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Soil and Water Sample Surveys in Canterbury
Subsidence reports must consider current site conditions and any potential liabilities that could stem from the subsidence. Environmental concerns, such as pollution of the soil and water, may be present. A thorough site investigation could be performed. It would consist of the recovery of soil, root, and water samples, which then could be analysed in the laboratory.
The organisation of specialist or contamination tests can be done, and these range from the testing of simple moisture content and classification to effective stress and shear testing that complies with BS 1377. Your surveyor or engineer can contract out the tests to a select group of laboratories that are accredited by NAMAS. These laboratories have a long-standing working relationship with your surveyor or engineer and a strong record of providing reliable results.
Insurance Claims Related to Subsidence
When so many subsidence issues arise, our panel of CIOB, RPSA and/or RICS surveyors is routinely called upon to unfurl their innumerable layers of technical and engineering riddles.
This is a service we perform when we advise insurers, insurers’ appointed loss adjusters, and the insured with respect to the plethora of ways in which buildings can be damaged—subsidence being just one. When anything that requires an insurance claim arises from a subsidence issue, our surveying organisation steps in to assist with our structural engineering expertise.
Your surveyor needs to keep in very close contact with all the important people at all the important times. This is especially true when it’s a matter of agreeing with you as to how and in what direction to proceed when further investigation or additional—and sometimes quite extensive—work is necessary. If your house is subsiding, unless something very particular (and rare) happens, your insurance policy will pay for the investigation and any necessary remedial work. The same is generally true for any policy that covers your house against a range of perils.
Subsidence & Remedial Measures: What You Need to Know
All buildings and structures move to some extent, but most do so in ways that are harmless.
Damage is often found in cracked walls and ceilings. The windows/doors may have also shifted and are unable to open/close. These are among the most pronounced signs of ground or foundational movement. But how do you know if what you’ve got going on with your house is the kind of problem that needs urgent attention?
What is a Subsidence Report?
Your subsidence report comprises the subsequent elements:
- suspected causes of the problem
- a brief but detailed description of the style and methodology of the property’s construction
- extent of damage and the manner in which the property is responding to the forces of nature
- potential “real” root causes of subsidence and subsidence-like behavior
- relevance to insurance claims
- authorities’ approvals (like building control or party wall, etc.
- the all-important summary with the essential recommendations
Chartered Surveyor Subsidence Inspection & Monitoring in Canterbury
Monitoring and inspecting subsidence require the skills of specialised surveyors. For one, it is crucial to determine and monitor any movement occurring in the building itself—an endeavour that might necessitate longtime monitoring of the accuracy and precision of the levels used.
Working with buildings that are valuable, whether for their worth or their historical merit, demands a level of carefulness that might require any number of specialised tools or techniques. Indeed, when surveying buildings likely to either already have subsidence issues or to be at risk of developing them, such as one located in Canterbury, a surveyor might employ controlled level and tilt monitoring, a watchful eye for any signs that the situation might be worsening, and a number of other techniques.
Subsidence Survey Methods
Monitoring fractures might not show all the details about your building, so you should have a complete check of your foundations and the nearby surroundings. You might need to drill holes in the ground against your building and examine the soil and water sample along with exploring trial pits that will keep you informed about the safety of your building’s foundation.
Other Canterbury Subsidence Causes
Conducting a subsidence survey means more than just watching for cracks to appear. To really get the kind of information you need when monitoring the overall structural health of a building – particularly a foundation – you have to also consider the types and amount of movement that might be occurring that just isn’t showing up in the surface evidence.
Fracture monitoring alone isn’t good enough. Building movement and structural health investigations need to involve drilling and excavation, both near the foundation and in the adjacent ground. You have to get down to the level of the foundation to see it, or to the type of monitoring that gives you a full picture of near-surface changes, which might also mean using some old-school methods like digging a trench.
Consideration of other subsidence causes is essential here because Canterbury has a number of environmental features likely to be important to subsidence. For one, the trees in and around the neighbourhood are potentially high-risk factors. Their roots are not very good at rheologically restraining soil. For another, the types of soil in the Canterbury area, particularly clay, also are a factor. Clay soil contains much more water than other types of soil and is prone to certain kinds of movement. Finally, we have to consider the location and condition of Canterbury’s subterranean drainage system.
Underpinning and Stabilisation of Foundations
If the foundation of a structure has shifted, there are means of correcting the problem such as underpinning. Underpinning, in its many forms – concrete, steel, or reinforced concrete – is the most common method used to stabilize and support a shifted foundation. The type of underpinning selected is usually based on factors beyond the control of the property owner, which are explained by your engineer or surveyor
Underpinning, involving ground excavation, must reckon with the likely impacts on nearby buildings or structures. When the ground moves and that movement affects a building or structure, it is possible to give special consideration and to do something about it via strengthening or other remedial measures when the cause of the movement is a failing retaining wall, landslip, slope instability, or creep.
The retaining wall systems and slope stabilization methods we employ offer the advantage of being shallow foundation systems, which means that they do not require large-scale earthmoving and are therefore much more economical.
Design and Project Management
Once the full scale of the job is understood, your building surveyor can prepare and oversee a remedial scheme. This ensures that the necessary work is undertaken smoothly and effectively. It might sound simple, but this is a complex juggling job that requires both oversight and understanding of the relevant technical and contractual matters.
Your surveyor or engineer will ensure the work is undertaken to the relevant standards, usually by preparing (or overseeing the preparation of) clear contract documents, tenders, specifications, drawings, etc.
The remedial program is then administered through a selection of contractors who are invited to tender for the building contract and cost analysis. This allows the necessary site inspections, contract administration, and control of contractor payments until practical completion. Most times, insurers seem unwilling to finance the expenditure and so your surveyor may need to assist you in negotiating this.
Expert Witness Islington
We offer the services of a panel of seasoned surveyors experienced in disputes. Your expert witness surveyor will prepare a Part 35 compliant report in accordance with the Civil Procedure Rules (CPR).
Schedule of Condition
A schedule of condition reviews the condition of the property at the date a tenant moves in or before any construction takes place. For both landlord and tenant benefit, the Schedule of Condition protects against any dispute that might arise over the condition of a property. It provides a baseline to prove whether damage has occurred as a result of tenancy or nearby works (e.g. party wall).
Contact Canterbury Surveyors
If you believe that your property is at risk of subsidence, a surveyor from our Canterbury panel will carry out a specific defect survey. The surveyor will visually inspect your property and look for signs of subsidence, as well as check the unfamiliar defects that have already called for a survey.
The subsidence surveyor will then determine what, if any, remedial actions need to be taken. These remedial actions will be the physical changes made to either your property or the area immediately surrounding it, to stop the subsidence problem from affecting you long-term.
