Learn how climate control, construction risk management procedures and site management can help preserve your building.
The volatile economy and downturn in new construction have forced many building owners and developers to put their building projects on "pause." But halting construction can be an extremely risky business decision.
An unfinished structure is often unprotected from temperature extremes, high humidity and a host of other ambient conditions that can damage or warp materials and cause mold growth. The structure is especially at risk if the facility's mechanical system is not yet operable.
To protect buildings in "pause mode," owners and facility managers should consider the use of desiccant dehumidification to control the indoor environment. The goal: Preserve the interior including building materials and contents to protect against damage and corrosion caused by too little or too much humidity, control heat/cold temperatures and prevent mold growth.
A Viable Response
Temporary climate control for a building under construction is an efficient and cost-effective process. It is an extremely wise investment-the cost for not protecting a building is potentially far more expensive if remediation is necessary from damage caused by weather.
Many owners opt to enlist desiccant dehumidifiers, ideal because of their effectiveness to create low relative humidity and dew point temperatures at any temperature. They also often eliminate the need for heat, saving a considerable amount of energy.
Desiccants can attract and hold from 10 to more than 10,000 percent of their dry weight in water vapor. Portable desiccant dehumidification units are designed to provide the aggressive drying required to establish proper humidity tolerances.
The units are built to handle the rugged construction environment and can be operated by electrical power, if available, via temporary generator power or by a natural gas line or propane gas supply.
Portable, inflatable plastic ducts are used as part of the airflow system, precluding any reliance upon the building's permanent HVAC system. Also, temporary ducts are easy to move and often placed in sensitive areas.
Aside from maintaining a dry environment, these units will prevent mold growth by reducing humidity levels. This is a critical benefit: Many insurance companies restrict their coverage to construction contractors due to the effects of mold, mildew and water-related damage during construction.
Preparing the Building for Preservation
Once the decision is made to utilize desiccant dehumidification in a construction "pause" project, it is time to prepare the building. There are many factors to consider.
It is important to recognize that controlling the climate in a "pause" project usually is a unique process based on the structure itself. Parameters include the size of the building, number of floors, existing and targeted temperatures and humidity levels, dehumidifier capacities, building materials and configurations of the structure, including openings and air flow. Preparation can take a few hours to a few days.
In some cases, heating and cooling systems are utilized in conjunction with desiccant dehumidification, depending on the weather conditions in that region of the country.
A building owner or manager must then consider stabilization of the structure, air exchange rates, make-up air amounts and control point settings.
The reality of most building sites is that the building envelope is incomplete or in some cases not all areas within the structure are moisture sensitive. For a building to be effectively controlled, the use of temporary walls and containments is necessary to ensure that dry air from dehumidifiers is contained.
Construction firms also should consider the necessary air exchange rates. Air exchange parameters for buildings under construction are dependent upon the size and conditions of the building air and temperature requirements. These rates can range from one-half to more than two air changes per hour. Typical requirements are one-half an air-change in a given space.
Determining the air exchange rate is done by calculating a moisture load on the structure. The number and placement of dehumidification and heating or cooling equipment are then determined by analyzing this moisture load.
A common question for many is whether the "pause" building requires make-up air if it is not occupied, according to American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 62. Essentially, the answer is no.
The purpose of this standard, as defined in Section 1, is to "specify minimum ventilation rates and indoor air quality that will be acceptable to human occupants and are intended to minimize the potential for adverse health effects." When a building is protected, however, it either has a limited occupancy or is not occupied at all, and little or no make-up air is required.
Setting control points is another important factor in building preservations. These guidelines ensure that two major problems are avoided- corrosion and mold. Generally, humidity levels should be maintained below 50 percent, and ideally between 30 and 50 percent. Mold growth is controlled with humidity levels below 50 percent. It is strongly recommended that you monitor levels on an ongoing basis.
Implementing a Remote Monitoring System
Remote monitoring with alarm notification is an ideal method to verify that indoor conditions are maintained so personnel can respond quickly, if necessary, to a loss of conditions. It also alerts the team when an unforeseen event such as a storm, vandalism or pipe break takes a building out of specification.
Some systems allow building owners and managers to conveniently monitor and configure the operation of temporary dehumidification, cooling and heating equipment remotely via a secure website. Several other environmental components such as dew point, ambient temperature, surface temperature and relative humidity can be monitored. The technology's flexibility allows customers to set desired parameters to cycle the equipment on and off to maintain and verify ideal conditions, using the least amount of energy.
These systems record climate control conditions on an onboard memory chip and transmits those conditions to a secure website hourly. Alert messages are completely customizable, allowing the user to choose whether alert messages are delivered via text message, email or to websites.
In addition to remote monitoring, it is critical to conduct site visits periodically to ensure equipment is running correctly and to inspect the facility. This hands-on approach further confirms the building is safe from the elements.
Until the economy rebounds, a number of construction projects across the country will be placed on hold. Temporary dehumidification is an essential ally to help construction firms, building developers and others preserve these structures until construction can proceed once again.
Understand the Insurance Implications
Insurance companies have restrictions or exclusions on general liability and umbrella/excess policies that remove coverage for pollution liability. Claims that involve mold or mildew are typically covered under the pollution liability coverage form. Most contractors will procure Contractor's Pollution Liability (CPL) under a separate coverage placement. Mold is an option, for an additional premium, which would be covered under that CPL program. These policies are usually insured under a claims-made coverage trigger, although some insurers are offering this coverage under a typical occurrence trigger form.
There are no exclusions under the CPL that would prevent coverage from applying, except for the "intentional act" provision, which could be difficult to assert by the insurance company. Obviously, it is important to the contractor that the project envelope is secured regarding the CPL as all policies have deductibles or self insured retentions (SIR) that will also be triggered in the event of claims. It is important to remember that the SIR will apply per claim.
What can you do?
Communication is important between the contractor and the underwriter, particularly in situations whereby projects are under suspension or on pause. Such communication can be helpful in determining the risk-management protocols to be installed to prevent claims and responsibilities for self insured retentions (SIRs) by the contractor.
A contractor may wish to have a third party inspection performed on a project under suspension to memorialize the project conditions at the time of pause. Additionally, contract terms and conditions may need to be modified between the contractor and owner to allocate responsibility for claims during such events.
Construction Business Owner, December 2010
