Tree Subsidence Report.
Evidence Before Assumption.

A tree subsidence report is an arboricultural assessment used where vegetation is suspected of causing or contributing to structural movement. It considers the trees in context with the available building, soil, foundation, monitoring, drainage and root evidence rather than assuming that the nearest tree is responsible.

Tree-related subsidence can occur where vegetation removes moisture from shrinkable cohesive soil, causing the ground to reduce in volume and foundations to move. Trees are only one possible cause of subsidence, so the mechanism should be supported by appropriate evidence.

Yes, in some circumstances. The risk is particularly associated with shrinkable clay soils, moisture-demanding vegetation and foundations that are affected by seasonal soil-volume change. Not every tree close to a building is causing damage.

Potentially. Large shrubs, hedges and groups of woody vegetation can also remove soil moisture. Their relevance depends on species, size, density, soil conditions, distance and the affected structure.

Subsidence is downward movement of the ground supporting a building. Settlement is normally associated with the building or made ground adjusting under load, particularly earlier in a building's life. Distinguishing causes is a structural question and may require an engineer or surveyor.

Heave is upward ground movement associated with soil expansion. On some shrinkable clay sites, removing established vegetation can allow soil to rehydrate and swell, so felling is not automatically a risk-free solution.

Direct damage is physical damage caused by tree growth or contact, such as displacement of paving, walls or lightweight structures. It is different from indirect subsidence damage caused by soil-volume change.

Indirect damage occurs through changes in the supporting ground rather than physical root pressure. In tree-related subsidence cases, the concern is usually moisture extraction from shrinkable soil and resulting foundation movement.

No. Cracking can have many causes. A robust subsidence investigation should consider the crack pattern, movement data, foundations, soil, drainage, vegetation and other plausible causes.

For an insured home with suspected subsidence, contacting the buildings insurer early is usually sensible because the insurer may appoint engineers, surveyors, loss adjusters and investigation contractors. The ABI also advises policyholders to contact their insurer when subsidence is suspected.

The arboricultural consultant assesses the relevant trees and vegetation, interprets their species characteristics, size, vitality, water demand, distance and management history, and relates those findings to the wider technical evidence.

The structural engineer or building professional assesses the building movement, structural significance, foundation condition and repair implications. Arboricultural evidence complements rather than replaces that work.

The required evidence depends on the case, but robust investigations commonly include building damage information, monitoring, foundation details, soil analysis, root identification, drainage evidence, a vegetation plan and an arboricultural report.

Level monitoring can show the extent, direction and timing of movement. Seasonal patterns may be relevant to a vegetation-related hypothesis, while inconsistent movement can point towards other mechanisms.

Crack monitoring helps record whether cracks are stable, opening, closing or changing seasonally. It is one part of the evidence and should be interpreted alongside other investigations.

There is no single period that fits every claim. Some local-authority evidence requirements refer to extended or seasonal monitoring, and insurers or engineers may set the programme according to the specific case.

A trial pit or borehole can provide foundation depth, foundation type, soil profile and locations for sampling or root observations. This helps relate the vegetation to the actual ground supporting the affected structure.

Plasticity describes how fine-grained soils behave as their moisture content changes. Liquid limit, plastic limit and plasticity index can help engineers classify shrinkable clay and its potential for volume change.

Soil moisture deficit describes a reduction in soil moisture relative to an expected state. In a subsidence investigation it can help the wider technical team assess desiccation, but it should not be interpreted in isolation.

Species influences expected mature size, rooting behaviour, water-demand characteristics and response to pruning or removal. Those characteristics help the arboricultural consultant assess plausibility.

A vigorous tree may have different current and future water demand from a declining tree. Vitality is therefore one factor in the overall assessment rather than a stand-alone proof of causation.

Distance helps place the tree in context with its size, species and the affected foundations. A nearby tree may be relevant, but distance alone does not establish causation.

Potentially, depending on species, size, soil conditions, foundation depth and site context. That is why a proper assessment should consider the wider vegetation pattern rather than only the nearest trunk.

Yes. Trees on neighbouring or public land can be relevant if the evidence indicates they may contribute to the damage. Ownership affects permissions and liability, but not the physical assessment.

