Modern building practices have created homes and buildings with significantly better energy efficiency over the last few decades. The improvements to insulation and weather tight construction has reduced the air exchange rates in your home and workplace. As a result this has increased the health effects from building materials, mould and other contaminants. The build up of high radon levels has also become a prime concern. The air you breathe is essential to good health for you and your family.
Having the opportunity of being involved in radon mitigation for over 37 years Algoma Radon Testing can assure you that the most efficient, effective and reliable radon gas mitigation system is a system that removes the radon before it can migrate into your home or building. It is much more difficult to remove radon once it has been confined.
The following is a brief explanation of the most reliable radon mitigation systems:
Sub-slab Radon Depressurization System
This is a radon reduction system where the under floor of the concrete pad is placed under a negative pressure by operation of a radon fan. The radon laden air is removed and exhausted to the outside via a plenum created by gravel and in some cases a series of pipes placed underneath the concrete floor.
Sump Hole Suction Radon Removal System
Similar to the sub-slab depressurization method this radon reduction system exhausts radon laden air from the foundation weeping tile system via the sump pit. The air is exhausted to the exterior of the building.
The sealing method involves sealing of all openings and penetrations through a concrete slab and walls. This would include all floor cracks, perimeter cracks, cracks around floor drains and jack posts and any other penetration that would allow a gas to flow. The sealing method may act only as a temporary fix or assist in the Sub-slab Depressurization System. Before considering sealing as the only radon reduction method, you should look at all your alternatives. You can, however, seal off large openings around sumps and utility pipes protruding through the concrete. It is possible that these fixes may sufficiently lower radon levels.
Housing Units With Earthen Floors (Crawl Space)
There are basically three methods to remove the radon from this area.
The crawl space can be depressurized by drawing the air out of the crawl space and exhausting it to the outside.
Another option, though not highly recommended is to pressurize the crawl space with fresh air and dilute the radon gas to acceptable levels.
Lastly, and the most efficient and effective is to install a Sub Membrane Radon Depressurization System over the earthen floor.
Home and Building Interior Air Ventilation Systems
Although not highly recommended, through increasing the ventilation rate in your home using Heat Recovery Ventilation you can dilute the radon concentration to acceptable levels.
The radon reduction systems described above are the most commonly used. There are several other methods or modifications which may include combinations of the above systems. A radon reduction system should be installed by a competent person who has the skills and understanding of radon mitigation. However, there are several "Do It Yourself" manuals available that offer step by step radon mitigation system installation instructions that if followed properly can achieve good results.
Health Canada recommendations for mitigation are as follows:
radon levels between 200 Bq/m3 and 600 Bq/m3 should be mitigated within two years
radon levels above 600 Bq/m3 should be mitigated within one year