Water in Buildings: Chemical-Free Clean Up & Resotration for Builders & Facility Managers Case Study #2 Duration: 4-6 hours USGBC Professional Development Course EPP0002-002
Case Study #2 Course Outline Case Study #2: Drying out a building under construction immediately after flooding. Locating and drying wet areas under and behind kitchen and bathroom cabinets. Day 1 (1-2 hours): Identifying water damaged drywall and cabinets. Removing standing water quickly. Finding insulation inside walls. Cutting wet walls open to speed drying. Day 2 (1-2 hours): Verifying that building is drying out and dehumidifying equipment is working properly. Additional cutting of walls to help dry-out. Day 3 (1-2 hours): Ducting dehumidified air into walls and behind cabinets. Removal and replacement of cabinets where necessary. Preventing mold growth by fogging or spraying with disinfectant. page 2
Case Study #2 Introduction This case study involves a mid-rise residential building under construction. Cabinets and bathrooms were installed in flooded areas. A pipe leaked in the ceiling of Unit 604, and flooded many units on the 6 th floor, as well as the 5 th floor. We were called within 24 hours of the flood. When we arrived, a water mitigation crew had been brought in to wet vac the floors, and to supply fans and dehumidifiers as needed. page 3
Case Study #2 Introduction This was a complicated and difficult flood, as high-end kitchens and bath cabinets were flooded. Fortunately, most of the cabinets were installed off of the floor. But the walls behind were often wet, and these walls were, in many cases, block walls with fiberglass sound-proofing between the block and the drywall behind the cabinets. We did not use an infrared camera. It was obvious where the water was, because we were brought in within 24 hours, and the floors were still wet. page 4
Case Study #2 Introduction As we stated at the beginning of Case Study #1 mold generally will start to grow in 48-72 hours if water is not dried up. It is therefore prudent to dry the building as quickly as possible. Your job is to understand the work that is being done. But also to consider any limitations to the methods applied, and how YOU would respond to a similar water event with your local resources and differing conditions. Mold growing under cabinet page 5
Case Study #2 We will now begin with Day 1 of the 3 days. page 6
Objectives: Case Study #2, Day 1 After completing this module, the student will be able to: Explain the importance of knowing what type of insulation is in the walls, and how this effects drying. Explain why air drying or drying with fans is not enough, and that you must sweep or wet vac the flooded units first. Explain why some walls are more complicated to dry than others. page 7
Outline: Case Study #2, Day 1 Visual inspection. No infrared camera is used. Removing bulk water by sweeping and/or vacuuming. Opening wall cavities and removing cabinet toe kicks and baseboard to allow quick drying. Identifying the insulation inside walls which may be hard to dry. List areas that will not naturally dry in 48-72 hours, and recommend where dehumidifiers be used to facilitate drying. Wall behind kitchen cabinet opened from other side page 8
Day 1 Inspection: Visual Unit 604: The flood was caused by a leaking AC condensate line pipe in the ceiling of Unit 604. About 20 units on the 6 th and 5 th floors were flooded. page 9
Day 1 Inspection: Visual Upper right picture shows water-damaged outside hallway ceiling. The can of red marking spray paint only worked well when inverted. So marking ceilings was not easy. The main picture shows a water-damaged interior soffit (dropped ceiling area at edges of room.). page 10
Day 1 Inspection: Visual Upper right picture: AC closet with air handler in place. The builder did not want to remove the air handlers, so drywall was cut all around the outside of the closets, and dehumidifiers were to be installed to quickly dry closet interiors. Main picture: Typical kitchen island. Floor still wet. Infrared camera not needed to determine where wet drywall will be located. Drywall behind will be cut along yellow line. Yellow arrow points to drywall hung off of the floor, but drywall still needs to be cu to make sure cabinets behind are quickly dried. page 11
Day 1 Inspection: Visual Ceiling wet around light over shower. Ceiling must be removed, and replaced with new material if not dry in 48 to 72 hours. In order to make this determination as to dry, you will need a moisture meter. page 12
Day 1 Inspection: Visual Water-damaged bathroom cabinet. Remove and replace with new. page 13
Day 1 Inspection: Visual Elevator shaft was flooded. page 14
