Mitigation (Radon Reduction)

Mitigation service refers to the method of reducing radon levels in homes and is undertaken in different ways depending upon the style of home. (Bungalow, full basement, crawlspace, slab on grade, etc). The average cost to mitigate homes in Canada is $3,000.00.

The theory of lowering radon in homes is the same for all home types. Create a lower air/radon pressure below the home such that radon will take that lower pressure route to the exterior rather than enter the home.

1.Sub-Slab Depressurization (SSD):

This refers to the method of drilling a hole into the concrete floor, creating an air pocket below (by removing material) and connecting a continuously operating fan and piping to the hole thus generating vacuum (negative air pressure) under the floor. The piping is then routed to the exterior of the home via a suitable route and discharge point.

This method works as well as the granular material below the floor is porous and draws air through easily, to the suction point. Depending on the diagnostics, sometimes more than one suction point may be needed, a higher sucking (noisier fan) or a directional boring method employed to assist air migration below the floor.

Master Radon has developed a directional boring method/tool which assists greatly in creating suitable air movement.

2. Indoor Sump Pit/Weeping Tile Depressurization:

Homes that have weeping tiles can sometimes be mitigated by drawing air from a sump pit location. This effectively draws air from the weeping tile and from below the concrete slab. 

In many homes this sump pit location is at the point where the sewer and water enter the home which in some cases (if the grade is poor outside the home or sunken badly under a step) cause cold air to be drawn from the surface to the sump pit potentially causing the water line to freeze. There is a remedy for this but it is desirable to determine there is a problem before a water line freezes. To that end Master Radon installs a switch on the system which will turn the fan off if the temperature drops too low in the pit and therefore warning the homeowner that there might be a problem. The simple remedy to the problem is to fill any air pathways with dry fine sand to block the cold air from traveling to the sump pit.

If this is something you need help with, Master Radon will be happy to provide this service should it be needed in a rare case.

One down side to this method is that the sump pit is often in a finished room of the home and a radon system is not aesthetically pleasing and does generate some noise pollution.

3. Outdoor Sump Pit/ Weeping Tile Depressurization:

This method effectively does the same thing as a sump pit depressurization system without the need for the fan to be visible indoors. This is another C-NRPP approved method which works extremely well.

A hole is made into the soil at a suitable location next to the home outdoors. The weeping tile is located, cleaned off and a pipe is connected directly to the weeping tile below ground (at footing height) with a fan installed on top of the pipe outdoors.

This method is a bit more work and requires an electrician to wire and permit an exterior disconnect switch near the fan (as per code).

Besides removing the visible fan from the basement, it also serves to draw possible cold air away from the sump pit, preventing the possibility of a frozen water line.

Master Radon has developed some very specialized tools and methods to do this work. These systems work extremely well and the fans are warrantied for 5 years to be installed either indoors or outdoors.

4. Sub-Membrane Depressurization (SMD):

This method is commonly used in crawlspaces which do not have a concrete floor. The method involves installing a heavy duty cross laminated poly membrane onto the floor of the crawl and up the wall of the crawlspace. The membrane must be sealed well at seams and at the perimeter. The suction point is then from below the poly membrane and vented out of the home to an acceptable location.

This method is very effective but rather costly (due to the material cost and high labour needed) compared to other methods.

5. Crawlspace Depressurization:

This method under certain circumstances (such as no furnace or furnace ductwork installed in the crawlspace) can be utilized at a very reasonable cost and can be very effective.

NOTE: Other methods or combination of methods might also be utilized depending on diagnostics.