Water in crawl space after HEAVY rains

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Old 01-21-16, 08:53 PM
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Water in crawl space after HEAVY rains

We are on level ground in Oregon. I lifted the hatch and found 2 inches of water below. 3 days later is is gone Never noticed this problem before. I will crawl around and gather all the torn and shredded vapor barrier as well as fallen insulation and haul away. Will seal any obvious cracks in the blocks or footings. Also spray something (any suggestions) for mold or mildew, if I see some.

A friend said "that is plenty for now. Leave it alone to dry out until June or July" ....before I get new 6 mil plastic and re-do the vapor barrier.

Sound OK?

Thank you.........
 
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Old 01-21-16, 09:43 PM
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Getting rid of the vapor barrier so the ground can dry out is a good idea. Generally you want the ground to slope away from the house 1" per foot for the first 10'. You would have downspouts long enough to send water away. Gutters should be clean, not overflowing and dripping right off the roof next to the house. All basic stuff. If any one of those things inst the case at your place, it's not surprising you have a problem.
 
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Old 01-28-16, 06:53 AM
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Licensed home inspector here yesterday..went under the house and did not find anything too bad. Small cracks where blocks meet footing, condensation on ABS drain lines and torn vapor barrier.

He thought water was coming in via foundation vents which have soil too close to them. Recommended re-grading and metal vent wells in front of each foundation vent. No mold/mildew.
 
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Old 02-06-16, 02:00 PM
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I hired a small handyman to crawl around under the house to remove torn vapor barrier, trash from new duct work install (contractor told me they took it all...liar) and loose insulation that fell from under the sub floor as it got wet from condensation.

A large firm that advertises on TV as foundation/waterproofing contractors in OR and WA is coming in a week to give us a free inspection and written estimate to fix our crawlspace. Should be interesting. Pretty sure we do not want encapsulation with sealed foundation vents and other improvements. I am leaning towards new 8 mil or better Visqueen; patching any cracks the home inspector found; sealing rim joists and replacing the 1993 unfaced insulation now installed under the sub floor. (I am a dunce about insulation...Should it be spray foam? or batts with a foil facing or......??

Any thoughts would be appreciated.
 
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Old 02-16-16, 07:37 AM
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Large firm here yesterday. Likes only encapsulation. $26,000.00 to do it. GI2
 
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Old 02-16-16, 08:27 AM
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How about some pictures of the outside so we can see what your seeing.
Water proofing starts outside not inside.
 
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Old 02-16-16, 11:39 AM
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a good 6 mil VB installed correctly shouldn't cost more than 4-5 grand
 
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Old 02-19-16, 05:34 PM
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airman....hope that was in jest. I am having this done tomorrow....$1200.00, parts and labor

joe.....too inept to post pictures. I do realize sealing from the outside is the way to go, but it is not practical to do this. I have not noticed this in the 10 years we have been here. The two people who did crawl did not report seeing a bathtub ring...so I am pretty sure this happened after two weeks of a steady light rain (maybe 7 inches, total)......followed by 5 inches of rain in 5 days.
 
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Old 02-28-16, 07:46 AM
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OK....done yesterday, a week late. Think it was a good job. We shall see.

QUESTION, please. I have tried Google for a formula to tell me how many gallons had entered our 2000 sq. ft. crawlspace when it peaked out at two inches. I am not good at math or estimating. I came up with 2492 gallons. Hope this was wrong. Will some one provide me with the correct answer.

Thank you in advance......
 
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Old 02-28-16, 07:59 AM
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2000 sq ft and water was 2" deep? I think you are right.
 
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Old 02-28-16, 10:05 AM
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So....that is equal to me putting my garden hose under the house and adding 8 gpm for 5.1 hours. Hopefully this was a once in a lifetime event...... as it rained so much and probably entered the crawlspace via one or more...foundation vents. There should be 6 inches of space between outside soil level and the bottom of the vent, I have been reading. Sorry to say 2-3 inches is the figure at our casa.

I will try and regrade the soil lower and away from the vents. There is a two foot roof overhang, but I guess it was not enough as water pooled, rose up and went thru the vents. (maybe)......

I did find some vent space "window wells" which might help for a downpour...but it said that they cut off ventilation to the crawlspace. Anyone have these ?
 
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Old 02-28-16, 12:44 PM
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It doesn't take long for a flood of runoff from a heavy rain to bring in that much water. Your basement may be 2000 sq ft but if runoff is the combined rainfall from your roof, or your yard, or from the 40 acre hillside behind the house... now you're talking about a big area and a lot of water in a hurry.

I have a friend whose basement was recently flooded because of a new addition that is underway in his neighborhood. Trees were ripped out, grass scraped off, etc. Its a big construction site. Well apparently they have little or no flood control, so a lot of that water overflowed onto his property, flooding his basement. Now the legal battle begins. City administrator said tough luck. I'm guessing his legal fees will exceed the damage done.
 
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Old 04-11-16, 07:58 AM
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UPDATE.....I asked some local building contractors about my situation. Told them I could find no evidence of water intrusion via foundation vents or cracks in the foundation. Two thought that the excessive rains (6.5 inches in 6 days) had gone down our red clay soil to such a degree that it went past the foundation...went sideways into the crawlspace...and came up.

They said red clay is, as we all know, hard in the summer. But, during the winter rains it is actually very porous and water could move as described above.

I will ask some local well drillers, soil engineers and building contractors about this.

Any red clay experts out there who can chip in ?
 
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Old 05-05-16, 10:40 AM
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Talked to more contractors, engineers, well drillers. Nothing really conclusive emerged. Don't think they know a lot about red clay. One thought the water table had risen and perked up under the foundation and into the crawlspace...(well drillers log from 1993 said static water level was at 35 feet) ?? Two thought water had worked its way down thru the red clay and seeped into the crawlspace. A couple thought that the "water thru the foundation vents" theory was the correct answer.

Any red clay experts out there........?
 
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Old 03-24-17, 08:24 AM
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OK, here is the latest.....This Jan 2017 I found 4 inches of water after LOTS of rain and snow. My two 1/4 HP utility pumps got most of the water out in 5-6 days. No water intrusion since... and only minor rain/showers. I am taking the approach that water saturated the red clay, went past the foundation and wicked up into the crawlspace. Last year... soil around the home was regraded away from the foundation vents... and metal vent wells were installed.

Home Inspector, HVAC techs and 2 handymen have gone into crawlspace in the last year and reported nothing obvious or out of place. Fiberglass R21 batts between the joists were dry. I never did go into the crawl space...don't like spiders. I hired two persons to pull out the old vapor barrier and put in new.

After chatting with many builders we have discarded french/interceptor drain plans, both outside the home and in the crawlspace. No sump pumps inside or out. We are going to leave things as is and see if more water comes in. If so, it will be pumped away to the back 40. I have water alarms in the crawl space and pumps close by. Might pull up and discard the 6mil vapor barrier. (?)
There will be a contractor here one of these days to use his 100 foot inspection camera to check the gutters and drain line to the back 40....as well as from the pool patio.

This last winter was the worst for rain/snow in 30+ years, say the old timers.

Thanks for all your comments.
 
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