Friday, March 31, 2017

Does your home have dangerous levels of radon? Here’s what you need to know

Radon gas in your home could be affecting your health, and you may not even know it.

The effects of radon gas have been studied extensively in recent years and are now definitively linked to lung cancer. Health Canada first implemented a radon guideline in 1988. Based on long-term exposure risks, in 2007 they reduced the safe limit of radon exposure from 800 Becquerel per metres3 (a Becquerel is a unit of radioactivity) to 200 Bq/m3. As a result of the change to the Health Canada guidelines, the Alberta Building Code was updated in 2014 to include requirements for rough-ins that will facilitate the future installation of radon mitigation systems, should they be required. Prior to 2014, there was no requirement in the Alberta Building Code to install these rough-ins.

The Alberta Building Code does not currently require houses to be tested for radon, and does not require radon mitigation systems to be installed (other than the rough-in for them). The City has staff that advise on numerous provincial and national building code committees. Through this work, we ensure that the latest radon safety issues are given appropriate consideration by code-writing authorities.

Since the only way to know what levels exist in your home is to test, you should purchase a do-it-yourself radon test kit or hire a radon measurement professional, and become informed. These tests come in several types and can be purchased online or from your local hardware store. They are relatively inexpensive and should be conducted over a period of three months for most accurate results. If the levels in your home exceed 200 Bq/m3, Health Canada recommends you reduce your radon levels.

So what is radon?
Radon occurs naturally in the environment and is invisible, odourless and tasteless. It is a radioactive gas produced by the decay of uranium in soil and rock. When it escapes the ground into the atmosphere, it is diluted by the air around us, going unnoticed. However, when it is escapes into an enclosed space like a basement, it can become concentrated and begin to cause problems.

Based on this potential health risk, the Alberta Building Code (ABC) requires that a radon remediation system rough-in be installed for all new construction projects. If you are adding to the footprint of your home, this will affect your renovation project.

Rough-in requirements for new construction in the Alberta Building Code
The reason the ABC requires a rough-in installation on new construction is to help with future remediation of radon gas if tested levels are above the recommended concentrations. It is important to know that the remediation of radon gas is a homeowner responsibility, and not required by the building code. Unfortunately, due to the nature of airborne gases, it is impossible to know if a future remediation system will be required. Mandating a rough-in at the new construction stage ensures that the greatest number of Albertans will have the ability to install a remediation system in the future if they require it. This is because installing a remediation system without a rough in can be costly and difficult to do in an existing home. When compared to the cost of providing a rough-in prior to pouring concrete, it makes sense to implement this proactive approach. The additional costs at this stage are minimal and require only a few modifications to normal building practice.

If you are planning an addition to your home you will need to provide a detail of the rough-in and label the rough-in inlet and outlet locations on your application drawings. The rough-in detail must include a sealed air barrier, an open end pipe to collect soil gas, granular material beneath the slab, and a capped/labelled stub up for future use. If after the space is built and occupied testing shows that the levels of radon are above the Health Canada threshold, an extraction system will be easy to install.

Vanessa Gash, LEED AP
Safety codes officer, building
Commercial plans examiner, Calgary Building Services, 
Planning & Development
Additional information on radon and its mitigation are available online at Health Canada www.hc-sc.gc.ca. If you have specific questions regarding installation requirements for your radon rough-in please visit calgary.ca/radon or contact The City of Calgary’s Planning Services Centre at 403-268-5311.

This blog was written by Vanessa Gash. Vanessa has been a plans examiner with Calgary Building Services at The City of Calgary for several years, and is a graduate in Architectural Engineering Technology from College of the North Atlantic. Prior to working for The City, she spent many years working in the commercial and residential construction industry in Calgary.

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