Leak Investigations & Non-destructive Testing
Water will find the path of least resistance. Finding the weakest links in a building’s waterproofing envelope water can make its way into and past building systems despite recent advances in building materials and construction methods. Moisture penetration into dwelling units is a major issue, but water can also severely jeopardize the structural integrity of a building.
Leaks announce themselves in numerous ways: discoloration, bubbling paint, loose tiles, moisture, mold, corrosion, and various other manifestations. However, since water continues to follow the path of least resistance even after it has penetrated the building envelope the source of the leak can be harder to find. Most leaks start at the exterior envelope, whether at the roof or along the walls. The culprit is often where to building elements meet, at joints and transitions. Other areas of concern are at openings in the building envelope such as doors, windows, or through-wall air conditioners.
On occasion, the leaks stem from within the building (typically plumbing leaks or from condenser lines). As they travel along building elements before revealing themselves, the source of the leak may become obscured. Ground- or rainwater can also seep up through foundation walls or the basement floor.
Evaluating the source of the leakage is further complicated by the fact there may be several sources. An investigation must follow a rational methodology, underpinned by knowledge and experience, to avoid false starts and expensive mistakes. Understanding the properties of individual building types and elements is necessary to develop the investigative activities and their sequencing.
After reviewing any available documents such as drawings and repair records, the investigator typically begins by interviewing residents and building supervisors. Finding out whether the leaks relate to weather conditions, if they happen irregularly or on some other schedule, or are continuous can often help determine the source of leaks. A visual survey of the reported leaks follows. When carried out by an experienced Architect or Specialist this will often provide actionable results or help create a protocol for further investigation or non-destructive testing.
Methods
A thorough visual inspection may involve a high resolution camera with a flash, a flashlight, and mirrors. New York Restoration Technology’s non-destructive testing methods include infrared imaging, moisture meters, spray bar, and drip testing. Infrared imaging reveals thermal variations that may be the result of moisture infiltration. Moisture meters rely on impedance testing to determine the relative moisture of materials. Drip testing and spray bars are used to simulate the effects of rain and driving rain.
Repair work should always begin at the source of the leak. Patching the damage or superficial repairs will always cost more in the not-so-long term. New York Restoration Technology will assist in developing detailed repair plans and a timeline staggering such work. The overall most cost-effective option is to regularly maintain the building envelope and thus avoid leak investigations and repairs entirely. New York City’s Façade Inspection and Repair Program can be an ally in the effort to head off costly repair work, as these required evaluations often reveal minor problems before they become major issues.
