Hail on Crawl Space Vents Gets Skipped, So Photograph Them First

Most homeowners walking the house after a hailstorm look up at the shingles, then at the gutters and the siding. The crawl space vents at the base of the foundation rarely make the list, and on an older St. Louis house they are among the openings a storm hits first on the windward side. A louvered vent sits a few inches above the grade, often half hidden by mulch or a strip of landscape fabric, and behind its louvers is a thin screen of wire or fiberglass mesh. Hail that bounces off a driveway or a patio can reach a low vent as easily as it reaches a roof.

Why the low vents get missed

A foundation vent is small, it sits at knee height, and nobody has to climb anything to see it. That makes it easy to walk past. It also tends to look normal from a few feet away. A louver can be bent inward by a single stone of hail and still look almost straight from the sidewalk. The screen can tear at one corner and still hold its shape. You only see the problem when you crouch down and look at the vent from the side.

Crawl space vents also sit in a different category from the roof in the way the house is built. The roof is the part most people are told to inspect, so it gets the attention. The foundation vent is part of the ventilation of the space under the floor, and in many St. Louis houses that space holds the furnace ducts, the water supply lines and the drain lines. A vent that stops moving air does more than look bad. It changes how the crawl space handles moisture through the year.

What hail does to a louver and a screen

Hail usually leaves a louver in one of three conditions. The blade can be dented, creased or bent back at its edge, which opens a gap wider than the original slot. A plastic louver can crack along a rib or at the point where it snaps into the frame. The third condition is the one people miss: the frame itself is fine, but the fasteners have backed out of the wall or the masonry plug has broken loose. A vent that wobbles when you press it has lost its hold, even if no louver is visibly damaged.

The screen takes a different kind of hit. Wire mesh can be pushed in, flattened or split, and fiberglass mesh can tear along a stress line where the frame bends. A hole the size of a pencil eraser is enough to let in wasps, mice and small insects. A larger tear lets in leaves and wind-blown debris, and in a winter with a hard cold snap it lets in cold air that moves across the floor of the house above.

What to photograph, in order

Take the photos before anyone touches the vent. Start from a few feet back so the foundation line, the grade and the surrounding wall are in the frame. Then move in close. Keep the photos in the same order each time you record the house, so that a later comparison is easy to read.

• A wide shot of each foundation wall that faces the storm direction, with the vent visible and the grade line showing.
• A close shot of each louver from the front, then one from a low angle that shows any inward bend.
• A close shot of each screen, taken straight on and then with the sun behind the vent so that holes and tears show as light spots.
• A shot of each frame corner and each fastener, including any fastener that has backed out or looks loose.
• A shot of the masonry or siding around the vent, since a cracked block or split board is often what the vent is sitting in.

If a vent is hidden by mulch, pull the mulch back and photograph the vent first. The mulch line itself is worth a photo too, because it shows where the grade sits relative to the vent, and that matters later if the vent needs to be replaced and the new one has to sit at the same height.

Measure the opening, not just the damage

A replacement vent has to fit the existing opening. Measure the outside width and height of the frame and note whether the vent is set into block, poured concrete or a wood sill. Write the numbers on paper or in a note on your phone and keep them with the photos. A bent louver can make the opening look bigger than it is, so measure the frame rather than the gap. If the vent is a standard size, the frame measurement is usually enough for a roofer or a contractor to order the right part.

Count the vents too. An older house can have four or five crawl space vents along the foundation, and some of them sit on the side that took no hail at all. The count matters because a written scope should list each opening, and a vague line that says the foundation vents were checked does not tell you which ones were replaced.

Why a torn screen matters before winter

St. Louis winters run through repeated freeze and thaw cycles. A crawl space that gets cold air through a torn vent can see wider temperature swings, and the floor above it can feel colder in the rooms near the foundation. Pipes that run through the crawl space are more exposed when the vent openings are no longer controlled. None of this is a reason to panic, but it is a reason to close the openings before the first hard freeze, not after the first pipe problem.

A torn screen also invites animals. Mice can get through a hole that looks too small for them, and wasps will nest in the gap between a bent louver and the frame. If you find droppings, nests or chewed insulation inside the crawl space, photograph those too and note the date. They belong in the same file as the storm photos, because they show when the opening stopped doing its job.

What to ask a roofer about the foundation

Roof contracts usually focus on the roof, the gutters and the flashing. Foundation vents often sit outside that scope, so ask directly. Ask whether the written scope lists each foundation vent, whether it is included in the price or priced separately, and whether the crew will set the new vent at the existing grade. Ask who will fasten the vent into the masonry and what happens if the masonry is cracked around the opening. If the answer is that the vents are not part of the job, ask who handles them, and get that name in writing.

A good written scope names each vent, describes the damage you recorded, and lists the repair or replacement for each one. It also says whether the photos and measurements will be given to you. Keys Roofing documents damage, puts a written scope with photos and measurements in the homeowner's hands, and attends the walk as the contractor. Whether a foundation vent is covered by a roof contract, a separate trade or a homeowner's own repair is a question to settle before anyone orders parts. Keys can be reached at (314) 220-2333 to talk through what the walk covers.

Missouri law bars a roofing contractor from representing or negotiating a homeowner's insurance claim, so the photos and the scope go to you, and the claim conversation stays between you and your own insurer. A roofer can explain what the damage looks like and what the repair involves. A roofer cannot speak for you to the insurer about what is paid, and cannot offer to cover any part of a deductible.

Keep the file with the rest of the storm photos

Put the foundation vent photos, the measurements and any pest evidence in the same folder as the roof, gutter and siding photos. Name each file with the date and the location, such as north foundation vent, left louver, and keep the original image files rather than screenshots. Note the storm date in the file name or in a short text document that sits beside the photos. When the vent is repaired or replaced, photograph the new vent in the same spots, so that the before and after sit side by side.

Crawl space vents are a small part of a hailstorm, but they are part of the house, and a complete file is the one that covers the whole house. Walk the foundation on a dry day, crouch at each vent, and record what you see before the first freeze of the season closes the window for an easy look.