Ask Whether Your St. Louis Roof Inspection Includes a Water Test

A roof inspection that stays dry tells you what the surface looked like on the day someone walked it. It does not tell you whether water gets past the surface when a storm drives rain sideways into a seam, a nail hole, or a flashing joint. A water test is the step that answers that second question. It is not always included in an inspection, and in St. Louis the question matters, because spring storms often bring wind from the southwest and rain that pushes under the upper course of shingles into details that look intact from the ladder.

What a water test actually does

A water test is simple in principle. One person stands on the roof with a hose and wets a defined section for a set amount of time. A second person stays inside, in the attic or in the room below, and watches the underside of the decking, the rafters near the section being tested, and the ceiling. If water shows up where it should not, the test has found a path, and the crew can narrow down where that path starts.

The order of the test matters more than most homeowners expect. Water runs downhill, so a hose aimed at one section can send water into an area that was not being tested, and that area can then look like a leak even though it was never the target. A careful crew says the order out loud before the hose goes on. Ask them to name the sections, the sequence, and the place where each section ends. A crew that cannot describe its sequence is not ready to run the test.

Common test areas include the valleys, the base of the chimney, the areas around plumbing vent boots, the sidewall where a roof meets a vertical wall, and any skylight or roof window. These are the places where water most often gets under the surface. A test that covers only the open field of the roof misses the places where leaks usually start.

When a water test is worth asking for

Some situations justify a water test more than a standard dry walk. If your ceiling has a stain and nobody has traced its source, a test can help. If a section was repaired before, a test can check whether the repair holds. If you have a skylight, a chimney, or a wall where the roof ends, those are places to test because they are where flashing does its work. A roof that has taken wind-driven rain on one side may also need testing on that side, even if the other side looks sound.

A water test is also useful when the roof is still under a warranty question or when you are comparing two sets of findings. A passed test is a record that a section held water under the conditions tested. It is a stronger record than a photo of a clean shingle, because it shows what the roof did when wet.

What a water test does not prove

A passed test does not certify the whole roof. It covers the sections that were wetted, for the time they were wetted, under the flow the hose produced. A real storm can push water in ways a garden hose cannot match, and a test on a calm afternoon will not reproduce a northwest wind at night. A passed test is evidence for the sections tested, and it should be written that way.

A failed test does not automatically name the failure point either. Water seen in the attic may have traveled along a rafter or a nail line before dripping, so the crew has to trace it. Ask whether the report will name the sections that failed and whether the crew will retest after any repair. Without a retest, you have a list of problems and no proof that the fix worked.

What it costs

The cost of a water test depends on how many sections are tested, how long each one is wetted, and whether the crew needs a second person in the attic for the whole test. Some inspections include a basic test in the visit fee, and others price it as a separate line. Neither arrangement is wrong, but you should know which one you are buying. Ask whether the test is included, and if it is priced separately, ask for the number in writing before anyone climbs the ladder.

Ask also whether a retest after a repair is included. A repair that is tested once and never tested again leaves you guessing about the result, and a retest is often the part that gets quietly left off. If the retest is not included, ask what it would cost and whether the same attic observer would be present.

If you want a water test added to an inspection, call Keys at (314) 220-2333 and name the test in the request, so it is scheduled and priced as its own step instead of being assumed.

What to ask

These questions give you a clear picture before the hose goes on. Write the answers down, because the answers become the basis for comparing any reports you receive later.

1. Which roof sections will be tested, and why those sections were chosen.
2. What order the sections will be tested in, and how the crew will keep water from running into an untested area.
3. How long water will sit on each section before the test moves on.
4. Who will be inside the house watching the attic and the ceiling, and what that person will look for.
5. Whether the written report will include photos, measurements, and the sections that passed as well as the ones that failed.
6. Whether the test is included in the inspection fee, and if not, what it costs.
7. Whether a retest after any repair is included, and who performs it.

Missouri law (RSMo 407.725) forbids a roofing contractor from representing or negotiating your homeowner's insurance claim, so if your insurer asks about a water test, that conversation stays with you and your insurer. What you take into it is the written test record, with dated photos and the sections named, in your own hands.