Volcanic eruption coverage: ash, lava and what your policy pays

A standard homeowners policy covers damage from a volcanic eruption: ash, lava, ballistic rock and the fires they start. It does not cover the ground shaking and land shock waves that accompany an eruption, and it excludes mudflows and landslides, including the volcanic mudflows called lahars. The gap that matters for most owners is not the policy wording. It is whether anyone will sell the policy in a high-hazard lava zone, which in parts of Hawaii has become a real problem.

What the HO-3 says about eruptions

The ISO HO-3 (form HO 00 03 05 11, the 2011 edition hosted by the Maine Bureau of Insurance) treats volcanic eruption in four places.

• Dwelling and other structures (Coverages A and B). These are open perils coverages: the policy pays for direct physical loss unless an exclusion applies, and volcanic eruption is not on the exclusion list. Ash that crushes a roof, lava that burns a house and a rock thrown through a window are all direct physical loss.
• Personal property (Coverage C). This is a named perils coverage, and "Volcanic Eruption" is peril 16 of 16. The peril "does not include loss caused by earthquake, land shock waves or tremors."
• Ash removal. Under Additional Coverages, Debris Removal pays your reasonable expense to remove "ash, dust or particles from a volcanic eruption that has caused direct loss to a building or property contained in a building." That expense counts against the limit for the damaged property, with the form's extra 5% available when the loss uses up the limit. See debris removal and tree removal coverage.
• The 72-hour rule. Section I Conditions say that "one or more volcanic eruptions that occur within a 72-hour period will be considered as one volcanic eruption." In practice, that is how the policy decides how many occurrences, and so how many deductibles, a long eruption produces.

Policy language varies by insurer and state. Many insurers use their own forms, and some have lava or volcanic wording that the ISO form does not. Read the exclusions section of your policy and the declarations page, and ask your agent whether anything in an amendatory endorsement touches eruption.

What is excluded

The exclusions that matter all sit in the earth movement group, covered in the earth movement exclusion explained:

• Earthquake and land shock waves. The exclusion lists "land shock waves or tremors before, during or after a volcanic eruption." A cracked foundation from eruption-related tremors is a denial, whatever the volcano did. Earthquake insurance is a separate purchase (earthquake insurance explained), and its wording on volcano-related shaking varies.
• Landslide, mudslide and mudflow. Eruptions melt snow and ice and shake loose volcanic debris, which can produce a lahar. The HO-3 excludes mudflow. Flood insurance has its own narrow mudflow definition, which landslides and mudflow: what's covered covers.
• Subsidence and sinkholes. Ground that sinks near a volcanic field falls in the same "earth sinking, rising or shifting" bucket.
• Vehicles. Ash that pits paint and clogs engines is an auto policy question. A homeowners policy excludes motor vehicles from Coverage C, and the coverage for ash on a car is the comprehensive coverage on the auto policy.
• Condo loss assessments. The HO-3 and HO-6 loss assessment coverage, which has a $1,000 limit in the ISO forms, does not apply to assessments caused by earthquake or volcanic land shock waves.

Ash: the damage and how claims go

Ash is not smoke. It is pulverized rock and glass, abrasive and heavy. According to the U.S. Geological Survey, roof collapse generally takes deposits deeper than about 100 millimeters (4 inches), and thinner falls tend to damage gutters and overhangs rather than structure. Wet ash can weigh up to twice as much as dry ash, so a rainfall on a deposit makes the load worse. Ash also clogs filters and air intakes, which can knock out heating, ventilation and air conditioning, and it can corrode thin or aged metal roofing.

That produces a typical claim file: a collapsed or sagging section of roof, a failed air conditioner or heat pump, interior contamination where ash came in through vents, and the cost of cleaning or removing the ash. Three practical points:

1. The USGS says to shut down heat pumps and air conditioning units that draw outdoor air and keep doors and windows closed during ashfall. That also limits the damage you will later have to claim, and the policy's duty to protect the property from further loss applies (reasonable repairs: what you can fix before the adjuster comes).
2. Be careful on the roof. The USGS notes that ash makes roof surfaces slippery and that roof clearing has caused many injuries and some deaths from falls and collapses. A roofer's invoice for emergency clearing is a better expense to claim than a fall is to recover from.
3. Keep the debris removal clause in view. It is tied to ash that has caused direct loss to a building or its contents. Ask the adjuster in writing how the claim treats ash on the ground around the house.

