Some older St. Louis houses, and a few newer ones where the owner wanted one, still carry a lightning rod along the ridge, the chimney or a gable. After a hailstorm, many people walk the shingles, the gutters and the vent hoods, and the rod gets a glance from the yard. A rod can take a hard hit and still look upright from the ground, so the check has to be done close up, on the roof or from a ladder placed clear of the eave, by someone who knows what a bonded system should look like.
Storm and hail
A lightning protection system works as a set of connected parts. The air terminals are the rods or blunt tips on the high points. A mast or standoffs hold them above the roof surface. A conductor cable carries strike energy down the house to the ground system at the base, and clamps and bonds tie the cable to the terminals and to any large metal on the roof, such as a metal chimney cap, a flashing run or a gutter. Hail can damage any of those parts, and the damage that matters is not always the damage you can see.
The air terminal is usually the first part to show hail. It stands above everything else, so it takes the stones first. Look for a dent that has flattened the tip, a bend that has pushed the rod off plumb, a cracked or split tip, or a loose base where the mast meets the roof. A bent terminal can often be straightened or replaced by the installer, but straightening it yourself on a wet or steep roof is a good way to end up on the ground. Leave that step to the installer.
The bond and the cable
The bond is where a system often fails without anyone noticing. A bond is the connection that ties the system to metal parts sitting on the roof, usually a clamp with a short cable or strap. Hail can knock a clamp loose, bend a strap, or pull a cable out of its clamp. A cable that is kinked, pinched or pulled away from its fastener will still look fine from the ground. Ask the person checking the system to test the bond connections and to note any clamp that has moved, not only the rod tips.
The base and the ground
Hail rarely reaches the ground system at the base, but a storm season can still expose it. Heavy rain washes soil away from a ground rod or ground plate, and downspout runoff can cut a channel near a footing. Check whether the down conductor is still fastened at the wall, whether the cable has been pulled out of its clip at the eave, and whether any connection at the base has been disturbed by digging or a new gutter run. St. Louis clay holds water and shifts, so a base that sat level and firm can settle over a few seasons.
Take the photographs before anyone touches the rod. From the yard, use a zoom lens or the telephoto setting on a phone and shoot the rod at a few angles, with the house in the frame so the position is clear. Shoot the mast base and any clamp you can reach safely from a ladder you can hold steady. Write the date on each set and keep the original files on the phone rather than screenshots, so the timestamps stay intact. Do the check on a dry day when the shingles are cool, because wet or hot shingles make any walk on the roof unsafe.
What it costs
The cost of a lightning rod repair depends on what the check finds. A system where the only problem is a dented tip or a loose clamp is usually a small job, covering the trip up to the rod and the parts that were damaged. A system where the cable has been cut, a whole run has come away from its mast, or the base needs new ground work is a larger job, and it may not be a repair at all. The price also rises with the height of the house, the number of terminals to reset, and whether roof work around the rod has to happen at the same time.
Ask the installer to price each part on its own line. A single lump sum hides the difference between straightening a tip and replacing a cable run, and that difference is what you need to understand before you decide whether to repair or replace the system. Ask whether the price includes a final test and a written report of what was tested. A rod repaired without a test leaves you guessing about the bond.
If the roof itself is being replaced, the cost picture changes. The rod has to be detached from the roof area where the new shingles go, and it has to be reconnected correctly afterward. Ask whether that reconnection is in the roof bid or in a separate lightning job, because a line that appears in neither place is the one that gets missed.
What to ask
Before you agree to anything on a lightning rod, get answers to these questions in writing:
- Which standard was the system installed to, and does the installer's report say so? Many systems are built to a published standard such as NFPA 780, and the answer tells you what a correct repair looks like.
- Which terminals, clamps and bonds were checked, and which ones were found moved, bent, cracked or loose?
- Will each terminal, each clamp and the base be photographed from the ground and labeled so the photos match the written list?
- Who reconnects the rod when the roof comes off, and is that line in the roof bid or in a separate lightning job?
- Is a final test included, and what does the written report say was tested?
- What training or certification does the person working on the system hold for lightning protection work? Missouri has no state roofing licence, so that answer has to come from the installer and should be put in writing.
If a roofer is already on your roof writing up hail damage, ask whether the rod is on the scope. Keys Roofing documents damage and puts a written scope with photos and measurements in the homeowner's hands, and the office can be reached at (314) 220-2333. Missouri law (RSMo 407.725) bars a roofing contractor from representing or negotiating a homeowner's insurance claim, so the photos and the scope belong to you to take to your own insurer or to anyone else you choose.