Tom has recently successfully completed the Consulting Arborist Society (CAS) Tree Report for Mortgage that was run through Lantra, the land-based training provider, see Mortgage and Insurance Course on the CAS website. This is the only cross industry-recognised qualification and means that Arbor Cultural Ltd is right up to date with the current requirements of a tree report for mortgage or insurance purposes. He also gained a CAS competency in the subject in the process.
Direct and Indirect Damage
Direct damage is when roots or branches come into direct contact with foundations, walls or roofs. This is often addressed by simply pruning the offending part, taking it back far enough so as to reduce the risk of it occurring again. This may result in a cyclical management regime.
Indirect damage is when roots are below the level of the foundations and are taking water out of the soil. This will only be an issue in shrinkable clay soils. The clay particles are very small and the removal of the water results in the soil contracting and the soil level reducing. This occurs in periods of drought conditions.
This movement occurs all the time in shrinkable soils but is normally evenly spread across the property. It is only when trees or vegetation affect one section of a building’s foundations to a greater extent than the others that it becomes a problem, resulting in damage to the building.
If this level reduction is significant enough then the building or part of the building over the affected area may drop resulting in cracks and in extreme conditions partial wall failures. This damage is called subsidence.
Other Causes of Movement in Buildings
Other causes are of building movement are settlement under load, underground water movement or leaking drains washing particles away, collapsing mines and poor construction techniques. All of these can occur at any time of the year.
For the damage to be tree or vegetation related the movement must be seasonal, so part of the building dropping in prolonged periods of drought, only to rise again in the wetter months of the year as the soil rehydrates. Tis can be determines by crack or level monitoring over time.
As the tree or trees grow this will result in an increasing persistent water deficit and the increase in the amount and degree of damage over time.
If caught early enough then this can be addressed with simply tree management strategies. If left too late then it may become necessary to resort to underpinning of the foundations under part or all the building.
Heave
If a tree or trees are removed or reduced to far back, then it may cause heave. This is the opposite of subsidence and is when the soil swells to a volume greater than when the structure was built, lifting it above the construction level and potentially causing damage and cracking. For this to occur the building would have to be significantly older than the property.
This can cause as much damage as subsidence, which is why tree reports for mortgages should only be undertaken by experienced professionally with suitable qualifications and experience. Why would you trust you house to anyone else?
This is something that we at Arbor Cultural Ltd. can undertake for you.
Aspects to Consider in a Tree Report
The main elements to consider are the trees species, vitality, growth potential, water demand, distance to the buildings, land topography and previous tree management.
The tree species is closely linked to the water demand, with oaks, willows and poplars having a much higher potential water demand so being more likely to impact on buildings.
Comparisons are made with historic data records of tree damage by species.
Soil is assessed using on-line soil resources and additional reports, along with soil sampling and texturing on site if appropriate.
The main way to address any significant concerns is with specific tree management of the minimal extent to address and insurance or mortgage concerns. We do not provide tree surgery services ourselves and do not make unnecessary recommendations or generate unnecessary tree work.
Tree surgery can be very expensive and once started will normally require regular repeated management. Also trees and mature landscapes increase property values, so why would you want to impact that unless it was absolutely necessary.
We provide tree reports for mortgage and insurance purposes.