Removing Moisture from Materials
The rate at which moisture moves through materials depends upon two primary factors: the type of material affected and the degree of wetness. The type of material affected will vary in permeability (ability for water to pass through the material), hygroscopicity (ability to absorb water), thickness, density, temperature and "R" factor (resistance to heat transfer).
Each of these characteristics will influence the way in which water travel through the material. The degree of wetness will influence the moisture movement, in combination with other material characteristics, by indicating the type of water being addressed. Water will be present in one, two or three forms:
- Surface Water
- Free Water
- Bound Water
Surface water is readily available at the surface of a material. It is liquid, visible and will evaporate readily. All materials are capable of supporting surface water. Surface water is best removed physically using mechanical extraction equipment or other physical means. Minute amounts of remaining surface water are readily evaporated using large amounts of airflow and moderate temperature and humidity.
Free water is present within a material but is not bonded. It exists in cavities, open pores and other air spaces within the material. It is liquid, generally visible by a darkening of the material (e.g., wood) and can evaporate readily. Most materials are capable of supporting (containing) free water. Materials not capable of retaining measurable amounts of free water are non-permeable, non-porous materials such as vinyl, vinyl composite, steel, rubber and some other solid, synthetic materials.
Bound water is absorbed by the material and held captive by chemical bonds. It is similar to vapor in that it is not fluid, yet similar to a solid/liquid in that it is bonded to other molecules. Because it is bound to other molecules, it must first be freed before it can be removed.
Respiratory Protection from Mold
The human body can be exposed to contamination in three ways: by dermal (skin contact), inhalation (respiratory) and ingestion (consumed). The most common way of providing protection is the use of personal protection equipment. One such piece of equipment is a respirator. Respirators come in a variety of styles, with different levels of protection, and are rated according to their protection factor.
Before using a respirator, all of our technicians will receive effective training on respirator usage. According to OSHA's "General Duty Clause," an employer is required to provide a safe work place for employees. Thus any company doing microbial remediation would have to provide a respirator-training program that would include medical evaluations. In this training our technicians are trained how to put on and take of a respirator, how to care for their respirator, what a respirator will and will not protect against. There are additional requirements for wearing a respirator that include a medical evaluation of the technician's lung capacity and a fit test to assure protection.
For microbial remediation work that is performed by technicians, the cartridge almost always used is a HEPA filter. A HEPA (High Efficiency Particulate Air) fliter removes 99.97% of particulates down to 0.3 micrometers. With this level of protection, virtually 100% of mold spores will be filtered out and not enter the lungs.
Two Drying Methods
After making the decision of whether or not to dry a material, Project managers begin evaluating how to begin the restoration work. Many methods are available - each applying a different combination of humidity control, temperature, airflow and physical manipulation of the material (e.g., injection of airflow, perforation, removing finish materials).
Our Project Managers use the information obtained during evaluation of materials to help select the best drying method for the job. Generally there are two primary methods to promote drying of affected structures: 1) disruptive methods and 2) aggressive methods.
Disruptive Drying Methods
Disruptive drying methods involve removing wet items, injecting air to speed drying, or perforating surfaces to allow water to evaporate. The term disruptive is used because repairs will have to be done after the structure has been dried. Use disruptive methods when contamination, damage, cost or customer concerns require removal or manipulation of the affected material.
Aggressive Drying Methods
Aggressive or "in-place" drying methods involve leaving wet items in the structure and drying them in-place using warm, dry direct airflow. Aggressive methods are used when contamination and damage are not concerns, and when it is cost effective to dry an item instead of replacing it.
Project Managers will use aggressive drying methods when all of the following are true:
- The water intrusion came from a sanitary source (Category 1).
- Drying carpet and underlay (pad, cushion) in place will not cause structural damage to subfloor (especially hardwood).
- Adequate dehumidification is available and usable on site.
- Deep extraction tools are available.
The success of each decision made during the restorative drying process depends on the information upon which the decision was based. A skilled technician with quality meters will make the proper decision at each phase of the project.