Day 1 Removing Bulk Water Drying out the units. Sweeping and vacuuming water from the units is 1000 times faster than evaporation. All of the standing water was quickly removed from the units within 24 hours by sweeping it out the door or vacuuming. page 15
Day 1 - Open Walls, Remove Toe Kicks and Baseboard Main picture: Kitchen cabinets are set off of the floor. Yellow arrow points to spacer between cabinet and drywall that is up against a wet wall. Upper right picture: Remove all toe kicks under cabinets to facilitate drying. Toe kick was sitting on the floor, and became wet and discolored. Discard. page 16
Day 1 - Open Walls, Remove Toe Kicks and Baseboard Upper left picture shows water on floor of AC closet. Most units had air handlers installed in the closets. The task was to dry out these closets without removing the equipment. None of the walls around the air handlers had fiberglass insulation in them. To dry out the AC closets quickly, we put dehumidifiers into each of them. Main picture shows back of baseboard in public hallway that is wet on the bottom. Base board, especially heavy base like this, must be pulled so that walls behind can dry quickly... before mold can grow. page 17
Day 1 - Open Walls, Remove Toe Kicks and Baseboard All the walls needing to be cut open were marked with red paint, based on where there was water on the floor. Several thousand linear feet of walls were removed mostly at the bottoms of the walls. Infrared camera not need to determine extent of water as the floors and walls were still visibly wet. page 18
Day 1 - Open Walls, Remove Toe Kicks and Baseboard Some of the internal doors were removed to make sure the doors stayed open during drying. All others were kept open with wooden blocks. Doors needed to be open to allow proper ventilation for dry-out. page 19
Day 1 - Open Walls, Remove Toe Kicks and Baseboard Upper left picture: Indicated on the door of each unit was how many dehumidifiers were needed, and where they should be placed. Main picture: All walls with standing water underneath were cut open to facilitate drying. Infrared camera not needed here as it was obvious which walls got wet. page 20
Day 1 - Open Walls, Remove Toe Kicks and Baseboard Bathroom behind kitchen cabinets. Wall to be opened to help dry out wall behind cabinets. Dehumidifier to be placed in bathroom, and under kitchen cabinets. page 21
Day 1 - Open Walls, Remove Toe Kicks and Baseboard Most water dry-out companies get paid based on the days it takes to dry and the amount of equipment used. They do not want to remove base boards or cut open walls to facilitate quicker drying. In the construction environment, it is much cheaper to open walls and remove baseboards, rather than spending the extra time to dry out. In any event, you never really know if the inside is dry or not until you cut the walls open. So you might as well cut them open to begin with. page 22
Day 1 - Identify Insulation Main picture: Some of the walls had fiberglass insulation in them, which is very slow to dry. Walls separating units and hallways were concrete block, insulated with fiberglass soundproofing, and with a single layer of drywall on them. Insulated walls will not dry quickly unless dehumidifier equipment is used, or the insulation is remove to allow natural drying. Upper right picture: Internal wall with no soundproofing. Easy to dry. page 23
Day 1 Identify Insulation Foil-backed paper insulation inside exterior walls. Easily dried (at least compared to fiberglass insulation). page 24
Day 1 - Identifying Hard-to-Dry Areas Upper left picture shows wet drywall inside of wall cavity behind kitchen island. The bottom metal framing track can hold water for weeks. Walls must be opened and track wet-vac d to facilitate drying. Otherwise very hard to dry. Main picture shows typical kitchen with island (yellow arrow), which is always on a drywallbased (not concrete block) wall. Easy to dry. Blue arrow shows the 2 nd half of the kitchen, which could be on a block wall, or could be on a drywall wall. If on a block wall, the wall behind will be hard to dry. To dry we will need to pump dry air directly into these cavities. page 25
Day 1 - Identify Hard-to-Dry Areas Island is installed up against drywall. There is no spacer at yellow arrow. The wall is wet beside this kitchen island. Ceiling above wet. This area was identified as a hard to dry area which will need cabinets removed in addition to dehumidification to help dry. Wall and ceiling need to be removed. Cabinets on island need to be removed. They cannot be dried in place. page 26
