Quote:
Originally Posted by S-F
?
You want to leave all but one sump hole open and suck air through the dirt beneath the slab?
OK
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Since those other sump holes have always had low radon levels,
I see no reason to seal them up now.
The Radon vac blower might suck a lot of air out of sump P2. Have to wait and see.
Just guessing, but I think there is a South to North underground water channel under the center of my house.
Water flows downhill from the south, only a couple of feet below my slab.
When it rains a lot, that water level comes up higher than my slab.
It tries to
float the house like a boat. The pressure cracks the slab.
During our first big basement flood, there was water shooting
up (about 6") out of dozens of small cracks in the floor!
That's a good indication of a lot of water pressure (and flow) under the slab.
I think the excess water pressure might have been caused by a poor design
of the S1 sump. It's a steel 'bucket' liner cemented into the slab.
There was only a few 1/4" holes in the bottom. The size limited the flow rate. (And mud blockages).
Had there been more holes (or larger holes) in the liner,
the water pressure under the slab would have been less.. Kinda like a sinking boat.
The slab damage was there, years before we moved in.
Once I saw the problem, I drilled a bunch of holes in the steel liner.
Edit:
Fan test results:
http://www.wpb-radon.com/radon_fan_p...nce.html#HP190
This is interesting, but, I really don't know what the 'volume' will be..