HVAC Systems: Affected by a Fire
HVAC systems condition the air within occupied interior spaces. They ventilate and supply warm or cool air through an air conveyance systems referred to as ductwork. HVAC systems typically have a cold side, or return air, and a hot side, the supply air. An air filter system is normally strategically located on the return side, somewhere before the blower motor compartment. Most air filters are engineered to capture smaller airborne contaminants in order to protect the blower compartment components.
Although HVAC systems all have the same purpose, they vary greatly in design. Soot and smoke odor removal is relatively easy in some types, especially metal ducts. However, following a structural fire, soot contaminates coat most interior fiberglass surfaces. Fiberglass duct insulation is easily contaminated due to the volume of air spaces within the insulation matting. When ducting becomes exposed to smoke odor gases and particulates, PICs penetrate deep within the fiberglass fibers used to insulate the ducting. An HVAC system that was operating during a fire will certainly be more heavily contaminated than one that was turned off; however, systems become contaminated even when they were not operating during the fire.
An inspection of the HVAC system will determine when the complete system requires cleaning. In heavy soot contamination situations, restorable mechanical components within the HVAC system should be disassembled, cleaned and deodorized in accordance with published NADCA standards. NADCA stand for National Air Duct Cleaners Association.
What is Microbial Contamination?
What is Microbial Contamination? Where does mold come from? Is microbial contamination a health concern issue? How do you properly get rid of a microbial contamination?
Microbial contamination refers to a variety of microorganisms, including mold, bacteria, viruses and protozoa; and fungi, which includes molds, yeasts, and their by products and toxins. All of these can affect the health of a building and its occupants.
As a starting point the proper job sequencing for a typical microbial-remediation project includes but it not limited to: identifying and stopping the source of moisture; setting up containment; establishing negative air; removing contaminated building materials; cleaning surfaces; drying the affected areas; conducting a post remediation evaluation.
Mold spores are a major concern for our project managers. Because of their very small size, mold spores can be anywhere there is air, including under carpet, inside wall cavities, under kitchen cabinets, virtually everywhere. Molds are usually not a problem unless mold spores land on a damp spot and begin growing. They digest whatever organic material they grow on in order to survive. Some molds grow on wood, paper, carpet, foods and insulation, while other molds feast on the everyday dust and dirt that gather in the moist regions of a building. Generally mold spores are hydrophobic. This means that spores do not like water itself. While mold spores need water to colonize (germinate and grow), they like wet organic substances, not a puddle of standing water.
Hazard Awareness and Risk Assessment
The first line of defense against safety hazards is awareness. A hazard inspection checks for any work-site situation that potentially poses danger to life or property. Project managers must then perform a risk assessment on all potential hazards found on the work site. The assessment evaluates the risk or likelihood a particular hazard will cause harm. Due to the unsafe nature of most water damaged structures, hazard inspections and risk assessments are essential for protecting workers.
The initial hazard inspection and risk assessment of a water damaged facility would involve three important aspects. The first step is to identify hazards that could give reason not to enter the building, such as wet electrical panels and collapsing ceilings. The second step is to identify the presence of regulated building materials such as asbestos, lead or PCB's (polychlorinated biphenyls). Government-regulated substances may require testing or inspection services from specialized. Third-party experts to assess health and safety issues. Finally, a competent technician conducts a risk assessment and installs or implements the necessary hazard controls for any identified hazards.
Installation of Air Movers
Air movers specifically distributed to ensure proper distribution of air.
Air movers are placed in the environment to ensure rapid evaporation across all affected surfaces. The number of air movers necessary depends upon the number of wet surfaces, the amount of water present, and the ability for air to reach each wet material (e.g., wall cavities, behind cabinets, and under contents).
The IICRC S500 Standard recommends that air mover installation quantities should be based on the amount of wet surface area in affected spaces. For the initial phases of drying, air movers should produce continuous airflow across affected material surfaces. A step-by-step process for determining the proper number of air movers is:
- Place one air mover for each affected area.
- Add one air mover for every 50 to 70 sqft. of affected floor area.
- Add one air mover for every 100 to 150 sqft. of affected wall surfaces (above 2') and ceiling surfaces.
