Troubleshooting Bumps in the Night and Other Building Issues

Earlier this year, a homeowner in Michigan complained to his builder about strange noises. Over several months, the builder’s team explored every room, inspected the exterior, crawled over the roof, and rooted around in the basement, but they couldn’t figure out what was causing the noise. Later, after they’d spent considerable time and expense, they discovered that these mysterious noises weren’t the result of a construction defect; rather, they were only in the homeowner’s head. (Really!)

While dealing with homeowners who hear phantom noises doesn’t happen often, complaints about noises and odors are common, and it’s often hard and time-intensive to pinpoint the cause. And if you can’t find out what’s causing the problem quickly, you may be risking your customer’s safety, as well as their satisfaction.

Using a deliberate and thorough troubleshooting process will save you time and money. This process should guide you through which questions to ask, making it easier and quicker to nail down the cause. Determining the cause of the problem yourself will save you the cost of hiring expert help. But even if you can’t determine the cause, doing preliminary fact-finding will save the experts time and help them get to the solution quicker, again saving you money. Following a deliberate troubleshooting process will also help to ensure customer safety and satisfaction. In addition, it will help guide you to the root causes of issues, and help you to modify your practices so that the problem doesn’t show up again down the road.

Let’s take the example of an odor problem that IBACOS helped a production builder solve in the northern Midwest. We’ll call it The Case of the Smelly Home. The customer was complaining of a nasty odor in her home—a noxious concoction of wet animal, old sweat socks, urine, and dead fish. The builder investigated for months before calling us for help.

In The Case of the Smelly Home, the odor was strongest in the master bathroom but noticeable through the rest of the house. The odor coincided with strong rainstorms, and was strongest when the storms came from the southwest, which is where the master bath is oriented. The odor was worst during periods of high humidity. The woman who lived in the home was extremely sensitive to strong odors. She was losing sleep and was plagued with various allergic reactions, including headache, runny nose, and cough. In addition to this immediate health risk, there was the builder’s reputation to consider, as a foul-smelling house is sure cause for customers to gripe to their friends and family about the quality of the builder’s homes.

An interview with this homeowner gave us valuable clues. There was nothing out of the ordinary regarding the occupancy or use of the house; however, the temperature was typically around 80°F in the wintertime, and a humidifier was in constant use. The odor started in the first spring of occupancy.

During inspections, the builder did smell the odor, though not to the extent that plagued the homeowner. Initial solutions focused on the path of the odor, not the source. Fans, lights, and HVAC vents were moved and sealed. The owner was instructed to run, not run, or run the fan for shorter periods—all to no avail.

We reviewed the materials and practices the builder used, what standards the house was built to, and how airtight the house was. The builder hadn’t made any changes to the design or in the purchasing specs, and the problem was only occurring in this one home. The house was only moderately tight in terms of airtightness, which means that some inside air was finding its way into insulated assemblies, like the walls and attic.

Based on the available data, we suspected that a moisture source was causing either the growth of mold or bacteria somewhere in the house close to the master bedroom, or that a building material was somehow causing the offending odor.

When we visited the home, we looked for and found unsealed penetrations from the master bathroom to the attic. We looked for obvious problems in the attic—evidence of moisture condensing on the roof, mold growth, standing water, leaks, or a lack of roof vents—but found none, though we did detect a slight odor.
What we did find was that the edge of the blown-in fiber glass attic insulation was damp to the touch around the perimeter of the house, but not near the soffit vents.

We also found that the master bathroom fan unit wasn’t sealed well, making it easy for the smell in the attic to infiltrate the area. We conducted a pressure test and found that the master bathroom was positively pressurized with respect to the bedroom, which means that the smell was being pulled out of the bath, into the bedroom, and beyond.

With no sign of mold, bacteria, or other organisms that might be the cause of the odor, we narrowed our search down to the damp insulation. Was there something in the product that could cause this problem? When we contacted the insulation manufacturer to ask whether they’d received complaints about odor problems before, we struck gold. They had, and told us that the smell was caused by trimethylene, a bonding agent in their insulation that releases an odor when it gets wet. It seems that this homeowner was very sensitive to the smell caused by the wetting of the trimethylene. So, while it is likely that more of this builder’s homes had damp attic insulation based on the typical construction practices and climate zone in which the houses are built, most people wouldn’t even notice the odor. We also discovered that the insulation manufacturer was receiving complaints around the same time that a non-standard condition was introduced in the manufacturing process.

While most customers don’t have a severe reaction to the smell of a bonding agent, we recommended the builder change their practice to limit the introduction of attic air into the house by improved airsealing, without changing the type of insulation in the attic. This would limit the future possibility of odors in the attic getting into the house. But because this customer was extremely sensitive, we recommended removing the insulation from the attic to eliminate the source, then airsealing all fans and penetrations between the attic and the house. As part of this airsealing, we recommended making sure all the wall-to-ceiling intersections and the chase penetrations were well sealed, after which unbonded insulation was installed to eliminate binder reaction to moisture. IBACOS feels that bonded insulation is an acceptable material, and that this kind of problem is not common. This particular case required an aggressive action, due to the homeowner’s reaction.

While moisture can enter the attic from many sources, and the house was humid, we believe the source was high indoor ambient humidity. We ran temperature and humidity tests that showed no need for adding humidity, so the builder recommended to the homeowner that she not operate the humidifier. This was especially important after airsealing the attic, as tighter houses generally have higher indoor humidity levels. If additional moisture is added by a humidifier, the homeowner might run the risk of creating an environment that could create other odor problems.

Because the customer was satisfied with this solution, no follow-up testing was necessary.

Customer complaints like hearing noises or smelling bad odors are fairly common, but trying to solve the problem without following a consistent and effective process will cost you in the end—both in labor time and expenses, employee frustration, and risking customer satisfaction. Defining the problem and doing some basic detective work will guide you along the trail of solving the problem, ultimately reducing your costs, and keeping your homeowners happy.

Read the related article on a best practice troubleshooting process.