On Dec 11, 5:18*pm, "
wrote:
On Fri, 10 Dec 2010 01:43:42 -0800 (PST), harry wrote:
On Dec 9, 9:55 pm, mike wrote:
james wrote:
Even though there's a vapor barrier covering the dirt in my crawlspace,
there is still a strong musty smell in there that sometimes migrates
into living area. The soil under the vapor barrier is moist but not wet.
Since the vapor barrier is semi translucent, I can see condensation on
the underside of the vapor barrier at various air pockets around the
concrete footings.

Something could be brewing in those air pockets and is released into the
crawlspace via gaps between the vapor barrier and the wall or around the
posts.

Some contractors suggest installing a french drain in the crawlspace.. If
I do that, would it keep the top of the soil dry, or would water still
wick up the soil to the top? In other words, can water wick up from just
below where the french drain is (probably 2 feet deep), and make it to
the top of the soil?

What's the humidity under the house?
Where's the water coming from?
Is it wetter on one end of the house than the other?
Probably easier to divert water around the structure
than under it.
For a french drain to work you have to have an output
port lower than the water level you're trying to achieve.
If you have that, you can probably divert around.
Otherwise you need a sump pump. Digging holes outside
oughta be much easier/cheaper than trying to do it
underneath.

I'd see if the city has a hydrologist you can consult.

As for your question, I can't provide a reference, but as I recall,
the wicking distance is soil composition dependent and can
easily reach 9 feet. That was very surprising to me.- Hide quoted text -

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Wicking = capilliary action. *How high are trees? *They work by
capilliary action.

Trees are a lot more complicated than that. *They use a series of essentially
check-valves to get water to the top (similar to veins in people's legs). It's
not simple capillary action.



All depends on the size of the soil particles.
The only real solution is ventilation but then you may need to
insulate the floor of your house depending on your local climate.- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

There are no check valves in trees thhough there are i nviens. And if
there were how would it help as there is no pump/heart either?