Preparing for El Niño during Construction
by Bruce S. White, Vice-President
AMERICAN ENVIRONMENTAL SPECIALISTS, INC.
The weather reports all say the same thing; “this may be the biggest El Niño we’ve seen since….” With weather predictions all clearly indicating this to be in our immediate future, we have to ask the question of, “Are you prepared to deal with it during your construction?” If the answer is yes, then forget this article and move onto something else. If your answer is “maybe”, “not sure”, “I don’t know”, or “hmmm… what should I prepare for?”, then you need to read on!
What we’re really talking about, in general, is water. Water entering a building during certain aspects of construction, may or may not cause you problems. However, at some point, you’re going to have to deal with the water one way or the other. So let’s talk about what you can do, what you should do, and what you better not do!
During initial construction of the foundation and framing of structure water in the form of rain, will not pose much of an issue. While metal framing (columns & beams) may end up with some slight corrosion, it will not impact the integrity of the structure long term. When rain or moisture may impact the columns and beams is after fireproofing has been applied, and that moisture becomes trapped somehow (curtain walls, EIFS, drywall). When this occurs, we now have water in two forms, liquid and vapor. The trapped moisture in both forms may set the fireproofing up for fungal amplification as well as the interstitial sides of the curtain walls, EFIS, and/or drywall.
Smaller commercial construction may consist of wood framing, composite wood components, or other semi-organic materials. When these items are introduce to moisture, in the form of rain, it may take some time for them to be properly dried prior to the continuation of construction. Often times, due to time constraints and scheduled trades, this does not occur and later down the building road, sets the contractor up for a costly construction defect loss. Issues like this occur mostly in low rise commercial sites, multi-unit housing, and single family housing.
What can a contractor do in both of these situations? The quick and easy answer is referred to as Moisture Mapping. “Moisture Mapping is the predetermined method whereby the affected areas of a structure are evaluated for moisture content within the Built Environment”. Moisture Mapping takes several forms and layers, including photo documentation, relative humidity readings, surface testing for moisture burden in construction materials and thermal imaging. All of these methods help “paint a picture” of the overall moisture burden within the structure, and help determine what methods can be introduced to rectify the situation, or confirm the construction process can continue uninterrupted. More to the point, it helps protect the General Contractor, and sub-trades from costly litigation downstream, or limit liability based upon the findings.
What happens if there is an issue of moisture burden in that structure? Several things can be done, and all of it is focused on removing the moisture, either physically, or employing mechanical techniques commonly referred to dehumidification. Let’s take an example AES worked on recently in the Southern California area.
A high rise facility involving new construction was well underway. A tower crane was mounted for material supply in a vertical portion of the building open to the outdoor environment. Similarly construction hoists were mounted on two sides of the high rise to allow for trades to gain access as well as material hoisting to the various floors. The roof was 80% in place; however vertical shafts had not been enclosed. The curtain walls were in place with the exception of where the hoists were mounted at each floor. MEP was being installed as each floor was poured cured. Architectural finishes including drywall, insulation, and other pre-manufactured items were being installed from the basement up several floors. Torrential rains dropped more than two inches of rain over a twenty four hour period. The moisture entered the buildings through vertical shafts, stairwells, elevator shafts, curtain walls and roof drains not yet completed. Moisture Mapping indicated varying levels of materials impacted by the moisture intrusion including wet fireproofing, exterior curtain wall insulation, drywall, duct board, firewall board in vertical shafts, mechanical insulation, thermal pipe insulation and stockpiled materials. This was the “perfect storm” and nightmare for not only the General Contractor and sub-trades, but the building owner as well. American Environmental Specialists utilizing experience and knowledge in this area, consulted with the General Contractor and developed specific plans and protocols to follow to remedy the situation; timely and effectively. They directed the Contractor to various resources, technologies and specialty firms to coordinate a precise moisture remediation plan, thus minimizing downtime, latent moisture effects, and continue with schedule of construction.
Who should Contractors Contact Now before an issue arises? You may have heard the term “catastrophe planning”, or “incident planning”, or “emergency planning” used in other industries. For AES, we use the term “Construction Incident Planning” (CIP). Construction Incident Planning is a method whereby historically recorded moisture intrusion issues in construction, over multiple types/events, provide a mechanism to address and plan for an occurrence”. CIP involves a general discussion primarily with the GC, Environmental Consultant, to look at how the construction will take place, prior to, during, and following construction. Together they identify equipment, materials, and specialty trades to include in a Construction Incident ‘roll out”. AES refers to this as the CIProTM. It identifies companies, individuals within that company, contact numbers (including after hours), schedule of rates (labor, equipment, and materials), responsibilities of each party, incident coordinator, and intended events.
What types of events can be included in the AES CIProTM.? There are multiple events that can take place in a building besides, but including moisture intrusion. They include, but are not limited to:
- Broken Pipes
- Hydrostatic Release
- Sprinkler System Discharge
- Curtain Wall disintegration
- Interior damaged materials
- Debris outside construction perimeter
- Latent release
- Employee/Occupant Injury
- Employee/Occupant/Mass Casualty
- Fungal Amplification
- Catastrophic Response
- Near Miss
- Incident Investigation
- Root Cause Analysis
- Exposure Monitoring (Silica, Lead, Asbestos, Bacterial, Toxins, Gases)
- Environmental Monitoring
- Fugitive Dusts
- Respirable Silica
- Temp & Rh
Any or specific items can be addressed in the plan and tailored to the client needs. AES normally finds the items of largest concern are moisture, plumbing, fungal amplification and environmental monitoring are addressed as primary concerns, and depending on the type of construction, or the client, others are additions to the basic request.
For any additional information, and informative educational presentation on CIP/CIProTM, you can contact Jim McClung or Bruce White at 714-379-3333.