Day 1 - Identifying Hard-to-Dry Areas This picture shows a typical kitchen situation. Kitchen cabinets (yellow arrow) are on a public hallway, which in all cases means behind a block wall, with fiberglass insulation on the inside of the block wall, and on the outside. (Baseboard in the hallway will be pulled out in a few days.) The challenge is how to dry out the wall behind these cabinets, because you cannot cut open the wall behind to aid in drying. This area was identified as a hard to dry area which will need dehumidification to help it to dry. Day 2 we will show you how we did this. page 27
Day 1 - Identifying Hard-to-Dry Areas Drop ceiling over kitchen is wet. Remove ceiling and place exhaust duct from dehu into AC ducting to dry out the ducting in case it got wet. AC ducting in the building is all rigid duct. Easily dried. (Flex duct if the insulation in the exterior gets wet, must be discarded.) page 28
Day 1 - Identifying Hard-to-Dry Areas Upper left picture: Note to place dehu under kitchen cabinet Main picture: Wet soffit. We made a note to fog interior with disinfectant through access panel. page 29
Day 1 - Identifying Hard-to-Dry Areas Main picture: Note to put dehu output under this cabinet on this wall. Upper right picture: Wet under cabinets, but no cabinet material is touching floor. page 30
Conclusion: Case Study #2, Day 1 This concludes Day 1 of Case Study #2. You should now be able to: Explain the importance of knowing what type of insulation is in the walls, and how this effects drying. Explain why air drying or drying with fans is not enough, and that you must sweep or wet vac the flooded units first. Explain why some walls are more complicated to dry than others. Please answer the review questions on the following slides page 31
Case Study #2, Day 1 Review Quiz 1. In this case study, how long was it before we were called in? a. 24 hours b. 72 hours c. 1 week 2. What was the source of water intrusion? a. Roof leak b. Broken water pipe c. Shower pan overflow d. Sabotage 3. How long does it take before mold can start to grow? a. 24 hours b. 5 10 hours c. 48 72 hours d. 10 days page 32
Case Study #2, Day 1 Review Quiz 4. Why should windows be open during building construction? a. To allow the units to ventilate so that super high humidity does not occur, which can cause mold b. To cool the workers c. To allow water in so that builders lose money 5. The Gypsum Industry Association recommends what practices to keep drywall from getting wet. (Select all that apply) a. Protected during transport b. Hung off the floor by 1 inch c. Hung off the floor by at least ¼ inch d. Water in buildings immediately dried up page 33
Case Study #2, Day 1 Review Quiz 6. What complicated the drying process in this case study? a. Cabinets were already installed. b. Walls behind cabinets were oftentimes block walls that could not be opened from the other side to help drying. c. Wet walls often had fiberglass soundproofing insulation in them that made drying much more difficult. d. All of the above. 7. In this case study, what complicated drying the AC closets? a. The AC closet was a tight fit, and you could not place a dehumidifier in them. b. Walls around air handlers always had insulation in them. c. The air handlers were installed, and the builder wanted to dry the closets without removing the air handlers. page 34
Case Study #2, Day 1 Review Quiz 8. Walls with fiberglass insulation inside have the following property: a. They dry slowly, as the fiberglass helps hold moisture. b. They can always dry quickly, since fiberglass is non-porous, and does not hold water. 9. Where were the instructions placed to tell the water mitigation people the locations to place the dehumidifiers? a. In the superintendent's log book. b. On the front door. c. On the kitchen counter. 10. Sweeping and vacuuming water is how many times faster than evaporation? a. 100 b. 1000 c. 250 d. 10,000 page 35
Case Study #2, Day 1 Answers to Review Quiz Check your answers against the correct ones below. If you answered more than 2 incorrectly, please review the case study and take the quiz again. 1. b 2. b 3. c 4. a 5. a, c, d 6. d 7. c 8. a 9. b 10. b Once you have passed the review, you may continue to Day 2. page 36
Case Study #2, Day 2 Introduction Day 2 of the dry-out. The Dehumidifiers (Dehu s) are now ducted under the cabinets or into the ceilings as required. But most of the dehumidifiers have not been working regularly. Power problems Extension cord problems Incompetent worker problems. the usual! page 37
Case Study #2, Day 2 Introduction Each Dehu has an hours log counter on its display. We indicate on each door the hours the Dehu s are in use, and will not pay for the Dehu s that are not running. Where the Dehu has not been running, we may have to cut additional drywall to help dry, or to remove mold. Walls with insulation in them are still wet, and there is concern about proper drying of the walls behind the cabinets. page 38
