Dangerous tree in France: warning signs, tree health assessment and who is liable

A tree is not dangerous because it is tall, old or leaning. It becomes dangerous when two conditions meet: a defect that makes the failure of a branch, the trunk or the root plate likely, and a target within falling distance. A hollow oak at the far end of a meadow threatens nobody; the same oak over a bedroom, a gate or a departmental road does.

• The signs that matter can be read from the ground by walking around the tree: at the base, on the trunk, at the forks, then in the crown. Most are described below, with how urgently each should be dealt with.
• Under French law the owner answers for damage caused by their tree, even without fault. Only a truly exceptional storm, on a healthy and maintained tree, can release them.
• Felling a dangerous tree is exempt from some formalities, but not all, and never from proof: photographs and a written opinion are gathered before the cut, not after.
• Felling is not the only answer. Removing deadwood, lightening a limb or bracing a fork is often enough to bring the risk back to an acceptable level.

The pages that rank first on this subject in France are almost all written by insurers. They explain very well who pays after the fall. They say little about what can be seen beforehand, and that is where everything is decided: a tree nearly always gives warning. This article therefore starts with the tree, and only then turns to the law and to insurance.

You inspect a tree the way you read a page: in order. First the soil and the base, because that is where the fall of the whole tree is decided. Then the trunk, then the forks and main limbs, and finally the foliage. Two inspections a year are enough: one in winter, when the framework is bare, one in summer, when the foliage shows the vigour. And a third after every serious blow.

At the base: the anchorage

• A new or increasing lean. A tree that grew leaning built itself to lean; a straight tree that starts to lean is letting go.
• Soil cracking or lifting in an arc on the side opposite the lean: the root plate is tipping. This is the most urgent sign on the whole list.
• Bracket or clustered fungi at the root collar and on surface roots. They are only the visible part of a decay that has been working through the wood for years.
• Roots cut by a trench, earthworks, a utility line or a fence. The tree does not react straight away: failure often comes two to five years later.
• Recent backfill or paving against the trunk: a buried root collar suffocates and rots with nothing to show for it.

On the trunk and at the forks: the structure

• An open vertical crack, especially one that runs through the trunk or starts at a fork.
• A tight V-shaped fork where the bark of the two stems has closed between them instead of the wood fusing. This “included bark” is the most common failure point on multi-stemmed trees.
• An open cavity, a dark bleed, bark coming away in plates or sounding hollow when struck with the flat of the hand.
• Large old pruning wounds that never closed, particularly on a topped tree: the regrowth around them is poorly attached to wood that is rotting.

In the crown: the vigour

• Large-diameter deadwood above somewhere people walk. A dry branch as thick as an arm drops with no wind and no noise.
• A crown thinning from the top down, which arborists call dieback: the tree is giving up its extremities for lack of water or roots.
• Sparse, small foliage, yellowing before its season, on one side or on a single limb.
• A broken branch left hanging in the canopy after a gale: it will come down eventually.

We are called at least as often for a tree that frightens as for a tree that deserves it. Many fellings requested “for safety” remove sound trees, while the pine that really was unstable stayed straight and green until the day it fell. Before condemning a tree, rule out what is not a defect.

• The tree that has always leaned. Year after year it has laid down reaction wood to compensate. The danger comes from change, not from the angle.
• The hollow tree. A trunk is a tube: it stands on its outer wall. An old tree that is largely hollow, with a thick sound wall, often holds up better than you would think. What decides is the thickness of sound wood remaining, and that can be measured.
• Height. A tall, balanced, well-anchored tree is no more dangerous than a small one. Cutting it in half “so it cannot reach the house” creates exactly the defect you wanted to avoid.
• Moss and lichen. They live on the bark, not in the wood, and say nothing about the strength of the tree.
• Ivy. It does not strangle a vigorous tree. Its real fault is hiding the trunk and forks from inspection, and adding wind load to a tree that is already weak: you sever it at the base in order to see, not on principle.
• Small deadwood inside the crown. A tree naturally sheds twigs that no longer get light. What matters is the diameter, and what is underneath.

Conversely, be wary of reassuring trees. A poplar or a pine that looks in perfect health, whose roots were cut when a garage was built, shows nothing for years. The history of the plot tells you as much as the look of the tree: building work, a change in ground level, irrigation switched off, a neighbouring tree felled that used to shelter it from the wind.

There are three levels of opinion, and they are not equivalent. Confusing them is the main source of disappointment: people expect a pruning quote to carry the weight of an expert report, or pay for an expert report on a dead branch any professional would have spotted.

From the mallet to the tomograph: the assessment tools

The basic method is a visual inspection of the whole tree, defect by defect, usually known by its initials VTA (visual tree assessment). It is completed by sounding with a mallet: sound wood rings full, hollow or decayed wood sounds dull. In the great majority of cases, the eye and the mallet are enough to conclude.

