Overview of Building Canopy Inspection in Hong Kong
When building canopy inspection takes place, what is intrinsically being looked into is the integrity and the stability of a particular canopy. To be clear, a canopy is a structure that provides a covering, often giving shade, and is an overhead roof that juts out from the main building. The safety implications of a canopy that is not in good condition or up to building standards is clear, and it is up to a developer or property owner to ensure that building regulations are adhered to and that a property’s inhabitants, visitors and the general public within the vicinity are not in harm’s way.
Because of the nature of a reinforced concrete canopy, vulnerabilities are inherent, and with this, specific types of testing and assessments are required to be carried out. These range in terms of comprehensiveness, from visual inspections to non-destructive and also destructive tests. Canopies are designed to protect people from the elements, for example rain and sunshine, and as such they are exposed to the elements themselves. Concrete structures by their very nature can be succeptible to specific issues that need to be identified and consequently resolved.
Where problems are inherent, visible signs may be obvious, requiring further investigation to pinpoint the extent of the problem. Hammer tapping is a test that essentially evaluates the strength of concrete and its elastic properties, looking at surface hardness and penetration resistance.
A non-destructive test is the use of an electromagnetic covermeter, with a survey carried out to detect reinforcements within the concrete. This gives an impression of the quality, strength and condition of a canopy. Meanwhile, an open up survey is invasive but may be deemed necessary to get a fuller picture of the status of a canopy’s condition.
Water seepage can also be investigated, as well as tensile testing of reinforcements, along with a corrosion survey. Carbonation may need to be established along with its depth, by determining the chloride content. Crack mapping is a way of identifying where there are cracks within the concrete, which in essence is primarily caused by shrinkage during the drying process. The extent of cracking and how destructive it can be needs to be identified before a full report is made on what any possible solutions are, and the time and cost implications of these.
Overall, strength, water resistance, durability and condition of the concrete are assessed during a canopy inspection, and the sooner problems are discovered the better.