After completing this module, you will be able to: Describe how to construct ducts to channel dehumidified air into wall cavities behind cabinets, to speed up the dry-out process. Explain the importance of checking the rate of drying with a moisture meter. Explain the importance of cutting open drywall in order to dry out wall cavities containing insulation materials. Explain how and why to spray disinfectant into wall and ceiling cavities to prevent mold and bacteria growth. Objectives: Case Study #2, Day 2 page 39
Ducting dehumidified air under cabinets. Checking the rate of drying Opening additional walls that are drying too slow (usually due to insulation) Disinfecting to reduce mold growth Outline: Case Study #2, Day 2 page 40
Day 2 Use of Ducts Dehu is ducted under kitchen cabinets using lay-flat (poly) ducting. page 41
Day 2 Use of Ducts Dehu ducted into ceiling for 24 hours. Now dry. We then fogged ceiling with disinfectant. page 42
Day 2 Use of Ducts Soffit drying out through access panel. Will fog later, when completely dry. page 43
Day 2 Use of Ducts Upper right: Bath cabinet with closed bottom not easily dried out. Main picture: To aid dry-out, we cut a hole in wall behind bathroom cabinet (yellow arrow). Then the output of the Dehu was ducted into this hole to dry under the bath cabinet with closed bottom. Note: Some of the bath cabinets were open on the bottom, and could be easily dried out with a Dehu or fan in the bathroom. page 44
Day 2 Use of Ducts Hole was cut in wall under another bathroom cabinet. Sprayed with disinfectant inside. Then the output of the Dehu (yellow arrow) was ducted under the bath cabinet using off-theshelf blue colored pool tubing. page 45
Day 2 Use of Ducts Black arrow points to lay-flat ducting connected to pool tubing that directs Dehu output into the wall cavities behind the cabinets. Yellow arrow points to pool tubing inserted into wall cavities under cabinets to facilitate drying out of the wall cavity interior. page 46
Day 2 Use of Ducts PVC pipe connected to end of pool tubing and inserted into wall cavity. page 47
Day 2 Use of Ducts Another kitchen. After cavities were sprayed with disinfectant, dehumidified (dry, warm) air was pumped into ALL wall cavities behind kitchen cabinets. Yellow arrow points to PVC pipe that allows up to 4 connections to the Dehu. page 48
Day 2 Use of Ducts Another kitchen with wet wall behind cabinets getting dried out. In this set up (using a PVC T ) we had the Dehu configured to supply air to only 2 insertions in the walls (yellow arrow). This configuration was optimal for this job. Blue arrow points to drill being used to remove plugs in drywall. page 49
Day 2 Use of Ducts Bathroom cabinet being dried out with only 1 output attached to Dehu. Some of the older model Dehu s did not have much air flow, and could only support one attachment. page 50
Day 2 Use of Ducts If you do not have a Dehu, you can use a wet vac to supply the air. The wet vac, of course, does not supply dry air like the Dehu does, but it does provide air under much higher pressure, and will do a good job drying out wall cavities. You don t need the Dehu to suceed. A wet vac can do the trick. Blue arrow points to PVC wands inserted into walls. We cut these at 45 degree angles. You can connect multiple wands to the wet vac (or Dehu) depending on how you set up the PVC piping (yellow arrow.) page 51
Day 2 Use of Ducts The water mitigation company had some specialized equipment to dry out wall cavities, but they only had enough to dry out walls in 1-2 units. We needed to dry out insulated walls in 20 units. Making what we needed from PVC, pool tubing and lay flat poly duct was very easy, cheap and quick. Additionally, the store-bought wall cavity dry-out products pump regular air into the walls. With our home-made solution we pump dehumidified air into the walls, using the dehumidifiers supplied by the water mitigation contractor. page 52
Day 2 Checking Rate of Drying Inside this insulated wall it was still wet according to moisture meter. page 53
Day 2 Checking Rate of Drying Hallway walls still wet. Wall filled with fiberglass insulation. Baseboard must be removed to permit dry-out. page 54
Day 2 Checking Rate of Drying Another wall with insulation in it that was missed still wet. Many of the walls behind kitchen cabinets also insulated. Day #2: insulated walls still wet. Not feeling confident that all wall cavities will dry out in time to avoid mold. page 55
Day 2 Checking Rate of Drying We had reached in and pulled out some insulation from the wall cavity behind the kitchen cabinets. WET! Blowing dry air on the outside of the wall was not doing it. page 56
