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The Stack Effect and Your Home

The stack effect is a phenomenon that impacts your home in many ways including unpleasant odors, mold growth, and vast temperature differences. Peak Structural can help address this issue.

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If you have a vented crawl space under your main living area, you may notice problems throughout your home including unpleasant odors, mold growth, and vast temperature differences. This is because of the stack effect. Read on to learn more about this phenomenon and how it affects your home.

How Does the Stack Effect Work?

The stack effect, also known as the chimney effect, involves the natural airflow in your home from bottom to top. If your home was built on top of a vented dirt crawl space – which is quite common throughout Denver, Colorado Springs, and the Pikes Peak region – the stack effect is likely impacting your home’s health and safety.

Open vents allow unconditioned outside air into the typically cooler crawl space. When an abundance of warm air infiltrates through open vents or cracks, this lighter air will rise to the upper floors. In the summer, hot air can rise from your crawl space to fill your home, and in the winter, the much denser cold air can actually push this warm air up and out of your home. Building code has traditionally called for crawl spaces to be constructed with vents. The intention was to allow better airflow to reduce humidity (even though Colorado is more arid) and the likelihood of mold growth. However, foundation experts have found this practice to cause the problems it was intended to prevent.

The Risks of the Stack Effect

Because of the stack effect, anything in your crawl space such as mold spores and growth, pest waste, and nasty odors is also circulating in the air throughout the rest of your home and affecting you.

Mold Growth

Mold grows and thrives in dark, humid areas like your crawl space. Even though Colorado is a drier state, humidity can still form in your partially below-grade crawl space. Once mold begins to take hold in the crawl space, open vents, the stack effect, and your HVAC system can help its spores travel upwards into the rest of your home and circulate throughout the air. These spores can then latch on to your walls or other organic surfaces. Mold can be toxic and dangerous to humans and pets by aggravating existing health problems or leading to new issues like asthma and allergies in otherwise healthy individuals.

Unpleasant Odors and Poor Air Quality

If you notice nasty smells around your house that you can’t seem to pinpoint or still exist even after a thorough cleaning, these nuisances could originate from your crawl space. Mold has a distinct, pungent odor, as do wet insulation and pest droppings and carcasses. Not only are these odors unpleasant, but they also contribute to poor air quality in your home.

High Energy Bills

The infiltration of hot air in the summer and cold air in the winter can make your upper floors feel hot and cold, respectively. This leads to more reliance on your HVAC system to create a more comfortable living environment. But as it works to overcome the temperature difference, it can continuously run and lead to higher electric bills. The systems also can be overtaxed, break down more, and require frequent maintenance or replacement.


Just as open vents allow outside air, water, and pests into your crawl space, the stack effect allows these nuisances to further affect your home. Water in your crawl space can contribute to humidity and mold growth, and the air can be filled with unpleasant odors and mold spores.

It is crucial to address the stack effect in your home. Not only can mold, nasty smells, and pest issues wreak havoc on your home, but the stack effect also contributes to other damage and money wasted on high electric bills. Among other benefits, fixing the stack effect will help you create a more energy-efficient home and a healthier living environment.

The best way to fix the stack effect in your home is to consult with crawl space experts like the team at Peak Structural. After a thorough inspection, they can recommend and install solutions including airtight vent covers and a thick and durable vapor barrier to fully seal your crawl space and keep the stack effect at bay.

Call Peak Structural for a Free Inspection

The stack effect can lead to a variety of problems in your home that impact your health and safety. Effectively combatting this phenomenon involves help from local crawl space professionals. The expert team at Peak Structural is well-versed in crawl space issues and how to permanently address them. Our durable vapor barrier, vent covers, and other crawl space solutions help seal and condition your crawl space to eliminate the negative impacts of the stack effect. We are proud to offer free inspections to homeowners throughout Denver, Colorado Springs, and the Pikes Peak region, and we look forward to helping you create a safer and healthier home.

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