After a hailstorm most people walk the yard, check the gutters and the siding, then look up at the shingles. The chimney gets less attention. Its cap, the metal or masonry piece sitting on top of the flue, stands above the rest of the roof and takes hail from the storm side. This page covers what hail does to a chimney cap, how to tell a dent that matters from one that does not, and what to have in hand before you ask a roofer to look at it.
Storm and hail: why the cap takes the hit
On most St. Louis houses the chimney cap is often the highest piece of metal on the roof, and hail driven by wind hits it from the storm side first. Caps made of thin galvanized steel or aluminum dent easily. Many older brick chimneys have a mortar or concrete crown under a metal or tile top, and hail can crack that crown rather than dent anything. A dent in a metal cap is often cosmetic at first. A split seam or a bent edge is not, because it lets water in above the flue.
Hail season in St. Louis tends to run through the spring and early summer, when warm moist air meets a cold front, and the stones can be small. Smaller stones can still mark a cap if enough of them land on it. What you want to find is shiny bare spots where the coating has come off, small pits in the metal, and an edge bent toward the chimney body. On a concrete crown, look for hairline cracks, flakes of mortar on the roof or in the gutter below, and a top stone that has moved.
Storm and hail: the freeze and thaw problem
A hairline crack that looks harmless in July can open up over one St. Louis winter. Water gets into the crack, freezes, expands and widens it, then thaws and draws in more water. That freeze and thaw cycle is why a crown checked after a storm should be checked again before the first hard freeze, not left until the next leak shows up on the ceiling. If the damage is only a few hairlines, a mason may be able to seal it. If the crown is spalled or the top stone is loose, the repair is larger and the crown may need rebuilding.
Dents in a metal cap do not usually need to be hammered out. They need a judgment about whether the coating has cracked and whether the cap still sits square on the flue. A cap knocked out of position can send water onto the flashing at a new angle, and then the water finds the shingles under the flashing edge. That is why the inspection should look at the cap, the crown, the flashing and the shingles beside them as one area, not as four separate jobs.
Storm and hail: what to photograph from the ground
Start from the yard with your phone. Photograph the cap from each side at a slight upward angle, then the crown from the front and the back of the chimney, then the flashing where the chimney meets the roof. Keep the originals with their timestamps. Do not climb up to take these pictures. The point is to have a before record that shows where the damage sits relative to the storm side.
A roofer who has to go onto the roof to look at the cap should use a harness and tie off to a rated anchor, and should not put weight on a cracked crown. If a crown is loose, the safe way to see the top is from a ladder at the eave or from a lift, not by stepping on the masonry. Ask how the roofer plans to reach the chimney before anyone climbs.
What it costs
A replacement cap is a small part, and the part is rarely what drives the bill. The labor to reach the chimney, the setup, the flashing work and any masonry repair decide most of the total. A crown repair on a brick chimney is masonry work. Depending on the damage, it can need a mason as well as a roofer, and a mason's work is often priced by the hour or by the job rather than by the part.
A fair quote separates the lines. Ask for the cap, the crown and the flashing as separate items, so you can see which work is storm damage and which work is age. A quote that lumps the chimney into one figure inside the roof price makes two bids hard to compare. It also makes it harder to know what your insurer may want to see when you file your own claim.
Keys puts a written scope with photos and measurements in your hands, so you can compare it with other quotes without guessing at what was included. The scope should say where the measurements came from, whether the chimney was counted, and whether masonry is in the price or left out.
What to ask
- Will you photograph the cap and crown from each side before you touch them?
- Does the quote list the cap, the crown and the flashing as separate lines?
- If the crown is cracked, is the masonry in your price, or is it a separate job?
- How will you reach the chimney, and what will you stand on?
- What will you do about the shingles under the flashing edge?
- Will you give me a written scope with photos and measurements before I sign?
Your insurance claim stays with you
Whether chimney cap damage is covered depends on your policy and the wording of your coverage. Missouri law (RSMo 407.725) bars a roofing contractor from representing or negotiating a homeowner's insurance claim, and it bars a contractor from saying anything about paying, waiving or covering a deductible. A roofer can document the damage, put the written scope with photos and measurements in your hands, and attend the inspection as the contractor while you deal with your own insurer. Keep the before photos and the storm date with your file.
Call before the next front
If you see a cracked crown, a loose cap, or a water stain on the chimney wall or in the attic beside the flue after a storm, do not wait for the next rain to tell you whether it is serious. Water running down a flue or into masonry can do damage well beyond the cap itself. Call the Keys office at (314) 220-2333 to set up an inspection, and have your storm date and your photos ready when you call.