Systems Analysis

Tight houses and changes in building materials are only the beginning. Understanding how all the components in your buildings work is also essential to preventing mold -- including HVAC systems, cladding, lawn sprinklers, and grading, depending upon climate.

While redesigning wall sections may sound like starting over, there's a lot of help out there. Thanks to energetic researchers and consultants, there is a nationwide network of experts tracking moisture incursion incidents and recommending solutions. "Builders tend to screw up the same way as each other around the country, pointing to which mistakes are made where," says Environomics' Nassof. He and other experts agree and strongly advise builders to carefully tailor their buildings to their climates. They also say it's essential to understand how all the materials you build with work -- and determine how they work best together as a system. Companies like Environomics, Building Science, and Building Knowledge, and Web outlets like the Energy & Environmental Building Association's www.eeba.org offer climate-specific training for builders. Research is available from the NAHB, too, and at other sites.

Yost points out that all the elements in a house are related and function in unison -- or in contrast -- to one another, and understanding this system is the key to building a house that'll stay dry. "There are very few bad building materials," he says, "but the permutations of bad applications are limitless," pointing to how complicated the detail-decision can be.

High Performance

"We're asking more from our homes than ever," says Yost. In the recent past, homes were built more to keep water out than to keep heat in. Since then, air conditioning, better heating systems, and the 1970s OPEC crisis required us to build more thermally efficient, yet affordable, products. That's why Yost calls the modern home "high performance." A building does much more than we've ever asked of it in history. And, it often must be built faster with much more-specialized workers. Lightning-fast production schedules and untrained or highly compartmentalized employees lead to mistakes if properly detailing a building penetration requires patience and expertise. All of these forces combined in the last five or so years of record home starts and remodeling activity to create the unintended consequence of mold thriving inside the most advanced houses in history.

As we change what houses do and how we live in them, controlling moisture and creating high-performance buildings you're proud to have your sign in front of is a complex process. It requires changing how we think about building and managing a lot more than water coming at the it from the outside.

HANDLING THE PHONE CALL

Having a mold protocol in place will help you deal with customers' anxieties if they call with a moisture-related question or complaint. Experts Russ Nassof and Bob Rudd recommend the actions below as a preliminary checklist, but also recommend developing a relationship with a professional mold investigator so you can be ready with a quick remedy in case the worst happens.

• Response time is vital. If you don't answer the office phone directly, call back as soon as possible.
• Once the homeowner is on the phone, let them talk as much as possible. Don't interrupt their story. Take detailed notes.
• Document everything -- times, dates, locations, who you're on the phone with, and what they say.
• Get to the site pronto. Stop the water, then determine quickly if you can fix the problem or if it must be handled by a third-party professional.
• When fixing a defect, photograph all stages of the correction process: What it looked like when you got there, what actions you took, and what it looked like when you finished. Digital photography is often best because the camera can time- and date-stamp everything.
• Are there sensitive people on site? (Children under 4-years-old, elderly, immune-compromised.) For a large incursion (i.e. a burst water pipe) that has been there for more than 72 hours, suggest removing them from the site until an investigation can be completed.

The Dirty Dozen

Peter Yost at Building Science Corp. outlines the top 12 places his company finds moisture and mold in residential structures. Remedies vary per site.
1. Behind tubs on outside walls
2. Second floor cantilevers
3. Fireplace build-outs/cavities
4. Plumbing/electrical penetrations
5. Rough openings (chimney chases and windows)
6. Attic access -- scuttle holes and fold-down stairs
7. Intersecting inside/outside lines of interior walls and roofs
8. Interior soffits terminating against outside walls
9. Carrying beams extending from inside to outside space (in basements as well as in timber-framed structures)
10. Recessed can lights in thermal envelope
11. Assembly transitions (roof framing to top of second story wall, rim joists, slab to sill plate, etc.)
12. Sheltered spaces, most notably air sealing between attached/under garages and living space

RESOURCES FOR SUCCESS

Building Science Corp.: www.buildingscience.com
Building Knowledge Inc.: www.buildingbetterhomes.com
Construction and Environmental Training Institute: www.constructiontraining4u.com
Energy & Environmental Building Association: www.eeba.org
Environomics: www.environomics.com
The Journal of Light Construction: www.jlconline.com
The National Association of Home Builders (NAHB): www.nahb.org
The NAHB Research Center: www.nahbrc.org
National Center for Housing and the Environment: www.housingandenvironment.org
The Insurance Information Institute: www.iii.org
Dr. Fungus: www.doctorfungus.com

-- Mark Clement is executive editor of Tools of the Trade.