• The resistograph: a very fine needle drills into the wood and records the resistance it meets. The trace shows where the wood is sound, where it is altered, and how thick the remaining wall is.
• Sonic tomography: sensors placed around the trunk measure the speed of a sound wave through the wood and draw a cross-section of the trunk, cavities included.
• The pulling test: the tree is pulled with a measured force and the reaction of the trunk and root plate is recorded. It is the only way to judge an anchorage you cannot see.

An assessment describes the tree on a given date. A summer of drought, a trench or a gale can make it obsolete: serious reports state a validity period and a date for the next check. Keep it, with your maintenance invoices: it is your best defence if the tree ever causes damage.

A professional who proposes felling without having walked around the tree has not assessed it, he has sold it. The checks to make before signing are here: How to choose a tree surgeon in France: 12 checks.

French law does not ask the victim to prove that you neglected your tree. Article 1242 of the Civil Code makes everyone liable for damage caused by the things in their keeping, and a tree is one of them. If yours falls on the neighbour’s fence, car or roof, you are presumed liable simply because the tree is yours.

There is only one way out: force majeure, meaning an unforeseeable and irresistible event. The courts accept it sparingly. A wind that is usual for the region does not qualify, and a storm does not release the owner of a tree known to be diseased, dead or reported as dangerous. In other words, the wind only excuses a healthy, maintained tree.

On top of that comes liability for fault under articles 1240 and 1241: someone who was warned of the danger, by a letter from the neighbour, by the mairie or by a professional, and did nothing, has been negligent. That is what makes written records so important, in both directions: the neighbour’s letter binds you, the accepted quote and the pruning invoice protect you.

Tenant, landlord, co-ownership: who does what

• The tenant handles routine upkeep of the garden they rent, including trimming and pruning the trees: it is a tenant’s repair, listed in the decree of 26 August 1987.
• The landlord remains responsible for whatever goes beyond upkeep: felling a dead, diseased or dangerous tree falls to them. A tenant who notices a danger must report it in writing, and cuts nothing on their own initiative.
• In a co-ownership (copropriété), a tree in a common area is the responsibility of the owners’ association, through the managing agent (syndic), even if it stands in a garden reserved for one owner’s exclusive use. The co-ownership rules set out who maintains what.
• A tree planted in a shared boundary hedge is shared like the hedge: both neighbours share its upkeep, the decision and the liability.

You may not enter the neighbour’s land, cut their tree or have it felled in their place. The Civil Code lets you require them to cut branches that overhang your land, and lets you cut, at the boundary, roots that cross it yourself; it never allows you to touch the trunk. You do, however, have the means to make them act, provided you proceed in order.

1. 1Talk to them, with the tree in front of you. Most owners do not know the state of their tree, especially when the defect is visible from your side and not from theirs.
2. 2Write. An ordinary dated letter with photographs, describing what you see and what you fear. Keep a copy.
3. 3Send formal notice (mise en demeure) by registered letter with acknowledgement of receipt, setting a precise and reasonable deadline. Without a deadline, it is not formal notice. This letter proves the owner knew of the danger.
4. 4Have it recorded. A written opinion from a professional or, better, a report by a commissaire de justice (the former huissier) carries a weight your own photographs do not.
5. 5Refer the matter to the conciliateur de justice, free of charge, at the mairie or online. For a neighbour dispute, this amicable attempt is in principle compulsory before any court action.
6. 6As a last resort, or straight away if the danger is imminent, go to the tribunal judiciaire. The urgent-applications judge (juge des référés) can order measures to prevent imminent damage, and manifest urgency waives the prior conciliation.

When the mairie can step in

The mayor does not referee quarrels between neighbours, but is responsible for public safety. If the tree threatens a street, a pavement, a lane or a school, report it to the mairie in writing. The mayor can serve notice on the owner to cut back whatever encroaches on the road and, if they fail to comply, have the work carried out at the owner’s expense. Where the danger is serious or imminent, the local-government code (Code général des collectivités territoriales) allows the mayor to order the necessary safety measures without delay, up to closing a road.

Planting distances, the thirty-year limitation rule and what happens to overhanging branches and roots are covered in a separate article: Neighbour’s tree or hedge on the boundary: distances, branches, roots.

French home insurance works through two different covers, and the nasty surprises come from confusing them. Civil liability (responsabilité civile) covers the damage your tree does to others. Storm cover (garantie tempête), which by law comes with any policy covering fire, covers the damage the wind does to your own buildings, including through a falling tree.

The time limit for reporting a claim is as a general rule five working days from the day you become aware of it. If a natural-disaster order (arrêté de catastrophe naturelle) is published, the limit is thirty days after its publication. Photograph everything before clearing, have only the essential protective work done, and keep the invoices.

In a garden with no particular protection, no: you are free to fell a tree that belongs to you. The question only arises if the tree or the land is protected, and the answer then depends on the protection.

