Hail on Wall Vent Hoods: Check Them Before Winter

Most storm walks stop at the roof, the gutters and the siding, and the small vent hoods on the exterior walls get looked at last or not at all. A dryer exhaust hood, a bathroom fan hood and sometimes a water heater or furnace vent sit on the wall at about head height, and their thin plastic and aluminum faces catch hail the same way the siding does. If you are working out what to do next after a St. Louis hailstorm, these hoods are quick to check and easy to forget, so put them on the list before the next front comes through.

What hail does to a wall hood

Hail rarely punches a clean hole through a hood. What it usually does is crack the plastic louver flaps, dent the aluminum cap, bend the screen so it no longer lies flat, or knock the cap partly out of its bead of caulk. Each of those changes how the hood works. A flap that cannot close lets outside air into the house in winter and lets insects and mice in through the gap. A dented cap can narrow the opening enough to slow the exhaust, and a dryer that runs longer than it used to is often the first sign. Some hoods carry a spring or a hinge that returns the flap, and a bent frame can hold it open or stop it from coming back.

The damage is on the outside, but the symptoms often show up indoors. A load of towels that needs a second cycle, a bathroom that stays damp well after a shower, or a cold draft near the dryer closet all suggest the hood is not moving air the way it should. You do not need to figure out the cause before you photograph the hood. Record what you can see from the outside, and leave the diagnosis for the crew that will do the repair.

Photograph the hood in a fixed order

Start from the ground with the whole wall in frame, so the hood's height and position against the siding are clear. Then move in and take one photo of the hood face straight on. Put a ruler or a tape measure beside the dent or crack so the size is visible, because a dent with no scale tells an inspector very little. Take a third photo at an angle to show whether the cap sits flush or has lifted away from the wall. If you can reach the flap safely, photograph its underside too, since cracks along the hinge often show only from behind.

Note which wall the hood sits on. In St. Louis, a south or west wall takes more of the afternoon sun, and the same wall often faces the direction the storm came from, so the orientation helps explain the pattern in the other photos. Write the storm date in the file name or in your notes, and keep the original image files from your phone. Do not rely on a screenshot of a photo, because a screenshot strips the file details that show when the picture was taken.

Check the flap and the caulk by hand

Once the photos are saved, open the flap by hand and let it go. A sound flap swings closed under its own weight or spring and seals against its stop. Open it, release it and watch. If it sticks, does not return fully, or rattles against the frame, write that down next to the photo. For a dryer hood, you can run the dryer on a short cycle with a helper watching the flap from outside, but only if you can do that safely. Do not climb a ladder you are not comfortable on, and do not use a pressure washer on a cracked hood, because the spray can drive water behind the flap and into the wall.

Then look at the caulk line where the hood meets the siding. Hail can split the bead or lift the cap enough that the gap lets water sit behind it. Check the siding beneath the hood for dark staining, soft spots or drips, and check the wall inside the house near the dryer or the bathroom ceiling for any new moisture marks. These signs mean the hood has moved on the wall, not only that it has taken a dent. Put a photo of each sign in the file.

Separate hail marks from age

Older hoods crack for reasons that have nothing to do with a storm. Sun and the freeze and thaw cycle make plastic flaps brittle after several seasons, and the cracks that come from age look different from the ones hail makes. Hail cracks usually start at a point of impact and spread outward, and they sit on the face of the part that was hit. Age cracks tend to run along the molded lines of the part, show up on several flaps at once, and sit on a surface that looks chalky or faded. Neither pattern is proof on its own. Compare the hood with the other storm marks on the same wall, such as siding dents, gutter dents and screen tears, because hail that hit one of them usually hit the others.

If a hood is old and the cracks look like weather, say so in your notes. Honest notes help whoever reads the file later, and they keep the storm file from claiming more than the evidence shows. A photo of an old, cracked hood with a note that it looks aged is more useful than a set of photos that try to make every crack into hail.

Questions to ask before anyone quotes the hoods

Wall hoods are easy to leave off a roof bid, and they are often quoted as an afterthought. Before you accept a scope, ask the questions that decide whether the hoods are covered.

• Are the wall hoods listed by location in the written scope, with the dryer, the bathroom fan and any other wall vent named separately?
• Will each hood be repaired or replaced, and does the replacement match the throat diameter of the existing duct?
• Who reseals the wall penetration around each hood, and with what kind of exterior caulk for your siding material?
• Does the crew check the duct behind the dryer hood for lint buildup or a separated joint before the dryer goes back on?
• Is each hood photographed before and after the work, with the photos kept in your file?

Ask for the answers in writing. A verbal promise that the hoods are 'taken care of' does not tell you whether the new cap is the same size as the old one, or whether the caulk is included in the price. If the hoods are a separate line, ask what that line costs and whether it appears on the same page as the roof.

Keep the hoods in the same file as the roof

The wall hoods belong in the same photo file as the roof, the gutters and the siding, and they should carry the same dates and orientation notes. One folder with every storm mark, labeled by wall, is easier to read than separate folders for the roof and the rest of the house. Missouri law (RSMo 407.725) forbids a roofing contractor from representing or negotiating your insurance claim. What Keys does instead is document the damage, put a written scope with photos and measurements in your hands, and attend as the contractor while you deal with your own insurer.

Winter matters more for a stuck dryer flap than for almost anything else on the wall, because the dryer runs more and the cold air comes in. If you want the hoods checked during a roof walk, call the Keys office at (314) 220-2333 and tell them which walls have hoods. Get the list done before the first hard freeze, and keep the photos with the rest of the storm file.