*This article was prepared for publication in the March/April 2023 issue of BIC Magazine.
Dealing with moisture is inevitable in most locations, but is especially relevant to the oil and gas industry since many locations are in warm, humid, coastal areas where condensation is present. Condensation alone is a reason to consider the safety of steel over concrete in the construction of blast-resistant buildings.
Humidity and rain can cause condensation inside and outside buildings, allowing moisture to seep from the ground. Moisture can come from leaky fixtures or overzealous HVAC units, even in dry areas.
Condensation occurs when warm air comes in contact with cold surfaces, which can be a significant factor in choosing building material. Lumber, for example, retains water efficiently. Concrete can also be highly affected by condensation. It doesn’t take much moisture to penetrate concrete, pushing apart the grains and affecting strength and durability.
When moisture enters concrete, the concrete expands, deforming the material. It can also cause spalling when concrete cracks, flakes apart or separates from other building materials. The resulting structural damage can be catastrophic.
When moisture condenses and sits on building materials, it can lead to mold growth and other volatile organic compounds. This growth can deteriorate plaster and paint and cause health problems for anyone who works in a damp building. Even in metal buildings, condensation can lead to rust, corrosion, mold growth and indoor air quality reduction.
It is often assumed it will be known if moisture has seeped into a building, but many of the telltale signs are invisible. For example, interstitial condensation occurs within enclosed walls, roofs or floor cavities, leaving a concrete building structurally unsound without occupants knowing about it. For this reason, buildings require inspections and follow-up.
Recent high-profile events have revealed the danger of reinforced concrete buildings and uncontrolled condensation; this is just one reason why a structure designed to be blast resistant should be built using a material like steel.
Sadly, the world has seen how much damage moisture condensation can do to a reinforced concrete building. Consider the collapse of the Champlain Towers South apartment complex in Surfside, Florida, near Miami, which collapsed in early 2021. Tragically, 98 people lost their lives.
Evidence suggests that moisture from the structure’s pool penetrated the concrete and corroded the rebar meant to reinforce it. There are also records showing that a consultant found significant structural damage to the concrete slab below the pool deck, and cracking and crumbling of the columns, beams and walls of the parking garage in 2018. A memo noted water seeping up “from the underground as a result of storm surge.”
Furthermore, even waterproof concrete does not last forever. At Champlain Towers South, a core sample of the concrete taken in 2020 showed no signs of the original waterproofing and found the concrete was crumbling away from the steel rebar meant to strengthen it.
Of course, reinforced concrete is a common building material used for blast-resistant building design, so it’s understandable to be concerned that moisture might affect a building’s ability to protect occupants, at a minimum.
Construction activities were taking place next door to the Surfside complex, resulting in vibrations. If the vibrations were indeed a contributing factor in the collapse, that is still far less pressure than a blast-resistant building would be expected to handle.
Since concrete can fail on its own due to condensation, even without a blast, steel is the safer alternative.
While all buildings can potentially have condensation issues, there are steps a reliable company should take to ensure a steel blast-resistant building maintains its integrity.
- Adding proper insulation to regulate internal temperature
- The installation of vapor barriers and interior ventilation
- Checking the concrete foundation for potential problems before the building is placed on top
A good building company can save lives. Take the time to carefully select a trustworthy company with on-site services such as risk assessments and long-term service agreements.
For more information, visit RedGuard online or call (855) 733-4827.