Can the piping for foundation drainage also be used if radon is found when the house is built?
Steve Young| Posted inGreen Building Techniqueson
I am going to have about 8 inch of gravel and in the gravel I am going to have draining piping. I will also be having insulation under the slab. I don’t think I will have radon, but just in case, I would like to simple attach a vent system to the drainage piping. I could have a t connection just as the drainage piping comes out from under the slab. If I have a problem with radon, I could then easily connect the vent line.
Does this sound like it will work?
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Replies
Steve,
It's best to keep your radon mitigation system totally separate from your drainage system. The reason is simple: usually, your drainage system runs to daylight (or a drywell or a sump). If you ever connect a radon exhaust fan to this system, it will pull air through the drain, undermining your attempt to depressurize the layer of crushed stone under your slab.
For more information on this issue, seeRadon mitigation with interior perimeter drains?
Martin,
I am planning a similar approach to Steve with a new house I am building. I am using pre-cast walls that will sit on an 8" bed of #8 gravel. The perimeter drain will run around the outside of the foundation and will tee and run under the basement wall into into a sump with a sealed lid and a pump attached to a liquid drain line that has a check valve (I read over the details you specified in the Fine Homebuilding article linked to your response to Steve.)
My question has to deal with what sort of piping to use for the perimeter drain that drains into the sump. I typically use flexible corrugated 4" black plastic pipe for a drain tile. However, should I be using PVC instead? I usually see PVC pictured for sub-slab radon venting. Given that I am running my foundation around the outside of the wall and not under a slab, is it still better to use PVC?