Day 2 Checking Rate of Drying Under kitchen cabinets. Outside of wall still wet (yellow arrow). No doubt inside is worse. Dehu s have not been running consistently. Concern about mold starting to grow behind cabinets. page 57
Day 2 Checking Rate of Drying Checking the drying process with moisture meter. Exterior wall in rear of AC closet now dry. (No fiberglass insulation here.) Check interior to see if dry. When dry fog interior with disinfectant. page 58
Day 2 Opening Walls Unit 501: Block wall behind kitchen cabinets. Wall opened up and checked. Wet inside. Need to duct a Dehu into this cavity. page 59
Day 2 Opening Walls The fans have already dried out all the open wall cavities. page 60
Day 2 Opening Walls Missed this closet because it was behind a door. We cut open the wall and put in a Dehu. page 61
Day 2 Opening Walls Inside of unit. Opened wall with insulation inside now completely dry. page 62
Day 2 Opening Walls 95% of the walls inside units are now dry and mold free. At least 2000 linear feet of interior walls had been cut open. page 63
Day 2 Opening Walls In some cases we had to remove extensive amounts of drywall, because we were concerned it could not dry quickly enough. Remember, mold will start to grow in 48-72 hours. page 64
Day 2 Use of Disinfectant After cutting plugs from drywall, we would spray disinfectant such as bleach, or a household disinfectant like Lysol, into wall cavities. Disinfectant helps cut down on mold and bacterial growth. You do not want to spray the outsides of wet walls, as this could cover up internal mold problems. This should never be done. page 65
Day 2 Use of Disinfectant Plugs removed from walls to allow disinfectant to be sprayed inside, and to allow dry air from Dehu s to be pumped directly inside wall cavities. page 66
Day 2 Use of Disinfectant Ceiling drying out nicely, which will be fogged with disinfectant as a precaution. Never fog bleach. Only fog with non-caustic household disinfectants such as Lysol. Disinfectant was used when we were not sure cavities were dry within 48-72 hours, which is the time it takes mold to start to grow. page 67
Conclusion: Case Study #2, Day 2 This concludes Day 2 of Case Study #2. You should now be able to: Describe how to construct ducts to channel dehumidified air into wall cavities behind cabinets, to speed up the dry-out process. Explain the importance of checking the rate of drying with a moisture meter. Explain the importance of cutting open drywall in order to dry out wall cavities containing insulation materials. Explain how and why to spray disinfectant into wall and ceiling cavities to prevent mold and bacteria growth. Please answer the review questions on the following slides page 68
Case Study #2, Day 2 Review Quiz 1. What did we do to try to make sure the dehumidifiers were running continuously? a. Log the hours each day and make sure that at the end of the day the log incremented 24 hours. b. Have someone check on them each hour. 2. At the end of Day 2, which walls were dry? (select all correct answers) a. Walls that had been cut open the day before, had fans blowing on them, and had no insulation in them. b. Walls that had been cut open the day before, had fans blowing on them, and had insulation in them. c. Walls behind kitchen cabinets. page 69
Case Study #2, Day 2 Review Quiz 3. What type of specialized equipment was provided by the mitigation contractor to dry out the wall cavities? a. They had enough store bought equipment to do most of the units, but we had to kludge together something for a few units. b. None. They only provided the Dehu s, and the ducting was home made. 4. When and where was disinfectant sprayed? (select all correct answers) a. The disinfectant was sprayed on sealed up wall cavities so they would not have to be cut open. b. Disinfectant was sprayed into wall cavities behind kitchen cabinets. c. Disinfectant was sprayed through wall openings under bathroom cabinets. page 70
Case Study #2, Day 2 Review Quiz 5. When and where was disinfectant fogged? a. Ceiling cavities and soffits were fogged with disinfectant once they were dried out. b. Fiberglass filled wall cavities were always fogged with disinfectant to keep down mold growth. page 71
Case Study #2, Day 2 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. a 2. a, b 3. b 4. b, c 5. a Once you have passed the review, you may continue to Day 3. page 72
Case Study #2, Day 3 Introduction Day 3 of the dry-out. Air from Dehu s now being ducted into wall cavities behind kitchen cabinets and under bath cabinets. Most units appear to be drying well. Several kitchen cabinets will have to be removed, as there are concerns about how well the walls behind are drying, because Mold can start to grow in 48-72 hours. So we are racing to dry everything before mold has a chance to grow. When we are concerned about drying taking too long, we spray or fog with disinfectant, and/or remove more walls or ceilings, and/or remove cabinets. Mold Under Kitchen Cabinets page 73
