- THE MAGAZINE
How long has it been since you took your last water restoration class? Two years? Five years? Longer? We’ve talked to dozens of people over the years who assume that, “I went to water class a couple of years ago, so I remember everything I need to know.”
With all the changes in technologies and standards in water restoration, that’s a very dangerous assumption.
Over the years that we have been in the cleaning and restoration industry, we have been fortunate to learn from some of the very best in the industry. And even though most of what they teach is quite similar, it’s how they teach it that makes the difference.
Most people in this industry have been to one or two water restoration classes, and they assume they have mastered the concepts. But we often receive calls from restorers struggling with fairly simple questions. Sometimes, these calls come from people who have completed an ASD course, attended the Vortex Drying School, or both.
We’ve come to the conclusion that once isn’t enough to pick up all the information presented in these classes. You can always pick up new information if you come to a class with an open mind, ready to learn. And as instructors, we can truthfully say that we have also learned something at every single class we’ve taught or participated in. And between the two of us, we’ve been to more than 200 classes.
The information taught at the advanced schools is for the most part college-level material. Are we to expected to learn, understand, and retain college information in 3 or 4 days? It takes college students months to learn this material. Don’t be hard on yourself or your employees if they don’t grasp everything the first time; we didn’t. It can take two, three, four or more times for these concepts to sink in. Think about this: it’s impossible to outperform our knowledge, but how many of us truly know what our knowledge is without it being tested?
To that end, here is a quiz to see if you’re up to date on what you should know from your water classes. If you can’t answer 80 percent of these questions correctly, it’s time to go back to class.
Introductory Class QuestionsYou should be able to answer these questions if you understand the material from a basic water restoration class.
- On a Class 2 water loss using 100-pint, low-grain refrigerant dehumidifiers, how many dehumidifiers would be required for a 10,000-cubic-foot structure?
- What is the best way to prevent microbial contamination on a clean water loss?
- If a structure is 70° F and 77 GPP, what would the relative humidity be?
- If a window has a surface temperature of 50° F and is exposed to air at 70° F and 77 GPP, would it have condensation on it?
- What is the term that describes the ability for water vapor to travel through a solid material?
- At the beginning of a Class 2 water loss, would you get better drying at 70, 80, or 90 degrees?
- What is the easiest and fastest way to remove water from any structure on any water damage?
- On day 2, what should the GPP and the relative humidity be in the affected area?
- Approximately how high can water wick up a piece of drywall in 24 hours? Why is this important to know?
- When checking to see if you made progress in drying the walls, where do you always check first?
Advanced Class Questions:You should be able to answer these questions if you understand the material from an advanced water restoration class.
- In a water-damaged structure which is 40-by-50-by-10 feet, the wicking in the walls is 6 inches, and wet carpet is being dried in place, how many 350-CFM desiccant dehumidifiers would be required?
- What is the best way to ensure that a water job has been completed?
- A project manager sets up equipment that uses a total of 40 amps of electricity at 115 volts. How many BTUs of heat would be produced by this equipment?
- A two story structure has a sewage loss (Category 3) on the second floor. The water runs through the ceiling, into the walls and across the carpet of the first floor. After initial services and demolition, what class of loss would the first floor be?
- A project manager sets up containment in the structure shown here (Image 1). Taking into account the HVAC setup in the structure, would the pressure in area “A” be positive, negative or neutral when the HVAC system is running?
- You have a house with a crawlspace. The readings in the crawl are 45 degrees and 50% RH, while the affected area is 80 degrees and 30% RH. You are having a problem getting the subfloor dry. You are currently drying with LGRs and centrifugal air movers using “in-place” drying methods. The forecast for the next few days are highs in the 30s and low humidity. What makes the most sense to help speed up the drying of the subfloor?
- If a material is wet and its temperature is at or below dew-point temperature, what must happen for that material to dry out?
- Explain why LGRs dry structures faster than conventional dehumidifiers.
- You have a Class 2 water loss affecting the entire interior of a ranch-style house. Temperature outside is 84 degrees. You set up four LGRs and 34 “low amp” air movers, but your humidity is just not dropping. What could you do to the dehumidifiers to improve their ability to remove water?
- You have a 1,000-square-foot farm house that is totally flooded. The house has no furnace and no power. Outside, it’s 20 degrees and 35% RH. Inside, it’s 45 degrees and 65% RH. You have a 60 kW generator at your disposal. Your three options to dry this structure are:
- Low-grain refrigerant dehumidifiers
- 85,000-BTU indirect-fired furnace
- 3,000-CFM diesel-fired desiccant
Answers:Intro Class Answers:
- 2 dehumidifiers
- Dry the structure
- 70% RH
- Physical extraction
- Less than 65 gpp less than 40% RH
- 8” per day, indicates how long the water has truly been in the structure
- In front of the air movers
- 2 Desiccant dehumidifiers
- To ensure that all affected materials have reached pre-determined drying goals
- 15,640 BTUs
- Class 1 (because all wet porous materials must be removed)
- Heat the crawlspace
- Must increase in temperature
- Simply stated, they bring the air vapor pressure lower, thus increasing the difference between the wet material’s vapor pressure and the dry air. They also have twice the moisture evaporation rate potential (MERP)
- Properly feed the dehumidifiers with cool air from the structure’s HVAC system
- Use the indirect fired furnace because the outside air is very dry. The desiccant is too large for this job.