• Classified woodland (espace boisé classé) or a tree identified in the local plan (PLU): felling normally requires a prior declaration, but the planning code exempts the removal of dangerous trees, windblown trees and deadwood (article R. 421-23-2 of the Code de l’urbanisme).
• Surroundings of a historic monument, a heritage site, a listed or classified site: the exemption does not work the same way. Contact the mairie before any cut, even in an emergency.
• A row or avenue of trees along a road open to public traffic: felling is prohibited in principle, whoever owns the trees. It becomes possible again if the health or mechanical condition of the tree is a danger, subject to a declaration to the prefect.
• Housing estates (lotissements) and co-ownerships: the rules or the estate charter may require trees to be kept or replaced.

In every case, the exemption only holds if the danger can be demonstrated afterwards. A stump proves nothing. Before felling: dated photographs of the defect, the base and the target; a written opinion from the professional; and an email to the mairie to inform them, which costs nothing and shuts the door on any challenge.

That leaves wildlife. Destroying occupied nests and protected species is prohibited all year round, and an old tree with cavities often shelters birds or bats. Unless the danger is immediate, felling is scheduled outside the nesting season, which runs from mid-March to the end of July.

Each type of protection, how to check it at the mairie and the prior-declaration form are explained step by step in our guide: Felling a tree in France: do you need permission?.

An assessment does not lead automatically to the chainsaw. You act on one of the two terms of the danger: the defect, or the target. Moving a bench, a play area or a parking space sometimes settles the matter without touching the tree. When the target is a house, four families of work remain.

A word on topping, which we are still asked for “to make the tree less dangerous”. Cutting the head off a mature tree opens large wounds that do not close, through which decay enters, and triggers long, heavy, poorly attached regrowth. A topped tree is shorter for three years, and more dangerous for thirty.

Deadwood removal, lightening, safety pruning: the methods and what a quote contains are described on the service page: Tree pruning in Lapalud and Bollène.

When the tree cannot be kept, the dismantling, and what happens to the wood and the stump, are decided before the job: Tree felling and stump removal in Lapalud.

Felling a dangerous tree does not qualify for the 50% tax credit. The scheme in detail and the other levers worth checking are here: Tax credit for tree pruning and felling in France: what qualifies.

A guide written for the whole of France does not tell you what breaks in the Rhône corridor. Between Orange, Bollène, Pierrelatte and Pont-Saint-Esprit, danger has four well-identified faces, and none of them looks like those of a garden in Brittany or in Kent.

The mistral: an ordinary wind, so not an excuse

The mistral blows from the north, in spells of several days, with gusts that can exceed 100 km/h in the valley. It always loads trees in the same direction, and it finds the cracked branch or the weak fork long before anything else. Two consequences. First, an inspection is called for after every marked spell. Second, a wind this usual here will be hard to present as unforeseeable: the force majeure argument weighs less in Lapalud than elsewhere.

The Aleppo pine: standing until the last day

On the thin limestone soils of the hills, around Uchaux, Mondragon or the Ardèche plateau, the Aleppo pine roots near the surface. Heavy in the crown and evergreen, it goes over in one piece when the soil is soaked by an autumn downpour and the wind gets up behind it. Its branches also snap under heavy wet snow, rare but formidable. No foliage gives warning: only the base, the cracked soil and the lean speak.

The plane tree and canker stain

Vaucluse is one of the French departments worst affected by canker stain (chancre coloré), a fungus that kills a plane tree within a few years and that no treatment can stop. A plane tree with a main limb drying out in midsummer, and bark turning purplish brown in flame-shaped streaks along the trunk, must be reported: control is compulsory and overseen by the State, and felling then follows a strict protocol. You do not prune or fell a suspect plane tree yourself: tools and sawdust carry the disease to the next tree.

Cypresses, poplars and oaks: the aftermath of drought

Cypress hedges turn rust-brown in patches because of a bark canker, and the dead trees, dry and resinous, become both brittle and flammable. In the alluvial plain of the Rhône, poplars, with their soft wood and fast growth, drop large limbs without warning. As for oaks, several dry summers in a row show in the crown, which thins out: an oak in dieback over a courtyard deserves an opinion before winter.

A dead tree near a house is also fuel. In communes subject to the legal brush-clearance obligation, removing it is part of the work required: Mandatory brush clearance in France: the 50 metres and the penalties.

1. 1Move everyone out of the fall zone, which is at least the height of the tree, and close it off: car moved, room under the tree emptied, path blocked.
2. 2If the tree threatens a road or is touching a power line, call the fire service on 18 or 112. Never go near a tree in contact with a cable: the network operator must intervene first.
3. 3Tell the mairie if the public highway is affected, and the neighbour if their property is in the zone.
4. 4Photograph the tree, the base, the defect and what it threatens, without standing underneath.
5. 5Call a professional to make it safe. Do not climb the tree, do not cut a branch under tension and do not try to hold the trunk back with a strap: that is how serious accidents happen.
6. 6Tell your insurer, then keep the quote, the invoice and the photographs.

An emergency job costs more and leaves fewer options than a planned one: nothing is preserved, it is simply cleared. That is the whole point of regular inspection. If you have a doubt about a tree in our area, send us photographs of the base, the trunk and the crown with your request: they make it possible to say, even before the visit, whether we need to come quickly.