Objectives: Case Study #2, Day 3 Objectives are similar to day 2. After completing this section, you will be able to: Explain the importance of knowing what type of insulation is in the walls, and how this affects drying. Describe how to put together and use the equipment to dry wall cavities behind cabinets. Describe the procedures to check to make sure walls with air being pumped into them are drying. Explain the importance of using disinfectant in addition to drying. page 74
Outline: Case Study #2, Day 3 Identifying the type of insulation in the walls that is slowing down drying. Drying wall cavities behind cabinets. Checking drying progress inside walls and behind cabinets. Opening wall cavities and removing cabinets to help dry and inspecting for mold and moisture when drying is slow. page 75
Day 3 Insulation Inside Walls Drywall wet inside of wall (behind baseboard). Why? Because the wall is full of fiberglass soundproofing insulation, and this type of insulation holds water. page 76
Day 3 Insulation Inside Walls Arrow points to concrete wall behind kitchen cabinets. Wall was stuffed with fiberglass insulation. Not easy to dry. Dehumidified air is being pumped into wall from under cabinet. But need to carefully monitor drying efficiency in situations like these. page 77
Day 3 Drying Behind Cabinets Yellow arrow shows plug removed from wall behind bathroom cabinet. Blue arrow shows close up of PVC tubing being run under inaccessible bathroom cabinet bottom to aid in drying. page 78
Day 3 Drying Behind Cabinets In this kitchen, we had 2 Dehu s running. Blue arrow points to wall cavity behind bathroom cabinet being dried out. Yellow arrow points to wall behind kitchen cabinet drying. page 79
Day 3 Drying Behind Cabinets Yellow arrow points to hour log posted on front door. The Dehu is installed in bathroom (bathroom is behind wall in main picture.) Log showed that the Dehu was not running, so we opened the wall, sprayed disinfectant into the wall cavity behind bath vanity, and connected a Dehu to pump dry air through the wall, and then under the bath vanity, to facilitate drying. page 80
Day 3 Checking Drying Progress Laser thermometer operation. Dehu is warm. 108 degrees! page 81
Day 3 Checking Drying Progress Laser thermometer being used to check the drying of the walls. Yellow arrow points to laser dot. If the wall surface is warm, then the dehumidified warm air pumped into the wall cavity is reaching that area. IMPORTANT: If a wall under cabinet is not warm, then the warm air is NOT reaching that area. Another hole needs to be made in the wall in the cool area, and warm air pumped in. page 82
Day 3 Checking Drying Progress Dehu pumping hot air through wall in back of bath vanity. Using laser thermometer, checking hot air coming out from beneath this bathroom vanity. If there is plenty of heat here, we know that the cavity behind was properly drying out. page 83
Day 3 Checking Drying Progress Using the laser thermometer, we checked the temperature of the wall under the cabinets to make sure the entire wall was being heated. When all locations of wall under cabinets were HOT hot air was drying the entire wall cavity. In some cases, we needed to make additional holes, move the tubes and continue drying for another day. page 84
Day 3 Checking Drying Progress Baseboard in hallway just removed. Very wet inside, per moisture meter. Now we must cut drywall behind baseboard and remove all insulation. At this point mold may have already started to form. page 85
Day 3 Checking Drying Progress A little hard to see from this picture, but the lay-flat ducting has become detached from this Dehu. As a result, the wall cavity behind the cabinets is not drying. Spray or fog with disinfectant, and reattach Dehu. IMPORTANT: If the wall cavity has insulation in it you cannot fog. You need to spray disinfectant inside, and then let the air being blown into the cavity aerosolize the disinfectant. The air will then distribute the aerosolized disinfectant. page 86
Day 3 Checking Drying Progress Wall cavity behind the kitchen cabinets in 613 was not being dried out because the ducting had become detached from the Dehu. There was a full time person from the water mitigation company on site to make sure this type of stuff did not happen, but it still kept happening. The hours log does not help. Unit was running, but doing no good. page 87
