A library in Itasca, Ill., had leaky windows.
The library was only about 10 years old. It was an award-winner too – for design. It was clad with DAFS – Direct Applied Finish System. As you probably know, this system is similar to EIFS – Exterior Insulated Finish System, except it doesn’t have the insulation.
What it did have was mold.
That was revealed during the investigation by Building Envelope Consultants Ltd., Arlington, Ill. The investigator, firm principal Kami Farahmandpour, said the city was lucky. The mold hadn’t penetrated to the library interior.
Nevertheless, the cladding had to come off so the contaminated wall components could be replaced.
Building Envelope Consultants prescribed a new air- and water-resistive barrier, a redesigned drainage system, new leak-proof windows, and recladding in conventional 3/4-inch stucco.
In the end, the library’s exterior appearance didn’t change much, but beneath the stucco skin the components were altered significantly, giving the wall a much better chance against buildings’ worst enemy – uncontrolled water movement.
About 90 percent of Kami’s business comes from building owners with problems like the Itasca library. The rest comes from design professionals seeking to avoid those problems to begin with.
Kami, an engineer by training, and forensic building detective by experience and predilection, wishes it was the other way around – 90 percent avoiding problems to begin with.
The issue, he says, is the incredible and increasing complexity of contemporary wall systems. Long gone are the days of simple, thick masonry walls.
We ask walls to do a lot more today, Kami says. We demand all the durability, performance and aesthetic appeal of solid masonry walls, but we want it cheap, light and code-compliant.
Handed those requirements, the industry has come up with hundreds of products that can be used in thousands of combinations. Results range from walls that prevent costly, destructive air and water leakage in conditions up to and exceeding Category 5 hurricanes; to walls that leak air and water; trap moisture; grow mold and deteriorate in alarmingly short periods of time in even the most benign climates.
Getting the right results means navigating a sea of curtain walls, panel walls, precast, thin brick, CMU, air barrier systems, vapor retarders, flashing systems and much more.
Some places, like hurricane-prone Florida require impact-resistant walls and windows.
Some clients, like the federal government, require blast-resistance in their building envelopes.
It’s no more reasonable, Kami says, to ask an architect to be familiar with every combination and location of every system in every kind of wall assembly than it is to ask a general practitioner M.D. to be familiar with every medical aspect of the skin.
There are, after all, general practitioners and dermatologists.
Throw into the mix the fact that new products and procedures for building envelopes – let alone other components of buildings like security systems, flooring or HVAC — emerge at a dizzying rate.
Add in that each new product needs careful, usually time-consuming research and evaluation before consideration, and the reason for the emergence of the building envelope consultant starts to come clear.
Kami says he understands the reasons design professionals have been reluctant to take advantage of the resource offered by the new specialty.
Professional pride may be part of it, he says. Also, design professionals can be hesitant to divvy limited budgets even further, especially when they’re using wall systems with which they’ve had success in the past.
On the other hand, clients, insurance companies and lending agencies sometimes require the participation of a building envelope consultant as assurance things won’t go south from water leakage after project completion.
All have been bitten by it, Kami said. Water leakage is one of the most litigious areas of construction.
A few simple questions can give you an indication as to whether or not you could benefit from talking to a building envelope consultant.
Building owners – Does your building have a water leak, or premature deterioration of wall or roof elements, but you can’t pinpoint the cause? Do repairs not seem to fix the problem?
Design professionals – How aware are you of the different purposes and uses of vapor-permeable and non-vapor permeable air barriers, and where each should be located in the various kinds of wall assemblies? How “up” are you on the latest products and procedures from the major manufacturers of building envelope components? How familiar are you with integration of different types of cladding – masonry and EIFS, for instance — in the same wall assembly?
If you’re vague on these questions, Kami says, you may want to get in touch with people who spend all their time studying and working on these specific issues.
Sealant, Waterproofing and Restoration (SWR) Institute and RCI Inc., are both good places to find reputable consultants, Kami says. RCI Inc., is an international association of consultants, architects and engineers specializing in roofing, waterproofing and exterior wall systems.
SWR Institute membership comprises more than 230 leading commercial contractors, manufacturers and consultants.