Yes. Claims involving council trees normally require a structured evidence package and are handled through the authority's insurance or claims process. Requirements vary between councils.

Finding roots near a foundation does not prove which tree they came from. Identification can help link roots to species or individual trees and should be interpreted with the rest of the evidence.

Where root identity is important and conventional identification is inconclusive, more specialist laboratory techniques such as DNA analysis may be considered. The need should be proportionate to the claim.

Where appropriate and safely scoped, air excavation can expose roots or soil around sensitive areas with less mechanical disturbance than conventional digging. It is a diagnostic tool, not automatic proof of subsidence causation.

Drainage defects can contribute to ground movement or foundation problems and should be investigated where relevant. A tree should not be blamed simply because it is close to the property.

The classic vegetation-related shrinkage mechanism is most associated with shrinkable cohesive soils. Other soils can have different movement mechanisms, including erosion or washout, so the wider ground investigation matters.

London Clay is a geological formation containing shrinkable clay that is widespread in parts of London and the South East. Its presence can be relevant to foundation movement, but site-specific soil evidence is still important.

Prolonged dry periods can increase moisture loss from shrinkable soils. The ABI identifies both dry weather and trees or shrubs as potential contributors to subsidence, particularly where clay soils are present.

Pruning can reduce foliage temporarily, but its effect on long-term soil moisture and structural movement depends on species, pruning cycle, tree response and the evidence in the case. It should not be presented as a universal cure.

Removal may be recommended in some evidence-led cases, but it is not automatically appropriate. The investigation should consider whether the tree is materially involved, statutory protection, alternative options and potential heave risk.

Where a long-established tree has dried shrinkable soil, removal can allow rehydration and expansion. The significance depends on the soil, vegetation history, foundations and engineering evidence.

Root barriers can be technically complex and are not suitable for every site. Their feasibility, depth, continuity, engineering effects and impact on tree stability should be evaluated by the appropriate specialists.

Underpinning is a structural remedy and sits outside the arboricultural consultant's decision-making role. An engineer may consider it where other measures are not suitable or where structural stabilisation is required.

Protected status does not make justified work impossible, but applications alleging subsidence should be supported by appropriate technical evidence. Government guidance requires evidence that the tree is a material cause and that other influences have been eliminated so far as possible.

Government and local-authority guidance commonly refers to property damage information, movement monitoring, trial pits or boreholes, soil characteristics, root location and identification, vegetation information and consideration of repair or management options.

Where instructed, Arbor Cultural can provide the arboricultural evidence and tree assessment needed to support the wider application. Structural, soil, monitoring and other evidence may still need to come from the relevant specialists.

Yes. Tree work in a Conservation Area can be subject to statutory notice requirements, and TPO controls may also apply. The correct planning route should be checked before works are carried out.

Arbor Cultural can review relevant soil information as part of the arboricultural interpretation, but specialist geotechnical analysis and laboratory testing remain the responsibility of the appropriate soil or engineering professionals.

Yes, where provided and within the agreed instruction. The arboricultural report can interpret the tree evidence alongside the wider technical material without replacing the engineer's structural conclusions.

Arbor Cultural's existing service information includes Arborcheck vitality testing. Where it is genuinely relevant to a complex case, vitality information may help describe the physiological condition of the tree.

Fees depend on the number of relevant trees, location, complexity of the evidence, whether a TPO application is involved, whether specialist diagnostic work is required and how much technical material must be reviewed. Arbor Cultural provides a fixed-fee proposal for the agreed arboricultural scope.

Timescales depend on site access, the available technical evidence and whether the case is at an early investigation stage or already has monitoring, soil and root data. Some claims cannot be concluded responsibly until sufficient evidence has been gathered.

Send the property address, insurer or loss-adjuster correspondence, structural engineer or surveyor reports, crack or level monitoring, trial-pit or borehole information, soil analysis, drainage reports, root-identification results, photographs and details of relevant trees if available.

No. The report provides an independent arboricultural opinion based on the evidence available. Insurers, engineers, loss adjusters, tree owners and Local Planning Authorities make their own decisions within their respective roles.