Quick, Low-Cost Water Dry-Out Techniques for Schools & Commercial Buildings Under Construction Case Study #3 Duration: 1-2 hours

Transcription

1 Quick, Low-Cost Water Dry-Out Techniques for Schools & Commercial Buildings Under Construction Case Study #3 Duration: 1-2 hours USGBC Professional Development Course EPP

2 Case Study #3 Introduction Flood caused by worker sabotage on the 27 th floor of a residential high rise under construction. Plastic bag was stuffed into toilet. Water ran down to the 19 th floor. Some kitchen cabinets wet. Instead of using wet vacs to remove water from floors, plywood ramps were quickly built and pushed against slider door stops, and water was swept out of the units onto patios. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 2

3 Case Study #3 Introduction This procedure was very fast and cheap. And did not have to wait until professional dry out guys arrived. The faster the bulk of the water is removed, the sooner you can start to dry out walls and cabinets. A major difference between this case study and the two prior studies was that the walls behind the wet kitchens were accessible from the rear. Drywall was cut from walls behind kitchen cabinets. No insulation. Easily dried. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 3

4 Case Study #3 Introduction No Dehu s No IR cameras. Minimal use of moisture meters. No wet vacs. No fans. No water mitigation contractors. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 4

5 Objectives: Case Study #3 After completing this case study, the student will be able to: Explain why neither specialized drying equipment nor specialized testing equipment is always needed if the water is quickly removed, and wet walls are cut open to facilitate drying. Describe how disinfectant use can eliminate mold problems, and reduce the cost of drying. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 5

6 Outline: Case Study #3 Using disinfectan to eliminate mold problems, and reduce the cost of drying. Techniques to expedite water removal and drying out a building without specialized equipment, and without extensive testing or specialized equipment like infrared cameras or laser thermometers. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 6

7 Using Disinfectant When there is a flood that includes contaminated water, it is a widely accepted industry practice to spray with disinfectan to keep down the growth of bacterial contaminants before doing the clean-up. This is excellent advice, and should also be followed when there are floods from clean water. Why? It is very inexpensive, and because it not only keeps down the growth of bacteria, but minimizes mold growth. Only household disinfectants should be used. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 7

8 Using Disinfectant The optimal approach to dealing with floods during construction is to first spray household disinfectant into the flood waters before drying up all puddles. The disinfectant wicks up into the drywall and cabinets, and limits mold and bacterial growth. Then DRY. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 8

9 Using Disinfectant Many walls were filled with insulation that is slow to dry. Metal track inside walls arrow) (arrow can hold a great deal of water. Spray wall cavities and track with disinfectant. Then DRY. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 9

10 Using Disinfectant Three floors below flood. Water puddles not yet removed on Day 1. Walls marked for removal. Puddles sprayed with disinfectant. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 10

11 Using Disinfectant 2 nd day. Lower floors having drywall and insulation removed. Using moisture meter. Still wet (upper right picture). But no mold. Remember mold takes hours to start to grow, but that 2-3 day rule does not apply to wet walls that have been sprayed with disinfectant, or have soaked up disinfectant. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 11

12 Water Removal and Drying Walls behind all kitchens were accessible. Not insulated. Not on block walls. November time frame. Cool and dry. Water did not wick up very high in walls (upper right picture). Units easily dried without Dehu s, and without extensive monitoring with moisture meters or IR camera. All doors and windows were immediately opened for natural ventilation to facilitate drying. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 12

13 Water Removal and Drying Day 1 of the flood, and all the wet drywall in 2704 had already been removed. Puddles sprayed with disinfectant, and then swept out the door. Floors still moist. Windows and doors open. Cool breeze in all units. Bone dry by tomorrow. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 13

14 Water Removal and Drying Flooding included elevator lobby area. Drywall in front of elevator (yellow arrow) cu to allow drying. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 14

15 Water Removal and Drying Wet drywall in unit below (2604) not yet removed, but marked for removal. Puddles mostly dried up. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 15

16 Water Removal and Drying Ceiling below the clogged toilet needs to be removed and replaced with new (upper left picture). The penetration around the toilet waste line had been sealed with concrete, but because there was a cold joint, it leaked. Cold joints should be sealed with appropriate water proofing to avoid such leaks. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 16

17 Water Removal and Drying No way to soak this material on the ceiling with disinfectant to avoid mold growth. And that's a lot of water, and this ceiling drywall will have lost some of its structural integrity, so you want to replace with new. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 17

18 Water Removal and Drying Checking moist wall for fiberglass insulation. None here. No water wicking up drywall in cavity. No water in metal track. Drywall hung off of the floor. This wall will dry without being cut open. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 18

19 Water Removal and Drying Wet wall with foil-backed vapor barrier on exterior wall. Vapor barrier (insulation) does not absorb much moisture, but will definitely keep wall from quickly drying. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 19

