2026). What is checked	What it tells you
Surface condition	Granule loss, tile cracks, metal corrosion, flashing integrity
Underlayment status	The waterproof barrier beneath the surface material
Decking condition	Plywood or board sheathing for rot, sagging, delamination
Ventilation	Poor airflow ages a surface prematurely from below
Flashing and penetrations	Every vent, chimney, and skylight is a potential failure point
Previous repairs	The quality and the quantity of past patches
Remaining life	A data-based estimate of years left

Why is the surface the least important part?

Because the layer under it is what stops water, and it fails on a different schedule.

A tile surface can be sound while the waterproof sheet beneath it has gone. Premium Roofing’s March 2026 figures put clay tile at 50 to 100 years and the underlayment under it at 20 to 35. On a tile house those two clocks are decades apart.

That is why a photograph does not settle anything. The tile in the picture is fine. The question is what is under it, and the only way to answer that is to lift some.

The same logic applies to a shingle surface with a soft deck underneath. From above it looks like a roof. Underfoot it does not.

It cuts the other way too, and this is the part worth holding onto. A surface that looks tired from the street can be sitting on a sound sheet and a dry deck, with years left in it. Judging a roof by its appearance costs homeowners money in both directions.

What does an inspector do that a homeowner cannot?

Get on it safely, open things up, and read what previous repairs mean.

Access is the first thing. Walking a tile surface without breaking it takes practice, and the risk of a fall on a damp morning is not theoretical.

Then opening things up. Lifting tile to see the sheet, checking whether decking is soft, and getting into the attic to look at the underside of the sheathing for staining, damp insulation, or daylight. Those are the checks that produce an answer rather than an impression.

The third is reading history. Cert-A-Roof lists the quality and quantity of previous repairs as its own inspection item, and it is genuinely informative. Three patches in five years around one area says something different from three patches spread across a whole roof.

If nobody lifted anything or went into the attic, what you got was an opinion about the top layer, not an inspection.

What should you receive at the end?

A written report with photographs, findings, and an estimate of remaining life.

Cert-A-Roof’s May 2026 description of a proper inspection is a detailed written report with photos, findings, and an honest recommendation. That recommendation may be a repair, a restoration, or a full replacement.

Photographs matter more than most people expect. They let you compare one contractor’s findings against another’s without climbing anything. They are also the record of what the surface looked like on a given date, if an insurer ever asks.

The remaining-life estimate is the part homeowners most often do not get and most need. It converts a condition report into a plan: whether this is a surface to maintain, one to budget for, or one to replace now.

A quote is not a report. A quote is what follows a report, and it should be possible to take the report to somebody else. For independent guidance rather than a contractor’s opinion, the National Roofing Contractors Association publishes standards. More on timing in when to book one, and we carry out roof inspections.

Does a home inspector check the roof properly?

A general home inspection covers the roof at a level appropriate to a whole-house review, which is not the same as a roofing inspection. Many will not walk a tile surface at all. Few lift material, and fewer estimate remaining life. It is a screening, not an assessment of the roof as a system.

Can an inspection be done from a drone?

A drone photographs the surface well and reaches slopes nobody should walk. It cannot lift a tile, press on a soft deck, or get into the attic. It is a useful part of an inspection and a poor substitute for one.

What does trapped moisture look like on a flat section?

Often nothing, from above. It is found with test cuts, a moisture meter, or an infrared scan after sunset, when wet areas hold heat longer than dry ones. It matters because it decides whether a coating is even an option.

Should I be there during the inspection?

It helps. Being present means you can ask what a finding means while somebody is standing next to it, and you get to see the photographs taken rather than described. It also makes the attic access part straightforward.