Got Leaks? What you Need to Know from an Engineer’s Perspective

Article by Belanger Engineering

Belanger Engineering carries out Condition Assessments and Repair Planning for buildings and individual building components. Our reports include detailed explanations of existing conditions, recommended repair philosophies/strategies, repair/replacement cost estimates and any other pertinent information that will aid the owner in the decision making process.

There have been a number of occurrences of reported water leakage at properties. We have extensive experience in this area. While each project is evaluated on its unique conditions we have established a protocol that serves us and our clients well in achieving a high rate of success while minimizing related costs.

Our work typically begins with a visual review of the suite interiors or common element areas at the reported leak locations. An initial assessment is made, and the point of water evidence is recorded. From our perspective, we gain greater knowledge from the owners and staff as they are able to provide valuable details that will help with our initial assessment.

The pattern of leakage is often instrumental in solving leakage issues. By way of example, valuable information can be gleaned based on the history of the leakage. Leakage that suddenly develops is often the result of changes in material conditions and we focus initially on sealants, waterproofing membranes or other components such as roofing materials that may have been damaged/deteriorated resulting in the leakage events.

Terraced properties often experience persistent leakage at the terraced areas simply due to the interruption of the exterior building walls at each such terrace. Water that penetrates into the wall assembly above a terrace can flow downward through the wall assembly until it is obstructed by the terrace floor slab. In these cases addressing the point(s) of water entry can provide immediate relief to the leakage; however, subsequent sealant or material failures can be expected to once again cause leakage into these suites.

In many cases, flashing changes can be done to minimize or prevent such persistent damages to the interior and the related inconvenience and disruption to the residents.

Minor leaks can go unnoticed by owners for long periods of time until they manifest in visible damage into the interior finishes, such as stained hardwood, stained carpets and drywall damage. Minor leaks are often the most difficult to detect. In our experience water testing is not often the most cost effective way to handle minor leaks as the water penetration is not readily detectable unless the interior finishes are removed.

We try to provide owners with knowledge on how to prevent certain types of leakage. For example one common mistake owners make is leaving their exterior sliding windows open while closing the interior slider only. Doing that during a rainfall allows the water to directly penetrate the sliding window tracks and enter the wall systems.

Many owners believe that shutting the interior sliding window is ok; however, most are not aware that the two sliding window tracks are designed differently. The exterior window tracks are fitted with drains so that water is directed to the exterior of the building. The interior sliding window tracks are not fitted with drains, therefore allowing the water to be trapped and accumulate.

This condition can result in an overflow of rainwater at the window track resulting in damage to the interior. In addition, over time the serviceable lifespan of the internal window seals are reduced due to prolonged exposure to moisture. The seals deteriorate and breakdown which results in leakage and ultimately leads to replacement of windows being required.

Condensation and condensation damage is also a major concern for most owners. Some condensation is expected in units and is considered normal.

Most typical hi-rise residential buildings are equipped with makeup air units located on the rooftops. These units supply conditioned air to the corridors. This air is normally a few degrees cooler than the interior air of the building. This supply of cool/dry air absorbs moisture as it passes through the units and dispels the moisture to the exterior by bypassing the seals at the sliding windows. Moisture is also exhausted through the kitchen, bathroom and dryer vents.

A few tips to alleviate excessive condensation are as follows:
• Don’t install seals around the perimeter of the suite entry doors as this restricts the supply of makeup air into the suite resulting in excessive buildup of humidity;
• Ensure the exterior and interior sliding windows are fully closed and engaged at the interlocks;
• Operate the dryer exhaust fan while doing laundry;
• Ensure the dryer lint trap is clean and maintained in a clear condition;
• Ensure the lint trap in the duct work is maintained in a clear condition;
• Operate the exhaust fans in the washrooms while in use and for at least one half hour after bathing;
• Operate the kitchen exhaust fans while cooking (if so equipped);
• Minimize the use of humidifiers, steamers, rice cookers, etc. and at times when excessive condensation issues are present.

Belanger Engineering takes great pride in helping to address our clients’ needs and providing safe living conditions for all owners. We focus on expanding our value to our clients and their agents by providing holistic building science solutions.

We promote and ensure the superior delivery of consulting services so our customers experience excellence every time.

For More Information:

Belanger Engineering Team
Phone: (905) 795-9997
Web: www.belangerengineering.ca

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