How Snow and Ice Loads Can Damage Your Home's Service Entrance

October 9, 2026 · Family-owned electricians in North Idaho

Public domain, via Wikimedia Commons

If a chunk of roof snow or ice has come down hard on the wire running to your house, or you've noticed the metal mast on your roofline leaning, bent, or pulled away from the siding after a big storm, you're looking at service entrance damage. This is the point where the utility's power line connects to your home, and it takes more abuse every winter than most homeowners realize.

Most likely cause

The most common cause is sliding snow or falling ice hitting the service mast or the drop wire itself. In North Idaho, metal roofs and steep pitches shed snow fast, and a few feet of heavy wet snow coming off the roof edge can hit the mast, the weatherhead, or the wire with real force. Ice buildup on the wire adds weight too. A wire that's rated to carry its own weight plus a little wind can sag badly or pull hard on the mast when it's coated in an inch of ice.

To confirm this is what happened, look at the mast where it exits the roof. Is it leaning compared to how it sat last fall? Check the weatherhead (the fitting at the top where the wires come out) for a gap or crack at the roof flashing. Look at the meter base on the side of the house for pull marks, gaps, or a socket that looks shifted. If you see fresh scrape marks on the siding near the mast, or snow and ice debris piled right at the base, that's a strong sign the mast took a direct hit.

Less common causes

A few other things can cause the same kind of damage, and it's worth ruling them out because the fix is different.

• Undersized or poorly braced original installation. Older homes and cabins sometimes have a mast that was adequate when it was installed but was never rated for the load it's seeing now, especially if a metal roof was added later that sheds snow faster than the old shingle roof did. Confirm this by checking the mast's diameter and whether it has a guy wire or brace. A thin, unsupported mast on a roof that dumps a lot of snow is a setup for repeat problems.
• Tree limbs overhanging the service drop. If a tree branch loaded with ice sagged onto the wire or snapped onto the mast, the damage can look identical to a roof-snow strike. Walk the path of the line from the utility pole to your house and look for broken or drooping branches near or touching the wire.
• Ice damming at the roof penetration. Sometimes the mast itself is fine, but ice damming at the eave has backed water up under the flashing where the mast passes through the roof. This shows up as water stains on the ceiling or soffit near the mast rather than visible bending of the metal. It's a roofing and flashing problem more than an electrical one, though it can still lead to water getting into the mast or meter base over time.

How to fix it

Service entrance work involves live, high-amperage wires from the utility, so this isn't a DIY repair. Here's the general order of operations:

• Don't touch it. If the mast is visibly bent, the wire is down, or the meter is hanging loose, stay away and keep others away too. A downed or compromised service line can be energized even if nothing looks obviously dangerous.
• Call your utility first if the drop wire itself (the wire from the pole to your house) is down or damaged. That wire belongs to the utility, and they need to de-energize it before anyone touches the mast or meter.
• Get a licensed electrician to inspect the mast, weatherhead, conduit, and meter base. They'll check for cracked conduit, water intrusion, loose lugs at the meter, and whether the mast is still structurally sound or needs replacement.
• Replace the bent or cracked mast and reseal the weatherhead. This usually means a new piece of rigid conduit, a new weatherhead fitting, and proper flashing and sealant where it passes through the roof. The drip loop (the little dip in the wire below the weatherhead) needs to be re-formed correctly so water runs off the wire instead of into the fitting.
• Add bracing if the mast is undersized for the load. This can mean a heavier gauge mast, a guy wire anchored to the roof structure, or in some cases relocating the point of attachment to a spot on the house that doesn't sit directly under a snow-shedding roof plane.
• Trim back any tree limbs that could reach the drop wire again next winter.

Costs vary a lot depending on whether it's a simple mast and weatherhead swap or a full service relocation, and whether the utility needs to schedule a disconnect and reconnect. As a rough range, a straightforward mast repair often runs in the low hundreds to around a thousand dollars, while a full service entrance relocation or upgrade can run several thousand. Get an actual quote for your situation rather than relying on this as a bid.

When it is not worth fixing

If the damage is limited to the mast and weatherhead and the rest of the service entrance (panel, wiring, grounding) is in decent shape, repairing just the damaged section makes sense. But there are a few situations where a patch repair isn't the smart move.

If your home still has an older fuse panel, aluminum branch wiring, or a service rated below 100 amps, a snow-related mast failure is often a good trigger to do a full service upgrade instead of just fixing the broken piece. You're already paying for an electrician, a utility disconnect, and possibly a permit inspection, so doing the whole job at once usually costs less than doing it twice.

If the same spot keeps getting hit year after year because of how the roof sheds snow, repeated mast repairs are just throwing money at a design problem. In that case, relocating the service entrance to a wall that doesn't sit under a steep snow-shedding roof plane is the more honest fix, even though it costs more upfront.

And if the mast damage is minor (a small bend, cosmetic scrape) but everything else tests out fine, sometimes the right answer is simply to monitor it and address it at your next scheduled roof or siding work rather than treating it as an emergency.

Sageland Electric handles service entrance repairs and upgrades across Bonner and Kootenai counties, including the kind of mast and weatherhead damage that shows up after a heavy snow year. If you're not sure whether what you're looking at is cosmetic or serious, it's worth having someone take a look before the next storm adds more weight to it.