20 Water Removal and Drying 23 rd floor: Electrical room wet, but only at bottom. Easy to dry. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 20

21 Water Removal and Drying This wall, with the elevator call buttons, wet. Marked for removal to aid drying. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 21

22 Water Removal and Drying For some unknown reason, instead of the flood water flowing down the elevator shaft to the pit, the water poured out elevator doors on each floor, and flooded the lobby areas. Most likely there is an open metal track on the inside of the door that is catching water and channeling it out the door frame. Not a good design. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 22

23 Water Removal and Drying This wall with the elevator call buttons is wet in the middle. No way to spray the puddles below with disinfectant, and then take one's time to remove the drywall. Remove ASAP to avoid mold growth. Needs to be opened up to allow drying. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 23

24 Conclusion: Case Study #3 No Dehu s No IR cameras. Minimal use of moisture meters. No wet vacs. No fans. No water mitigation contractors. No mold. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 24

25 Conclusion: Case Study #3 You should now be able to: Explain why neither specialized drying equipment nor specialized testing equipment is always needed if the water is quickly removed, and wet walls are cut open to facilitate drying. Describe how disinfectant use can eliminate mold problems, and reduce the cost of drying. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 25

26 Summary: Case Study #3 Why so different from Case Studies 1 & 2? Kitchen cabinets were on walls that could be opened from the rear, and could be quickly dried by natural ventilation. Fewer wet cabinets. Disinfectant immediately sprayed into puddles, allowing disinfectant to wick up into walls and cabinets before dry-out. Drywall was cut very quickly. Flood occurred in November. Not in hot, humid summer months. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 26

27 Summary: Case Study #3 During construction, it is generally cheaper to cut open drywall to facilitate drying, than to rely on water mitigation contractors. When the walls are open, they can be sprayed or fogged with disinfectant. And they can be visually inspected for mold. Sampling is NOT a good substitute for a visual inspection for mold. When walls behind cabinets cannot be opened to dry/inspect, there are no simple solutions. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 27

28 Case Study #3 Review Quiz 1. Why was this flood mitigation low tech (no IR camera, no dehu s)? a. Builder did not want to spend the money. b. Response was very quick and it was easy to tell what was wet and what was not wet. Special equipment was not needed. 2. Why were Dehumidifiers not used? a. Walls that needed to be dried out were all accessible, and easily cut open and dried. b. Flood occurred in November when it was cool and relatively dry. Natural ventilation was sufficient to dry. c. Most of the water damage occurred to walls, and not cabinets. d. All of the above. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 28

29 Case Study #3 Review Quiz 3. Foil backed (vapor barrier) insulation on external walls does not make dry-out any harder, because it does not absorb water like fiberglass insulation does. a. That s right. Drying exterior walls is easy without removing the foil backed insulation. b. No. These vapor barriers or moisture retarders do make it harder to dry exterior walls. 4. For this flood, the reason that the puddles were so quickly removed from the units was that the builder had access to many wet vac s. a. Correct. An excellent water mitigation contractor was brought in to quickly wet vac the standing water. b. No. Wet vac s were not used. Plywood ramps were quickly built that allowed water to be swept out the sliders onto the patios. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 29

30 Case Study #3 Review Quiz 5. Why was this case so different from the earlier flood? (Select all correct answers.) a. Cabinets were on walls that could be opened from the rear, and quickly dried by natural ventilation. b. Fewer wet cabinets. c. Drywall was cut quickly. d. Flood occurred in November, not in hot, humid summer months. e. Disinfectant was immediately sprayed into puddles, allowing disinfectant to wick up into walls and cabinets before dry-out. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 30

31 Case Study #3 Answers to Review Quiz Check your answers against the correct ones below. If you answered more than 1 incorrectly, please review the case study and take the quiz again. 1. b 2. d 3. b 4. b 5. a, b, c, e, d Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 31

32 Conclusion: Case Study #3 This completes the 3rd (and final) Case Study. We hope you have found this free on-line course material useful. Our web site at has other free online courses. Please check it out when you have time. If you have any comments or suggestions, please them to: Green-Buildings.org The next page explains how you can obtain a Certificate of Completion. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 32

33 Conclusion: Case Study #3 After passing this last review quiz, if you would like to receive a Certificate of Course Completion, please send a check for $25 payable to: Certified Mold & Allergen Free Corp W Lake Vista Circle Davie, FL Please include your name, address and the course name. Your signature on the check is your affidavit that you have completed the entire course, and answered at least 80% of the review questions correctly. To help us maintain and improve the quality of our online courses, kindly take a few minutes and fill out the Course Evaluation form (course EPP ), and it to us. Dry-Out Techniques Copyright (c) 2008 by Certified Mold & Allergen Free Corp. Case Study #3, page 33