Day 3 Checking Drying Progress Another unit with the Dehu doing no good. Good thing we were checking, and not leaving this to the water mitigation company! Drying is a race against time. Mold will start to form in 48-72 hours. So these types of human errors can be very costly. Fog wall with disinfectant, reattach Dehu... and carefully monitor. page 88
Day 3 Checking Drying Progress Upper left picture: In a few cases, we could not detect hot air coming out the bottom of the bathroom cabinets. We had to have the vanity toe kicks removed to facilitate drying. page 89
Day 3 Checking Drying Progress Discolored water-damaged cabinet (yellow arrow) that is off of the floor (blue arrow), but somehow got wet, and needs to be replaced. page 90
Day 3 Checking Drying Progress Two inches of water evaporated from toilet overnight with Dehu running. No doubt that wall is dry! page 91
Day 3 Opening Wall & Removing Cabinets Soffit not drying well, so drywall had to be removed. page 92
Day 3 Opening Wall & Removing Cabinets Drywall still wet. Not drying fast. Opened wall and found...rusted steel framing in wall. No way that rusting occurred in 2-3 days! This was a pre-existing condition from a leak in the shower pan. page 93
Day 3 Opening Wall & Removing Cabinets After the dry-out, we want the walls to be sealed back up. In order to plug the wall, we recommend that a drywall plug be glued to a strip of drywall tape (using corner bead adhesive spray). Then the paper tape would be sprayed with same adhesive, and the hole plugged. A little compound to cover the tape would be applied. page 94
Day 3 Opening Wall & Removing Cabinets Yet another problem with the ducting coming loose from a Dehu. We repaired, fogged or sprayed cavity with disinfectant, and continued drying. This cabinet will have to be removed and the wall behind gutted. page 95
Day 3 Opening Wall & Removing Cabinets At the end of Day 3, all was dry except for walls behind 5 cabinets. We added a few more Dehu's to help the slow-drying 5 remaining cabinets, and had the other Dehu's taken out. It had taken more than 72 hours to dry, and we could not be sure that mold had not formed. We therefore decided to remove these 5 cabinets and gut the walls behind, in order to be able to certify them as mold free. When we gutted the walls, we found no mold. Most likely the absence of mold growth was due to the effective use of disinfectant, in addition to drying with dehumidified air. page 96
Conclusion: Case Study #2, Day 3 This concludes day #3 of Case Study #2. You should now be able to: Explain the importance of knowing what type of insulation is in the walls, and how this affects drying. Describe how to put together and use the equipment to dry wall cavities behind cabinets. Describe the procedures to check to make sure walls with air being pumped into them are drying. Explain the importance of using disinfectant in addition to drying. Please answer the review questions on the following slides page 97
Case Study #2, Day 3 Review Quiz 1. What was the laser thermometer used for? a. To check to see if the wall under the kitchen cabinets was being evenly heated by the Dehu. b. To see if warm air was coming out from under bathroom vanities that were having dry air pumped under them. c. All of the above. 2. How were the walls patched after the dry out? a. They were left open. Not sealed because no one would see them once the toe kicks were re-installed. b. Plugs were put back using drywall tape and corner bead adhesive. page 98
Case Study #2, Day 3 Review Quiz 3. What areas were not drying well? (select all that apply) a. Hallway where baseboard was still in place. b. Walls behind all kitchen cabinets were all dried by the end of the 3rd day. c. Walls behind some kitchen cabinets were not drying well because the ducting connected to the Dehu had become disconnected. 4. The hour log on the Dehu's was an excellent way to determine if the Dehu s were on and drying out the wall cavities. a. Yes. The main problem was power cords becoming disconnected, and the hour log made sure the Dehu s were on. b. No. Many times the ducting was disconnected, and the Dehu was not drying even though it was running and the hours clicking away on the hours log. page 99
Case Study #2, Day 3 Review Quiz 5. We made extensive use of an infrared thermographic camera in this case study due to the large extent of water damage needing to be catalogued. a. Yes. The IR camera did an excellent job of finding water inside of wall cavities. b. No. We were on site the next day after the flood, and it was obvious by the water on the floor which walls were wet. page 100
Case Study #2, Day 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. c 2. b 3. a, c 4. b 5. b Once you have passed the review, you may continue to Case Study #3. page 101