A hypothetical example. Say an eruption drops ash over 40 hours and a second pulse follows 30 hours after that. Under the 72-hour rule, the policy reads those as one eruption, so one deductible applies. If the second pulse had come five days later, it would be a separate eruption and could carry its own deductible. Whether your policy applies a flat or percentage deductible to this peril is on the declarations page.

Lava: the Hawaii experience

Lava is rarer than ash and harder to insure. The USGS says the 2018 Kīlauea lower East Rift Zone eruption, which ran from May 3 to September 5 of that year, destroyed 723 structures. In May 2018, Hawaii Insurance Commissioner Gordon Ito told reporters that homes destroyed or damaged by the lava were covered under homeowners policies and treated as fire losses, adding that his office had received no policyholder complaints about claims and that the same approach was used when lava took a few homes near Pahoa in 2014 (Claims Journal, May 11, 2018).

That is a statement about the policies of the time and the way they were adjusted, not a guarantee. The point to take from it is that lava damage is generally a fire-type loss under the standard form, and that the coverage question for a Hawaii owner is the form, not a separate "lava" peril. Check yours.

Finding coverage in a lava zone

The USGS divides the Island of Hawaii into nine lava flow hazard zones. A USGS scientist told a public meeting in August 2023 that the 1992 map is "a lava flow hazard map, not a risk map," and that the agency does not calculate risk (Hawaii Tribune-Herald, Aug. 27, 2023). Insurers use the zones anyway. The same article reported residents in zones 1 and 2 describing premium increases of 300% to 400% or more, and the exit of Universal Property & Casualty (Universal Property & Casualty) from Hawaii homeowners, condo and renters business, which affected about 1,500 policyholders statewide, according to the report.

The market of last resort is the Hawaii Property Insurance Association. According to its FAQ, HPIA writes basic residential property insurance, with limits from $50,000 to $450,000 and deductible options of $500, $1,000, $2,000 or $3,000. An applicant must first try the voluntary market, and HPIA accepts applications only after at least two declinations from licensed insurers. HPIA describes itself as a market of last resort, with generally higher premiums and less coverage than voluntary policies, and its FAQ does not state how it treats lava, so ask the plan administrator for the actual form. General background on plans like it is in FAIR plans explained: the insurer of last resort for homes; the broader problem of finding a home insurer is in finding coverage for a hard-to-insure home and the Hawaii state guide.

Where eruptions are a risk. The USGS's 2018 update of its national volcanic threat assessment counts 161 potentially active U.S. volcanoes, 18 of them in the "very high threat" tier: five in Alaska, two in Hawaii (Kīlauea and Mauna Loa) and eleven in Washington, Oregon and California. It is a ranking of threat for monitoring priorities, not a forecast of the next eruption. Most owners in those states face ash and mudflow risk, not lava.

Before an eruption: a short checklist

1. Read the three places that matter: the Coverage C named perils list, the earth movement exclusion and the debris removal clause. Look for any lava, volcanic or earth movement endorsement.
2. Photograph the roof, the HVAC intakes and the contents, and keep a how to make a home inventory for insurance copy off site.
3. Confirm what you do not have. Earthquake coverage, flood coverage and an auto comprehensive policy each fill a gap the homeowners policy leaves. The homeowners coverage gap checker lists them.
4. In a lava zone, ask in writing whether the policy excludes lava, who the insurer is and whether it has stopped renewing in your zone.

Key takeaways

• The ISO HO-3 pays for eruption damage to the dwelling under its open-perils coverage and to belongings under a named "Volcanic Eruption" peril, and it pays to remove ash that has damaged a building.
• Earthquake, land shock waves, landslide and mudflow tied to an eruption are excluded; separate earthquake and flood policies fill part of that gap.
• Eruptions within 72 hours count as one eruption, which sets how many deductibles apply.
• Hawaii's insurance commissioner said in 2018 that lava damage was being paid as fire loss, but owners in the highest-hazard zones now face scarce and costly coverage, with HPIA as the last resort.
• Check your own policy and declarations page: insurers' forms vary from the ISO text.