IAQ IQ, Fall 2024
©2024 Jeffrey C. May
I’m a retired ASHI member, but I still enjoy attending ASHI conferences and meetings, where I catch up with old friends and hear some of their stories about interesting problems they encountered on their home inspections. In this newsletter, I am sharing a few stories from my indoor air quality investigations.
MUSTY ODORS
A musty odor developed in a 19th Century Victorian after cellulose insulation had been blown into the walls from the exterior. In one room where the odor was strong, the plaster and insulation had been removed, and the cellulose insulation was damp. An exterior inspection at that spot revealed that the clapboards had not been properly caulked and sealed into place.
I found some recent mold growth on the sheathing and in the damp insulation. I also found ancient mold growth in the wall cavities (the spores were desiccated). When the cellulose insulation was blown into the cavities, air flowed out of the cavities through electric outlets, light switches, weight boxes for the sash windows, and other openings and gaps in the walls. This air carried ancient dust and the spores it contained. The sheathing and framing in the exposed wall cavities had to be cleaned and sealed; the clapboards had to be properly installed; and the surfaces in the house had to be thoroughly cleaned to remove allergenic dust.
Mold spores remain potentially allergenic even when non-viable.
In another property, a raised ranch, I discovered an unexpected source of a musty odor on the lower level. The house had been in the family for three generations; now a young couple, their daughter, and the grandmother lived there. A lot of work had been done to the house, and the family was very happy living there, but the odor was so irritating to the young woman that she was considering asking the entire family to move. She described the odor as “dank” and “soil-like.”
Several odor sources were present. First, a pipe that passed through a wall had an opening around it. The sewer cleanout was on the other side of this wall, and there was a small leak in the sewer-pipe cap. Second, though the space under the stairs had supposedly been thoroughly cleaned and the surfaces had been sealed, some old, moldy pieces of insulation and some exposed dirt were still there. In addition, the back of the stairs had not been vacuumed or spray-painted to adhere residual dust.
The family needed to have the sewer pipe cap repaired, the space under the stairs re-cleaned, the exposed dirt in that space covered with a mesh-reinforced vapor barrier or with some cementitious material, and the back of the stairs cleaned and sealed.
In another property – a real estate office – I was asked to investigate a building odor. I knew as soon as I entered the offices that the odor was caused by a shrew or two. These animals look like mice but have longer snouts. Shrews exude a musk that is horrendously smelly, and they defecate and urinate in large piles that get moldy. I found the entry point for these animals at the exterior, and by setting up negative air pressure with fans, I also found the wall cavity where their nest was located. The building owner faced a major clean-up job, and any gaps or openings at the exterior had to be sealed.
I found other problems, too (surprise!).
- Evidence of mice on top of the ceiling tiles in a drop ceiling (hence the shrews, which eat mice).
- Mold on some of the drywall.
- Leaks in the boiler room.
- More evidence of leaks in an exterior closet. The wall had to be opened up so that the leak source could be identified and repairs made. Surfaces in the wall cavity then had to be cleaned and sealed, for there was probably mold growth present.
MOLD GROWTH
A couple was worried about mold in their basement and had banned their son from using the family room down there. They were right to be worried. I found mold growth in the couch where he used to sit for hours, playing video games. I also found allergenic dust on top of pipes and on framing in an unfinished part of the basement.
I recommended that the family have the basement thoroughly cleaned and surfaces sealed under containment conditions. Then they had to control the relative humidity (RH) down there more efficiently through dehumidification in three seasons, as well as through consistent heating in the finished room from late fall to early spring.
The RH in an unfinished basement or a crawlspace should be no higher than 50% and in finished basement space, 60%. If the RH rises above these levels, the RH in air in contact with cool surfaces can be above 80%. Then some kinds of mold including allergenic Aspergillus and Penicillium species can grow.
I again found other issues of concern.
- A crawlspace under an addition was full of mold growth.
- Many of their wool area rugs were shedding wool fibers, which can be irritating to inhale.
- They also had feather-filled furniture. Feather fragments can also be irritating to inhale, and some feather-filled goods emit bird-bloom particles, the inhalation of which can cause a respiratory illness called hypersensitivity pneumonitis or HP.
- The family didn’t have dust-mite encasings on their box springs, mattresses, and bed pillows.
Exposure to dust-mite allergens is a major cause of asthma and allergy symptoms.
- They were using a laundry detergent that contained enzymes, which can cause respiratory symptoms and skin irritation in people who are sensitized to mold (the enzymes in such products are chemically similar to the enzymes some molds and bacteria produce).
Some of the “fixes” were expensive – like the crawlspace remediation, and the rug and furniture replacements. Some were not as costly: installing dust-mite encasings on mattresses, box springs and pillows; and using a different laundry detergent.
