How much moisture comes from crawlspace soil?

[Ben J. Gromicko]

How much moisture comes from the soil in a crawlspace with an exposed dirt floor?

[David A. Andersen]

Where do you live?

[Ben J. Gromicko]

Originally Posted by dandersen

Where do you live?

So the answer is related to where you live?
Let's say TEXAS.

[Jae Williams]

Vented or non-vented. Any problems with the stem wall? Downspouts?

[Jae Williams]

I answered before your second post. Let's say Ohio Valley. We get rain now and then...

[Bruce A. King]

And even more related to the particular lot, drainage etc.
It varies from no problem all the way to major issue around here.

[Jeffery L. Haynes]

Depends of the type soil, amount of foundation proofing, topographical conditions, number of vents........whether etc.

Jeff

[Ben J. Gromicko]

Originally Posted by jwilliams4

I answered before your second post. Let's say Ohio Valley. We get rain now and then...

Ya'll may be missing the point.
The question is "How much moisture comes from the ground?" In gallons or pounds.

I have found an answer of 100 pounds (12.2 gallons) of water can come from the exposed crawlspace ground per day per 1,000 square feet of a house. (averages)

Agree? Or do you have another calculation?

[Joe Funderburk, CMI]

Originally Posted by bgromicko

I have found an answer of 100 pounds (12.2 gallons) of water can come from the ground per day per 1,000 square feet of a house. (averages)

I have no idea, but don't doubt the figure you quote. Crawl spaces around here are like rain forests this time of year. I often feel like I need one of these...

[Christopher Currins]

Originally Posted by bgromicko

Ya'll may be missing the point.
The question is "How much moisture comes from the ground?" In gallons or pounds.

I have found an answer of 100 pounds (12.2 gallons) of water can come from the exposed crawlspace ground per day per 1,000 square feet of a house. (averages)

"Can", which relates to all of the above answers.

[Michael Larson]

Originally Posted by bgromicko

Ya'll may be missing the point.
The question is "How much moisture comes from the ground?" In gallons or pounds.

I have found an answer of 100 pounds (12.2 gallons) of water can come from the exposed crawlspace ground per day per 1,000 square feet of a house. (averages)

Agree? Or do you have another calculation?

What kind of soil?

Gravel
Bedrock
Sand
Clay

[Jae Williams]

Y'all may be missing the point, Ben.

You gave an illustration with the word "can"...

but is arbitrary. It just depends on many different factors and different areas of the USandA.

[Ben J. Gromicko]

Really?
Oy.
I thought that water evaporates at a rate that is (on average) constant.

So,
Let's take where you live... Do you know how much water can evaporate from the ground - in relation to your zip code?

Jae, Ohio, what's the rate?
Michael, MN, what's the rate?
Currins, from IL, what's your rate?

[Michael Larson]

Ben I can take you to at least 5 different soil types with 30 minutes of my location.

What are you going for.

Your number is very high IMHO.

Where is it from?

[Ben J. Gromicko]

Doing research for the next InterNACHI course...

Several studies have considered how a crawl space can
contribute to the moisture level in a building. Britton
reported an average evaporation rate of 12.1
gal/1000 ft2/day (490 g/m2/day or 0.10 lb/ft2/day).
But this is old data. (R.R. Britton, Crawlspaces and their effects on dwellings.)


I'm looking for new research.

Moist air from the crawlspace is often the most significant source of moisture entering a home.




I've also read - If soil is damp in a 1,400 square foot crawl space, as much as 20 gallons of water a day can evaporate into the air.

Dan Morrision from GreenBuildingAdvisor, "About a gal. per 44 sq. ft.) evaporate from bare soil in a crawl space"