Repair History is Critical to Proper Inspection of Building Envelopes
Managers also must develop a reactive strategy that addresses any discovered problems. When maintenance budgets are very tight, it is common for managers to ask window washers or repair contractors to caulk any component suspected of causing leaks. While this might be a fast, cheap, and simple way to deal with the problem, the chances of its success are limited if the actual source of the leak is not obvious, open, and accessible.
Interfaces are a critical part of the building envelope, so it is important technicians use sound methods to accurately diagnose problems. Inspection and diagnosis should be based on inspection and testing that follows a logical plan to eliminate guesses, which can generate unnecessary repairs.
Providing the inspector with information about past leaks and associated repairs, current leaks, and a description of the circumstances under which the leaks occur can mean the difference between guessing and being able to focus directly on a targeted area.
If the inspector discovers leaks, the next step is spray testing to identify the source. ASTM International Standards outline the use of a calibrated spray rack, as well as a test method using a handheld calibrated spray nozzle. When testing, it is important to attempt to recreate leak patterns observed under service conditions. It is possible to create false leaks that would not occur in nature, meaning maintenance and repair programs might not need to address them.
Whether a manager employs a proactive or reactive strategy, one good place to start looking for problems is the interfaces of systems and components. Sealant joints might outwardly exhibit failures where the sealant has cracked or split open or has simply aged due to long-term exposure. Adhesive failure occurs when the sealant's bond to the substrate at one or both sides of the joint deteriorates.
This problem often is visible, but it is possible for the sealant to appear intact. Unless the technician presses or pokes the joint to reveal the bond failure, this potential leakage source can go unnoticed. Technicians can use rollers designed for mounting insect screening into window screen frames to check sealant joints.
When it comes to minimizing building-envelopes repairs if problems develop, a proactive strategy for the inspection and maintenance of building envelopes is always preferable to a reactive strategy. The inspection of a representative sample of the building typically focuses on the interfaces of the cladding system with other components or systems. In some systems — for example, curtain walls and storefronts — the inspections should focus on the component-to-component interfaces.
Managers or building envelope consultants can develop a proactive inspection-and-maintenance plan designed to help the organization avoid or minimize major problems. But in situations where a leak is reported and a reactive approach is required, proper diagnosis of the leakage source allows managers to more effectively and appropriately allocate repair funds.