Structural movement monitoring is an important aspect of any construction project, as it plays a key role in ensuring the stability and safety of both the structure and the surrounding environment. Based on the type of monitoring required and the needs of the project, there’s a huge variety of monitoring solutions available that can be applied to ensure any issues are addressed promptly.
Structural movement can occur for a variety of reasons, including changes in the ground conditions, work being undertaken to the adjacent buildings or land, or thermal movement. Whenever extensive works are being done next to the flank wall of a property or a party wall, movement can occur during the project and upon completion once the structures settle.
The settlement could lead to minor cracks, and it’s critical to monitor these in case the movement is more than what was anticipated. Structural movement monitoring can be used to confirm whether the movement has ceased and the kind of remedial works that should then be undertaken.
When is Structural Movement Monitoring Necessary?
Detecting newly developed cracks in the walls and structural movement in a property is not a laughable matter. Movement monitoring helps put your mind at rest during building works by performing detailed monitoring and producing clear reports to monitor the movements of foundations and other critical elements over time.
If you want to undertake extensive structural works on your property, it’s highly recommended that you start movement monitoring early. This is especially important for any works that fall under the reach of The Party Wall Act 1996. Movement monitoring has become a common request from adjoining owners’ surveyors.
In case underpinning, party wall works or basement excavations are being done as part of the overall building project, a monitoring report will be essential to help you satisfy critical requirements and agreements with the neighbouring property owners.
The main goal of monitoring structural movement is to mitigate the risk of causing damage to adjoining properties, and thereby avert unnecessary inconvenience to the adjoining owners. Local councils will often recommend that the risk of ground movement be adequately addressed by having movement monitoring performed throughout the project.
The following are examples of work that may require movement monitoring:
- Cutting or removing reinforced concrete slabs from a party wall.
- Demolitions and piling work.
- Large engineering projects
- Excavation work to create a basement.
How Structural Movement Monitoring Works
Movement monitoring typically involves the installation of reflective targets at specific locations on the structure being monitored. They are typically installed in the rear, front, and flank walls of the adjoining owner’s property. Movement is then monitored by periodically measuring the targets using electronic distance-measuring instruments.
The accuracy of the measurements is +/- 1mm. The engineers will agree on a reasonable level of acceptable movement, where work will cease if movement exceeds this level. The project’s contractor and team will then have to agree on the best course of action to prevent the occurrence of further movement. In case there are significant cracks already present before the work commences, it might be more suitable to measure the cracks individually and using a tell-tale crack monitor.
The cost of doing this will largely depend on the size of the project and the length of time movement monitoring will be required. It’s recommended that monitoring be put in place with base readings done before the work begins.
Based on the kind of work being undertaken, readings are measured as frequently as needed, which could be as much as once a week. If damage is detected at the adjoining owner’s property, it might be imperative to ascertain whether the movement is continuing or has stopped before advising on remedial options. Still, the more visits are needed, the more expensive the monitoring will be.
The Significance of Structural Movement Monitoring
Safety Assurance: The main goal of structural movement monitoring is ensuring the safety of the people who live, work, or visit the structure. Detecting signs of a potential failure or instability early enough can help prevent catastrophic events.
Preventative Maintenance: Structural movement monitoring also enables engineers and contractors to identify issues before they become critical. This proactive approach can help save money by addressing problems before they escalate.
Data-driven: Monitoring provides valuable data for making informed decisions about the renovation, construction, retrofitting, or even decommissioning of structures. It also provides actionable insights into the structural changes that have occurred in and around the structure, to ensure that the property and the surrounding one remain in good structural health.
Environmental factors: Environmental conditions such as humidity, temperature, and soil moisture can have a huge impact on the stability of a structure. Monitoring will help assess the effects of these factors and help the team plan accordingly.
While structural monitoring might seem like a high cost to the building owner, it’s ultimately beneficial. The process will help the owner avoid the potentially extensive remedial costs for repairs to the adjoining properties, not to mention the fees in resolving the dispute under the law.