Radon gas is dangerous and can build up in your home and pose serious health risks. Here, you will find important information on how radon enters your home, how to test for it, and what actions to take to reduce its levels.
What is radon gas?
Radon is a gas formed by the breakdown of uranium, a natural radioactive material found in all soil and rock. You can't see it, smell it or taste it.
Radon gas can enter your home through cracks and holes in the floors and foundation. Outside, the gas mixes with the air and is not harmful. But radon can reach dangerous levels inside an enclosed space, like your home.
Please visit Health Canada for more detailed information: Radon Reduction Guide For Canadians
Why is radon gas dangerous?
Radon is the #1 cause of lung cancer in non-smokers. The longer you are exposed to high radon levels, the higher your risk.
How to test for radon in your home
Please visit Health Canada for important information on Radon Testing Your Home. Questions? Please contact Health Canada at 1-833-723-6600.
Most homes have some radon gas. Even homes next to each other can have different radon levels. The only way to know how much is in your home is to measure it. Radon levels can change throughout the day, so it’s best to measure for at least 3 months over the winter season. There are two ways to test for radon:
There are two options for testing a house for radon:
- Purchase a do-it-yourself radon test kit
- Hire a certified radon measurement professional to perform the test in your home
What to do if your home has high radon levels
If the radon level is higher than the Canadian guideline of 200 Becquerels per meter cubed (Bq/m³), fix your home. Radon levels in most homes can be reduced by about 80% for the same cost as repairing or replacing things such as your furnace or air conditioner.
Choose a certified radon mitigation professional. Learn how to find a certified contractor in the Radon Reduction Guide.
A building permit is not required in existing homes for most radon reduction projects, as long as the work is non-structural, doesn't affect the plumbing, HVAC, or fire protection systems, and does not interfere with or pose a threat to the health and safety of the occupants.
New home construction - requirements for radon gas mitigation
When building a new house, semi-detached house, townhouse or residential addition, radon mitigation measures must comply with the Ontario Building Code.
The building permit applicant must provide a completed Radon Mitigation Form with the building permit application.
The builder is required to implement one of the following three radon gas mitigation methods:
Option 1: Soil Gas Barrier System
- 6 mil polyethylene under concrete floor
- 6 mil polyethylene between concrete floor and separate floor over the slab
- Perimeter of concrete slab and all penetrations through the slab shall be sealed
Option 2: Subfloor Depressurization, (Full installation)
- Minimum 100mm (4”) pipe installed at or near center of floor area
- Increase amount of granular under the floor at pipe inlet location
- Pipe extended to exterior of the building
- System must include an in-line fan
Option 3: Subfloor Depressurization, (Rough-in only)
- Minimum 100mm (4”) pipe installed at or near center of floor area
- Increase amount of granular under the floor at pipe inlet location
- Pipe to extend above floor with removable seal pipe must be clearly labelled for removal of soil gas
- NOTE: When Subfloor Depressurization is roughed-in only, testing for Radon is mandatory once the home is occupied. Testing must occur over the winter months for a period of not less than 91 days. The test results must be submitted to the City of Niagara Falls – Building Services. If the test results exceed Ministry tolerances a full depressurization system must be installed.
New Home Warranty - Radon Gas
New homes in Ontario come with a warranty that is provided by the builder and backed by Tarion. The warranty covers radon gas levels exceeding 200 Bq/m³ in new homes for seven years from the date of occupancy.
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