ICS Magazine

Structural Drying: Residential Vs. Commercial

December 21, 2010

Commercial buildings aren’t just large houses. And when it comes to water damage, there are major differences in the techniques used to dry them.

Most houses are built for a single purpose – for people to live in. Commercial, industrial, institutional and complex residential buildings, however, have many purposes and applications. They may be constructed for retail sales outlets; nursing homes, medical offices and hospitals; funeral homes; conference and convention centers; office complexes; private or public schools; city, county, state or federal governmental offices; sports facilities and numerous other institutions.

Commercial, industrial and complex residential buildings also vary greatly in size, from a 1,000-square-foot beauty salon to a 1-million-plus-square-foot convention center.

Size and Intricacy of Building Systems

Restorers should be certain that they understand HVAC zones and realize that positive outside air makeup systems require re-thinking of dehumidification needs. Other building systems to be aware of include sprinkler and other fire-suppression systems; computer systems, networks and clean rooms; complex HVAC systems with multiple zones for air distribution; elevator shafts and systems; stairs and stairwells (consider stack effect), and hard-wired telephone and computer systems.

Power Distribution

The electrical distribution systems in industrial, institutional, commercial or complex residential buildings range in complexity, in the amount of voltage and amperage, and in the training and licensing required to qualify technicians for work on this equipment. Residential power is typically 115-volt (15 to 20 amp), single-phase 60 hertz or 220-volt, single phase 60 hertz. Most commercial buildings, in addition to the lower voltages (higher amperage) circuits, will have 230-volt, 3-phase 60 hertz or 460-volt, 3-phase, 60 hertz.

Low-voltage and special wiring systems – e.g. alarm and security systems, central video and audio communications, lighting and hard-wired computer networks – can be particularly sensitive to contamination and corrosion. Sophisticated energy management systems (EMS) require special understanding. Restorers should not assume that they can change an EMS to reduce or increase outside air makeup requirements, they may even need to be managed off-site. Coordination with building engineers to adjust or over-ride these systems may be necessary.


There are many challenges related to public access and security that can easily increase the time required to mobilize equipment, move equipment around and for monitoring a job:
  • on-site security must be handled properly
  • security clearances may be required
  • personnel and equipment logs are essential


There are usually multiple stakeholders or materially interested parties (MIPs) on a restoration project, leading to more complicated levels of project management or administration.  Restorers must be aware that MIPs have their own agendas and think their area of need is critical and more important than anyone else’s; proper paperwork systems and communication are essential to increase understanding on the part of all MIPs, and to avoid future litigation.

Establishing a chain of command can be important. There can be multiple reporting requirements (owners, managers, insurance professionals, municipal or state regulatory authorities, or licensing bureaus). Conducting site-specific safety meetings is essential and appointing safety officers is mandatory. Scheduled daily (often morning and evening) meetings with MIPs and stakeholders should be the norm.

Construction Types and Practices

Commercial construction practices, materials and codes are complex, and they vary from one jurisdiction to another.  Restorers should be aware that the construction system you do not research, inspect and understand will be the one that sinks you! Consider:
  • old vs. new construction practices.
  • multiple renovations often introduce unexpected construction requirements.
  • building codes change over the years, but many retrofits are never done.
  • neglected routine maintenance over time may lead to significant building deterioration.
  • microbial contamination due to deficient construction (leakage) may be pre-existing.
  • previous work by unqualified or unlicensed contractors may cause significant safety hazards to exist.

Job Site Safety and OSHA Compliance

In residential structures, safety hazards usually are limited to asbestos, mold, bacteria, common ladder safety, or the usual slip-and-fall hazards. In commercial structures, in addition to multiple physical accident and injury hazards, HAZMAT can include, but is not limited to:
  • lead
  • asbestos
  • polybicarbonated biphenols (PCB)
  • fuels or other dry solvents
  • mercury
  • arsenic
  • microbial contamination
  • bloodborne or infectious pathogens
There may be all of the above plus hazardous chemicals present, energized machinery requiring lock-out/tag-out, confined spaces, scaffolding needs, larger equipment to move requiring forklifts and higher voltages.

Restorers must discuss the facility’s safety program to help understand identified hazards and controls in place. The contractor must consider environmental hazards resulting from the loss, hazards that may be present as the result of the normal business operations of the client, and hazards that may arise in the course of making repairs, e.g. scaffolding, confined space, use of lifts/special equipment.

Bottom line: the challenges present in residential structure drying are multiplied and compounded in complexity in the commercial, industrial, and complex residential segment. Therefore, it behooves serious drying technicians to investigate and advance their education on these challenges before they jump from the frying pan into the fire.

 Responding to these challenges, the Institute of Inspection, Cleaning and Restoration Certification (IICRC) has created a new certification category, Commercial Drying Specialist (CDS). The IICRC website, www.iicrc.org has a listing of CDS classes that will be taught in the near future.