Non-destructive testing (NDT) gathers preliminary information, using technology and equipment, to inform next steps for repairs or further action, including more invasive destructive testing.
NDT is a toolbox of techniques CANY brings to a much larger scope, saving time and money for the client, better use of resources and focusing efforts on complex jobs. Our NDT capability fosters a better workflow, facilitating face-to-face, on the job interactions, avoiding cumbersome delays and protracted processes.
When assessing a building to determine the root cause of an issue, even our well-trained eyes, ears and extensive experience can only take us so far. We set up a working hypothesis that we test using NDT to either validate, establish a new one, or confirm the required scope of works. NDT uses a variety of tools and technology to gather as much information as possible, to minimize disruption to the use and fabric of the building, and determine the most likely explanation for what’s going on.
NDT is precise, allowing, for example, investigation into concrete slabs without damaging the supporting infrastructure, utility conduits or hidden waterlines. Ground Penetrating Radar (GPR) could be calibrated for a variety of materials, e.g. to detect concrete, air pockets, rebar, or anything other than concrete. GPR is also used for wall tie detection in conjunction with metal detection, delivering information faster, and cheaper than traditional destructive investigations such as probing.
NDT determines where and how a leak is damaging a building. Spray testing targets specific details of a building, often in conjunction with an infra-red camera. The camera minimizes potential damage and identifies leaks invisible to eyes. It detects changing temperatures, cold spots, points of water ingress or where trapped, like under a roof membrane. Temperature changes do not always indicate a leak, so moisture meters are used for verification.
Infrared thermography provides thermal analysis to detect energy loss through different parts of a building, highlighting failures of insulation and/or fenestration and where to focus to mitigate against such loss.
Acoustic testing evaluates material conditions. From a plastic mallet tapped against terracotta listening for sound variations to locate a spall, to high-tech ultrasound equipment to assess corrosion of steel structurally supporting buildings and facades. Acoustic testing helps determine the location, extent of damage, and whether to repair or replace by measuring the thickness of the remaining steel.
Borescopes are small cameras on long thin wires that get in the tight spaces and under the skin of buildings. They are especially useful in restoration work as they cause minimal disruption but get eyes in places that would ordinarily incur damage to be properly assessed.
Metal detectors locate the position of anchors and rebars, and GPR assesses their condition. If the GPR detects an anomaly, minor destructive testing will confirm it and obtain calibration data to apply across the whole project. Using other collected data with similar response patterns raises confidence that other anchors behind the stone are in a similar condition and need addressing.
There will always be uncertainties in NDT, nothing is exact or conforms to a cookie cutter pattern. Assessing data provided by non-destructive testing, and applying it correctly within the context of the building and the materials, can offer a wider survey area in a shorter time frame than physically opening sections of a building. However, correctly interpretated and performed NDT will only offer an informed opinion. It is only when the building is destructively tested, opened so that an issue can be physically seen, that the data can be confirmed.
At CANY, we have the knowledge to know what we don’t know. We rely on as many resources as possible when making our judgements – that could be using our senses, including sight, hearing, touching, and feeling, plus a range of technology and devices. But the tools are only as good as the people deploying them, and we know through almost three decades of experience, that no amount of technology can replace our inherent understanding of buildings, but NDT can enhance it.
To talk to someone about how our NDT capabilities can help identify an underlying problem with minimal disruption, contact Thomas Seminara, Chief Business Officer, at tseminara@cany.com.