UNSUPPORTIVE PARTNERS
Almost all of our clients have environmental sensitivities and are sneezing, wheezing, and coughing in some indoor spaces. It’s not unusual for one person who lives in an indoor space to be suffering health symptoms while another person living there feels fine. Usually the “healthy” person is very sympathetic toward the other person’s suffering, but this isn’t always the case.
Connie and I used to take the month of February off and drive to Florida, where we rented a condo for four weeks of sun and warmth. During one of those trips, while we were on the road we picked up a message on our work number from a woman who lived about 20 miles away from our route. She said that the washer and dryer were located in the mechanical room, near the boiler. Often when she went down there to do laundry, she said she suffered from headaches. She added that her husband was convinced that her complaints were an excuse to get him to take full responsibility of laundry tasks.
As soon as I drove up to the house, I suspected what the problem might be. The formal front door and hallway behind it extended beyond the footprint of the main part of the house. On the left was an extension wing, so an “alley” was created between the front door and the wing. I could see two pipes sticking out from the siding in this “U-shaped” formation.
When I entered the house, I saw the husband standing at the top of the stairs leading to the second floor. I greeted him, but he just glared at me and disappeared into a room on that level. In the basement mechanical room, I saw that one pipe was for the exhaust for the direct-vented boiler, and the other pipe was the fresh air intake for the mechanical room. Due to the proximity of the intake and the boiler vent, combustion gases were sucked into the mechanical room when the boiler was operating. The laundry facilities were in the boiler room; levels of combustion gases were not high enough to cause the CO detector to go off, but this woman was obviously more sensitive to combustion gases than her husband was. She felt vindicated after my site visit.
What does all this have to do with home inspections? We home inspectors and indoor air quality investigators alike have to keep our eyes open for problems other than clients’ specific concerns. If you find something that worries you, trust your instincts, and recommend further evaluation as needed.
THE INTERRUPTED HOME INSPECTION
I’m going to end this newsletter with a story from my home-inspection days.
When I arrived at the property, the seller was standing out front, waiting for me. His pickup was parked in the driveway. The prospective buyer drove up a few minutes later and parked her pickup next to his. It was a direct sale, so no real estate agents were present. It’s always potentially awkward when a seller is present during a home inspection, but in this case, the seller wasn’t about to step aside. As usual I started at the outside of the house with both the seller and prospective buyer walking beside me. I noticed some splash marks along some areas of the exposed foundation wall. I commented that poor control of roof water at the exterior can cause splash as well as water intrusion below grade.
When I got to the word “grade,” the seller scowled at me and snarled, “I don’t have water problems in MY basement!”
“Hey, give the man a chance to speak,” the buyer said.
“Don’t tell me what to do, toots!” he snapped.
“Don’t call me toots!” she said, raising her voice. And with that, she turned on her heel, hopped back into her pickup, and drove away in a cloud of dust.
“To hell with it!” said the seller. He turned around, got into his pickup, and drove away in another cloud of dust.
I was left standing alone next to the house, looking at the dust clouds. My home inspection had lasted about 11 minutes: the shortest home inspection I had ever conducted. At that point, I just shrugged and headed off to Duncan’ Donuts. Needless to say, I was never paid.
It’s fun to swap stories, isn’t it?
The photographs, micrograph, and scanning electron micrograph are the property of May Indoor Air Investigations and can only be used with permission. jeff@mayindoorair.com
GREAT NEWS FOR HOME INSPECTORS AND THE HOME INSPECTION PROFESSION!
ASHI’s October magazine “The ASHI Reporter (pages 24 and 25) contains an article titled “Waving Goodbye to Waiving Inspections,” by home inspector Mike Atwell, who was instrumental in getting Section 101 of Chapter 145 of the General Laws of Massachusetts amended. The article states that: “The executive office of housing and livable communities shall promulgate regulations to ensure that no seller of any residential structure or a residential condominium unit or any agent thereof shall: (i) condition the acceptance of any offer to purchase on a prospective purchaser’s agreement to waive, limit, restrict or otherwise forego any prospective purchaser’s right to have the structure or unit inspected, except when the sale of the structure or unit is to occur at an auction conducted by an auctioneer licensed under chapter 100…”
As Mike writes, “The law will be enforceable when the regulations are done….The Governor’s Housing Office is now charged with developing regulations over the next few months to implement the intent of the law. We will be working with them on that.”
Mike was honored to accept ASHI President Mark Goodman’s request to chair the Legislative Committee at ASHI National. Mike’s first priority in this position will be to “develop a call-to action package outlining what we did, what we learned, and samples of all our correspondences to be available to other chapters in the hopes of saving them valuable time and money.”
Mike welcomes people to get in touch with him if they have questions or would like to offer help in this important effort: https://jmhi.com.