My House lies along the path of Missoula Floods erosion of land about 110,000 years ago, in a dramatic stage of erosion that formed The Columbia River Gorge,
For too many years of my life, I was aware of radon levels persistently above ten picocuries per liter in my home. EPA recommends: Fix your home if your radon level is 4 picocuries per liter (pCi/L) or higher.
I have at last achieved the needed fix, by novel means employing the natural drive of chimney effect. I think this is a really big deal. By my example, every home could be fixed with modest up-front cost and without any operating cost or degraded home value by zip code or neighborhood. This must be good news, not bad, for all of us, including abatement contractors.
My quest for passive control of radon began with fitting two 4" warm air pipes sealed full-length, between my crawl space and my attic. There is excess space in a bathroom wet wall; put some of that to use. There will be significant chimney-effect drive of air flow when the pipe(s) are completed through-roof.
I expected to make this work someday, avoiding a radon pump if possible. How big is the needed pipe? Maybe 6" diameter? The two 4" pipes equal one 6" pipe, and that much fits in the wall. If one is enough, the other might serve as an ample wiring conduit between crawl space and attic.
Minimize wet wall thickness above a tiled shelf. With an epoxied-on copper band, avoid reliance on caulk in sealing the new tub behind backer board and tile. Read more about the tub install in this blog post of October 2013: Insulate Exterior Wall of a Bathtub or Shower
For years then, the pipes did nothing, not connected through-roof and not collecting from the soil of the crawl space. House radon levels were unchanged.
Dig this trench in the dry, hard dirt of my crawl space.
Hereafter I will own an over-abundance of these tubs. I disposed this many tubs of dirt, a carload, twice.
Use landscape cloth to separate collection ducting from the dirt.
The gravel fill is crushed quarter-minus.
At both bottom and top of 4" ducting, engage 4" warm air pipes with a spun-aluminum roof penetration adapter. In the crawl space the adapter flat face is upward. A wide circle of two-sided butyl tape bonds the adapter to the Americover Goldentouch 16 mm scrim-reinforced plastic sheeting, the central element of my conditioned crawlspace. On the roof, the adapter makes a better water barrier under an additional layer of shingles. A roof cap just blocks rainfall.
Here is another use of rope-form putty weatherstripping.
There has been a large binge of benefit from the clean ground cover for plumbing, wiring and heating of the grand kitchen remodel off in the far distance at left here.