Every homeowner should be concerned about the effects of radon gas in their home. Radon is a toxic, odorless gas that can cause chronic respiratory illness if you or your family members are exposed to it over a long time. Taking precautionary measures to reduce the radon gas levels in your home not only increases your indoor air quality but also keeps you and your family safe. Radon mitigation systems are any devices or processes that help reduce radon concentrations in commercial or residential buildings. This article discusses five types of radon mitigation systems and their effectiveness in reducing radon gas levels in buildings.
- Drain-Tile Suction
Drain tiles collect water and channel it through a pipe to a drainage area or into a sump. Attaching an exhaust fan to the collection pipe or sealed sump can help in the extraction of radon from the soil beneath. A water-filled trap is installed in the pipe beyond the point where you have attached the fan to prevent the drawing of outside air from the end of the collection pipe. Drain-tiles that form a continuous or partial loop around the house can be used to extract radon from the surrounding soil and vent it outside your home.
- Block-Wall Ventilation
The concrete blocks in basement walls contain hollow spaces that are connected both vertically and horizontally. Radon from the ground can enter the wall through joints or tiny cracks and travel through these connected spaces between concrete blocks before it gets inside your basement and into your home. The block-wall ventilation system uses two basic approaches to get rid of radon levels in a building. It can either blow air into block walls to prevent radon from entering the building (wall pressurization) or draw the radon from the spaces within the concrete blocks before it can get inside the building (wall suction).
- Sub-Slab Suction
The basement floors of most houses are built of a concrete slab poured on top of crushed rock or the soil beneath. The sub-slab suction technique draws radon underneath the slab and vents it away from the house. Individual pipes are inserted into the designated space under the concrete slab and attached to a fan that ventilates the soil gas away from a home’s foundation. These pipes can be inserted either horizontally at a level beneath the slab through a foundation wall or vertically downward from inside the house. These pipes exhaust radon at roof level and away from the windows to prevent it from re-entering the house.
- Forced Ventilation
The forced ventilation method uses fans to maintain the desired rate of air exchange independent of weather conditions. It is used to replace radon-laden indoor air with outside air and neutralizes pressure if you are using a fan that is big enough. Forced air fans provide better radon mitigation compared to natural ventilation, which is often achieved by opening windows. For instance, a fan can blow fresh air into the house continuously through the central forced-air ducting and supply registers with all doors and windows closed. It is advisable to close off or not use the basement when ventilating the lowest level of your home until it is professionally recommended to be safe for entry.
- Covering Exposed Earth
Exposed earth in the basement, storage areas, sumps, drain areas, and crawl spaces are often the major entry points for radon gas in a building. It is crucial to excavate any basement earthen floor as required before installing poured concrete. At least four inches of crushed stone should be poured over the earthen floor before covering it with concrete to allow easy radon mitigation by sub-slab suction should it be required at a later date. It is also important to seal all joints properly to enclose the air spaces. During this procedure, a small fan should be installed preferably at roof level to exhaust the air to the outside. A crawl space that is connected to a basement can be ventilated, covered, or sealed off from the basement.
The radon mitigation system that works best for your situation may vary depending on the type of your home’s foundation. A radon mitigation professional may conduct some diagnostic testing to determine the type of mitigation system to install in your home. It is important to ensure all cracks and openings in the foundation are properly sealed. Not only does this help limit the flow of radon into a home, but also increases the efficiency of your radon mitigation system.