- Add one air mover for every room offset or inset greater than 18 inches.
This calculation should provide an appropriate amount of air movement for most water intrusions, but can vary depending of the situation and type of materials affected.
Once the number of air movers to be installed has been determined, several factors will influence their actual placement. These factors include: the type of material affected, the degree of saturation, the accessibility of the actual wet surface, power availability and equipment availability. Below are some general guidelines for installation of air movers:
- Air movers are directed toward the wall at a 5 to 45 degree angle, depending on the type of air mover.
- The air mover's snout will almost touch the wall, within in 1 to 2 inches.
- All air movers in each area will face the same direction to ensure that air movers are not pushing against each other.
- When placing air movers, we need to consider the need for circulation throughout the affected area.
- Specialty air movers may be necessary if building cavities require air flow.
Water Damage following a Fire
After a secure building by properly completing a board-up, water removal and drying wet surfaces is the next step. Due to the presence of water, fire restoration and water restorations are related. All of the primary and secondary challenges associated with water restoration can be found in a fire restoration project. Examples are degradation of structural components, contents, corrosion of metallic surfaces and microbial growth. An added complication is that waterborne smoke odor may penetrate deeply into porous materials.
In locations where water has been used to extinguish the fire, the water will migrate through the structures and wet building materials. During this process, the water becomes contaminated with innumerable materials. Excess standing water should be extracted thoroughly. Some buildings are so full of water that special pumps are required to remove standing water. Where possible, wet surfaces should be treated with a broad spectrum, government-registered disinfectant to control the growth of microorganisms. All personnel should followed label instructions when using EPA-registered products.
Dehumidification is set-up within the water damaged area(s) depending upon power availability and the type of drying equipment available. A supplemental electrical power source may be necessary in some buildings.
What is lurking in flood waters?
Underneath the surface of flood waters can be an abundance of danger: both living and non-living. The Environmental Protection Agency requests that everyone limit their exposure to flood waters. The agency states that flood waters may have high levels of raw sewage from both humans and animals embedded in the waters. In addition to that, many plants, factories, and farms may be overrun with flood waters, and some of those can leak toxic materials into the water, such as an oil refinery or nuclear plant. These issues can affect water mains, well water, and lines that can bring contaminated water into dry homes that may not even be flooded.
Unwanted animals may be lurking underneath the waters as well: crocodiles, snakes, fire ants, and even, if you're along a coastline, sharks.
On top of that, mold and standing water can both lead to unwanted visitors inside your home. Mosquitoes and insects tend to live, breed, and thrive in standing water, and mold growth can spike in the event of moisture. Getting rid of standing water near your home, in gutters, old tires, plastic covers tarps, pools, and buckets can certainly help.
While we can't totally alleviate the effects of flooding during severe weather, developing a flood plan for your family can help out.
Create a barrier of protection for areas that can be inundated with floodwaters, by way of perhaps sandbags. Additionally, secure food and water for your family in the event that clean, drinking water is scarce.
Officials urge storing in a cool place, at least 3 days of water for each individual person. Do not use or drink contaminated water for anything: brushing your teeth, washing dishes, making ice, or preparing food.
After the Storm, keep older and younger people with sensitive immune systems out of the home until your home or business can be restored by SERVPRO of Fenton/South Ballwin. We are here to help 24/7/365. 314-858-1688
Mitigation services help prevent additional damages. Loss mitigation services include winterization to prevent freezing, controlling corrosion, and cleaning surfaces to prevent staining.
As soot combines with atmospheric water vapor, it becomes acidic. Neutralization of acid smoke residue is a fundamental part of the initial stages of corrosion prevention. In most cases, alkaline solutions are used to help remove and neutralize the acid smoke residue.
After removing the smoke residue from metallic and plastic laminate surfaces, apply an oil-based coating (Many restoration professionals use a common lubricant like WD-40). This treatment will slow down and/or inhibit corrosion and discoloration by airborne smoke particles that remain after the Project Manger completes the emergency service visit. This simple, but often overlooked, step can help to reduce overall replacement costs.