The Klingler Group, Construction Consulting Solutions
Case Studies
The Klingler Group

The Case of the Roof Leak that Wasn't

BACKGROUND

Called on by a luxury resort time share company in north Scottsdale, Arizona, The Klingler Group was asked to locate the source of chronic leaks in a closet in one of their specific model designs. Over a course of two years, all efforts to remedy these leaks had failed, resulting in costly investigations, repairs and reimbursements of damage to tenants' personal articles, not to mention lost revenue opportunities.

As often happens, the failed repair attempts were done without a proper evaluation. Particularly in the case of water intrusion, which brings an obvious urgency, hasty decisions may get made. In this case, based on stain patterns, the erroneous assumption was that a leaking roof was the cause. If they were ever going to solve the problem, the property owners determined that an independent assessment was going to be necessary.

EVALUATION

The Klingler Group is often called to follow up on unresolved matters. Our hands-on experience with all aspects of construction allow us to identify, and properly eliminate, possible causes. And we bring in the proper team with the right skills to evaluate specialty items in order to investigate more than past performance and patterns.

In this evaluation, we considered four primary elements:
1. Design and construction
2. Climate and exposure
3. History of leaks
4. Patterns of water intrusion

1. Design and construction
We discovered that at each of the affected units, the patio soffit and exterior cladding assembly consisted of an EIFS (Exterior Insulation Finish System) installed over metal framing that incorporated masonry transverse shearwalls running across the width of each multi-story building and making up the back wall of the leaking closets.

Other building components we considered as possible sources of water intrusion, besides the roof, were the sheet metal caps serving as termination points for various building components and the sump-type, through-deck roof drains for directing and discharging storm water.In addition, the transition metals, handrail penetrations, floor construction, plumbing, fire sprinkler, mechanical conditions and other elements could cause or contribute to failed performance.

2. Climate and exposure
As the leaks appear to occur during rain events only, determining the building's source of unwarranted weather exposure was significant. Based on our experience, their type of roof membrane system would not be suspected to leak, and the EIFS system, if properly sealed at transition points, would perform very well. While testing would be needed for confirmation, we felt confident that we could eliminate mechanical failure.

3. History of leaks
We met with representatives of the building's contractor, who shared the history regarding the repeated past water leaks and attempts to remediate. The attempted repairs did little to discount any of the assumed possibilities, and aware that they were performed without identifying the true source, we questioned the procedures followed. All we knew for certain was that the leaks persisted and the contributing element was some part of the building envelope.

4. Patterns of water intrusion
We often tell clients: Patterns tell a story. In this case, some efflorescence and staining were patterns that would help to identify the source of the leak. However, while patterns are key, they often lead to wrong decisions based on false assumptions. For example, many professionals look at the EIFS system and disregard the underlying substrate materials. Most roofers consider only the roof assembly. We consider all aspects that might come into play.

INVESTIGATION

Based on our initial findings, we developed a plan to perform water testing while incorporating the use of an inferred (IR) camera/imager. The images collected would identify the existence and location of moisture within the closet and surrounding finishes. To perform this investigation, we engaged the services of a certified, EIFS consultant, Exterior Stucco Consulting (ESC). They had agreed that the EIFS was installed appropriately and was not likely the culprit.

The location and pattern for moisture found with the aid of the IR camera eliminated many of the potential water sources. As a result, further investigation of the construction would need to be performed. Interior gypsum wallboard was removed to expose the masonry wall and enable us to examine the cavity. The next step was a roof water test, in which we flooded the roof for close to one hour while checking for migration of water into the closet below no additional moisture developed. We continued to systematically expose various parts of the building envelope and introduce additional water, and still no new signs of moisture.

We therefore deduced that the water must have come from another source entirely, and we extended our investigation to the unit located one level up and directly north. Viewing the deck there, we found evidence of water pooling and staining, suggesting that water was not fully draining off the leading edge; rather, the water was directed to the south, the side closest to the subject unit. Further examination revealed a void in the deck-to-roof metal and membrane along this same location, providing a ready avenue to the lower unit. Pouring water onto the deck surface and letting it find its way, it quickly drained into the open cavity. Within 30 seconds, the water found its way to the closet, approximately 20 feet away.

CONCLUSION

The IR camera pinpointed the location of concern and systematic testing provided for the process of elimination, allowing us to pinpoint the specific source and deficiency. The problem, which was believed to be a roof leak, ended up being a design flaw and workmanship mistake at a deck juncture some 20 feet away. This discovery helped identify the leak source for every unit of the same design within the entire complex.

Water intrusion leaks can be very complex and frustrating to evaluate, and the inclination is to act as quickly as possible. However, this often results in recommendations for repairs that are ill-advised and ineffective, wasting time and money. Much of the work we do is to follow up on these efforts and to find the true cause. With the right knowledge, experience and equipment, we have the ability to conduct a forensic building investigation to find the true cause that will lead to the proper remedy of any construction problem.

see also:

Roof Collapse
Interstitial Condensation
Damage Caused by Drainage Issues
"Punch List" Inspection Prevents Disaster
The Leaky Roof and Pitted Clay Tiles: A Closer Look

Water path indicated by arrows

Void at deck which allows water to enter soffit cavity

Water intrusion at closet behind sheetrock

Inferred image at closet lid above metal framing: dark blue indicates water intrusion location