Purple Mountain Radon serving Cascade, CO

Apartment Radon Mitigation Designed to Blend In | Colorado Springs, CO Challenge

An apartment unit in Colorado Springs had a pre-mitigation radon concentration of 19.8 pCi/L—nearly five times the EPA action level of 4.0 pCi/L.

Designing the sub-slab depressurization system presented several challenges. Working space inside the apartment was limited, and the radon pipe needed to exit through the brick exterior wall at the location of the fan-cover baseplate. Outside, the clearance beneath the roof overhang was extremely tight. The building’s steep, metal-clad false-mansard façade also made routing a conventional PVC exhaust riser difficult and visually intrusive.

Solution

Purple Mountain Radon installed a sub-slab depressurization system with the pipe exiting directly through the brick wall into the exterior fan enclosure. A compact 90-degree elbow was installed immediately above the fan to clear the projecting overhang. Because the building already had several rectangular downspouts serving the roof-drainage system, we suggested using a 4-by-3-inch downspout-style exhaust riser across the sloped façade. This allowed the radon system to follow the building’s unusual geometry while closely matching the appearance of the existing downspouts.

Result

The completed radon mitigation system provides the necessary exhaust routing while blending naturally with the apartment building’s exterior. Instead of appearing like a large PVC pipe added to the façade, the riser looks consistent with the building’s existing drainage components.

Post-mitigation testing will provide the final radon result for this apartment.

A homeowner in Colorado Springs, CO, who rents out their property, needed to reduce radon levels to provide a safer environment for their tenants. With radon levels measuring 7 pCi/L—above the recommended limit—they recognized the importance of addressing the issue promptly. They chose Purple Mountain Radon due to their expertise in handling complex radon mitigation, especially in homes with multiple radon entry points.

The problem stemmed from radon seeping into the home through both the basement and an unsealed crawlspace, allowing harmful gas to accumulate indoors.

How We Fixed the Problem:

• Installed a gas mat on the crawlspace floor to enhance airflow beneath the vapor barrier.
• Encapsulated the crawlspace by covering the ground and the lower portion of the foundation walls with a durable plastic vapor barrier, creating an airtight seal.
• Added a primary suction point in the basement slab to extract radon gas effectively.
• Connected the radon exhaust pipe through the crawlspace, linking it to the gas mat and venting the gas outside.
• Installed a radon fan to maintain consistent suction and a manometer to monitor system performance.

What’s unique about this situation:
The combination of a basement and an unsealed crawlspace required a dual approach using both sub-slab and sub-membrane depressurization. This comprehensive system effectively addressed radon infiltration from multiple sources, giving the homeowner confidence that their tenants are better protected.

If you're concerned about radon levels in your rental property, Purple Mountain Radon has the expertise to create a customized solution—contact us today!

1. Why they needed a radon mitigation system:
   The homeowner was concerned about high radon levels in their Colorado Springs home, especially with a newborn in the house. Radon exposure is a serious health risk, prompting the need for a mitigation solution.

2. Why the customer chose the company:
   Purple Mountain Radon was selected due to their expertise in radon mitigation and their ability to provide a customized solution to meet the homeowner's specific needs, including both safety and functionality.

3. What's causing the problem:
   The radon problem was traced back to an un-encapsulated crawlspace with exposed soil, allowing radon gas to enter the home.

4. How We Fixed the Problem (Mitigation Process):

   • Encapsulated the crawlspace with a 6-mil vapor barrier to prevent radon from entering.
   • Attached the vapor barrier to the radon mitigation system for efficient gas extraction.
   • Installed a 20mil vapor barrier and a drainage mat in part of the crawlspace to provide extra protection and improve airflow, as requested by the homeowner for storage use.
   • Connected the radon system to the exterior venting system for long-term radon mitigation.

5. What's unique about this situation:
   The homeowner’s request for part of the crawlspace to be used for storage required a customized solution. To accommodate this, Purple Mountain Radon used a stronger 20mil vapor barrier and added a drainage mat to maintain proper airflow beneath the barrier while still meeting radon mitigation standards.