Austin Asthma: Cheap Siding Fueling Summer Lungs?

By Franklin Everett Shaw

January 3, 2026

The air in Austin feels different these days, doesn’t it? It’s not just the relentless heat radiating off the asphalt, but something else, something almost…chemical. Could the very homes we retreat to for respite be contributing to the problem?

The culprit might be lurking in plain sight: fiber cement siding.

Fiber cement siding has become ubiquitous in Austin’s new construction and renovations. It’s touted as a durable, low-maintenance alternative to wood, perfectly suited for our unpredictable Texas weather. But beneath the surface of its appealing price point and purported resilience lies a potential health hazard that Austin homeowners need to understand, especially those battling asthma.

Let’s dive into the potential link between fiber cement siding and Austin’s worsening summer asthma seasons.

Fiber cement siding, typically composed of cement, sand, and cellulose fibers, often contains other additives. These additives can include chemicals like formaldehyde, silica, and various volatile organic compounds (VOCs). While manufacturers claim these materials are inert once the siding is installed, the reality can be more complex, especially in Austin’s extreme heat.

The potential for off-gassing is a significant concern. Off-gassing refers to the release of chemicals from a material into the air over time. Austin’s scorching summers can accelerate this process, causing fiber cement siding to release VOCs into the surrounding environment. These VOCs can then seep into homes, contributing to indoor air pollution.

Consider James Hardie siding, a popular brand in Austin. While they provide safety data sheets, these often focus on installation hazards (dust inhalation) rather than long-term off-gassing. Independent testing of similar building materials has revealed the presence of formaldehyde and other VOCs, even after installation.

So, how can Austin homeowners determine if their fiber cement siding is impacting their indoor air quality?

First, identify the brand and type of fiber cement siding used on your home. This information is often available in your home’s construction documents or from the previous homeowner. Contact the manufacturer to request detailed information about the chemical composition of your specific siding product.

Next, consider DIY air quality testing. While not as comprehensive as professional testing, DIY kits can provide a preliminary assessment of VOC levels in your home. Look for kits that specifically test for formaldehyde and other common VOCs found in building materials. Home Depot and Lowe’s carry a variety of these kits, ranging in price from $50 to $200.

For a more thorough evaluation, consider professional air quality testing. A qualified environmental consultant can conduct a comprehensive assessment of your home’s indoor air quality, identifying specific pollutants and their sources. In Austin, companies like Air Quality Assessors and RTK Environmental offer these services. Expect to pay between $300 and $800 for a professional air quality test.

Here’s a step-by-step guide to conducting a basic DIY air quality test:

Choose a test kit: Select a kit that tests for a broad range of VOCs, including formaldehyde.
Follow the instructions carefully: Each kit has specific instructions for sample collection and analysis.
Place the collection devices strategically: Place them in areas where you suspect off-gassing is occurring, such as near exterior walls with fiber cement siding.
Send the samples to the lab: Most kits require you to send the collected samples to a laboratory for analysis.
Interpret the results: Compare the results to established air quality standards. The EPA provides guidelines for acceptable levels of various pollutants.

But what if the tests confirm your suspicions? What can you do to mitigate the risks?

Ventilation is key. Increase ventilation by opening windows and using exhaust fans, especially during the hottest parts of the day. Consider installing a whole-house ventilation system to continuously circulate fresh air.
Air purifiers can help. Invest in a high-quality air purifier with a HEPA filter and activated carbon filter. These filters can remove particulate matter and VOCs from the air. Look for air purifiers specifically designed for removing formaldehyde.
Seal the siding. Applying a sealant to the exterior of the fiber cement siding can help to reduce off-gassing. Choose a low-VOC sealant specifically designed for fiber cement. Consult with a professional contractor for proper application.
Consider remediation. In severe cases, remediation may be necessary. This could involve removing and replacing the siding with a less-toxic alternative. This is an expensive option, but it may be necessary to protect your health.

One common mistake homeowners make is relying solely on air purifiers without addressing the source of the pollution. Air purifiers can help to clean the air, but they won’t eliminate the problem if the siding is continuously off-gassing.

Another pitfall is neglecting proper ventilation. Simply opening windows occasionally is not enough. A consistent and effective ventilation strategy is crucial for removing pollutants from your home.

Let’s consider a hypothetical case study: The Smiths, a family living in a newly built home in the Mueller neighborhood of Austin, began experiencing increased asthma symptoms after moving in. They suspected the fiber cement siding, a cost-effective choice by the builder, was the culprit. After conducting a professional air quality test, they discovered elevated levels of formaldehyde in their home. They implemented a combination of increased ventilation, air purifiers, and sealant application, which significantly improved their indoor air quality and reduced their asthma symptoms.

The challenge for Austin homeowners is that information about the potential health risks of fiber cement siding is not readily available. Manufacturers often downplay these risks, and builders are primarily focused on cost and durability. It’s up to homeowners to educate themselves and take proactive steps to protect their health.

Don’t rely solely on manufacturer claims. Do your own research and consult with independent experts.

The Texas Department of State Health Services (DSHS) offers resources on indoor air quality and potential health hazards in the home. Contact them for information and guidance.

Ultimately, the decision of whether or not to use fiber cement siding is a personal one. However, Austin homeowners need to be aware of the potential risks and take steps to mitigate them. By understanding the chemical composition of fiber cement siding, the potential for off-gassing, and the available testing and mitigation methods, you can make informed decisions to protect your health and the health of your family.

Don’t let your dream home become a source of respiratory distress. Take control of your indoor air quality and breathe easier in Austin.