Drying out a crawl space

Climberman

Climberman

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My crawl space is damp. Humidity readings around 70% and a couple of my joists are starting to get the bleaching effect before mold growth.

I had a foundation guy come by and look at it. He recommended a drain around the perimeter of the foundation wall with a sump pump and a new vapor barrier or encapsulation.

My house is on a side slope. So I am wondering if the sump pump is necessary. I am also wondering how much it may help to excavate the uphill foundation wall and coat it with waterproofing.

Anyone have any experience with these matters?
 
Have to see the lay of the land but sump pump may not be necessary. If you’re gonna put In A foundation drain around the outside you may as well roll on some waterproofing when the hole is open if the house has never been done. Usually a good drain around the outside and if the grade is right inside you can put a drain in to catch anything on the inside and some plastic and you’re good to go
 
Climberman said:
My crawl space is damp. Humidity readings around 70% and a couple of my joists are starting to get the bleaching effect before mold growth.

I had a foundation guy come by and look at it. He recommended a drain around the perimeter of the foundation wall with a sump pump and a new vapor barrier or encapsulation.

My house is on a side slope. So I am wondering if the sump pump is necessary. I am also wondering how much it may help to excavate the uphill foundation wall and coat it with waterproofing.

Anyone have any experience with these matters?
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Can you regrade around in front of the house to direct the water flow away? All your gutters working on front side of house and piped away to not dump any more water in front. If you can not take care of where the moisture is coming from and redirect it the other things are kind of bandaids and may or may not help.
 
4 years ago, i lined our crawl space floor with a double layer of 6 mil plastic
and hooked up a cheap floor fan that runs all the time.

this year's inspection reading was 42%.
 
The uphill side is on the side of the house and is tough to grade due to a number of factors but I will try to improve it and the piping away of the roof gutters.

The drain he wants to install is in the crawl space and not outside the crawlspace.

One other thing I am trying to decide is how much water is traveling through the foundation wall and joints vs how much is traveling under the wall through the soil. Not sure.
 
We had an issue with water in our crawlspace. One end was walk in, other end sloped up to just a couple feet. The neighboring 3 yards all flowed towards ours.

humidity readings were 80% many days.

I built a 1-1.5 foot berm on the side of the house to redirect any water away from the house, had someone lay new vapor barrier and seal the vents, I installed a small dehumidifier that we already had from a previous apartment. With all that the humidity easily stayed below 50%.
 
I don't want to insult anyone on this board, but I haven't found much integrity in the foundation and crawl space business. It seems that when you call one of these guys, the solution to your problem is whatever they are selling. I had some moisture. I called three guys and got three completely different solutions, estimates from $4000 to $14,000. I then called an independent professional engineer with a construction engineering degree and a state license, who does nothing but inspect and report--he's not trying to sell me anything. For $350 and an hour of his time, he gave me a report with his license number on it, detailing what was necessary. The changes he recommended were done for less than $2000. I see that you are in Raleigh and the guy I used is in Raleigh, so if you PM me I'll provide his contact info.
 
I had a completely different issue then you....my crawlspace was dry until i had a new hvac unit installed and new duct work. I guess the old duct was dumping enough cool air into the crawlspace to keep the humidity down. I was getting condensation on the new duct....my exterminator does crawlspace encapsulation and he came and gave me a quote and went over exactly what i needed to do and gave me the option to pick and choose what I wanted to do myself to help save money and even offered to order the materials for me through his supplier if it was cheaper....I did everything but lay the plastic and only spent 2200 instead of 5k
 
I had to do pretty much the whole enchilada…

French drain along foundation interior
Sump pump and pit
New vapor barrier (didn’t go up the foundation walls, just too much work)
Sealed foundation vents
Monster dehumidifier that dumps into the same sump as the French drain

At this moment, we’re at 45% down there (I have a remote monitor).
 
In my younger days, I used to do this kind of work. If you decide to DIY it, the job is much easier approached from the outside. Grade changes, French drains along the foundation walls, and automatic vents can make a big difference. As has been said above, waterproofing your foundation walls below grade when putting the French drain in is a good idea. Also, there are membranes that are made for foundation walls that can be used that will wick water to the drain. Most crawlspace moisture issues can be solved with these approaches and it is less labor and cheaper. Also, I would wait for the crawlspace to dry out before putting down new poly.
 
Terminix wanted to encapsulate my crawlspace, no thanks. I got a few quotes and went with Triangle Crawlspace.

Easy to setup a site survey at no cost, itemized quote same day.100% professional, company name on the truck, crew called ahead to let us know they are on the way. Crew had proper safety gear to do the job properly, They kept me informed on the progress. Replaced builders 4 mil vapor barrier with new 12 mil and Zoeller sump pump.

trianglecrawlspacesolutions.com

Triangle Crawl Space Solutions

Triangle Crawl Space Solutions eliminates moisture from your crawl space. We install and replace vapor barriers, are a Santa Fe Certified installer for dehumidifiers and can help remove mold. If your crawl space is wet and musty, give us a call. From sump pumps, drainage solutions or replacing insu
trianglecrawlspacesolutions.com trianglecrawlspacesolutions.com

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when we encapsulated ours we took down all the old insulation and insulated the exterior walls, there is a vent off the plenum to condition the crawlspace, and in theory we have" heated " floors in the winter.. once the area dried out I vacuumed off any mold spores and vented the exhaust of the vacuum directly to the outside
 
I want to run ozone for a month in my encapsulated crawlspace, wife is of the opinion that nothing bad happens below 50% humidity anyway.
 
One other thing to check that might be free is your current foundation drains are they open where they can drain freely? I had one that a small section got crushed down and it was causing water to backup in it and come threw basement wall.
 
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There really is only one way to dry up a crawl space.

Eliminate the foundation vents. (stupid building regulations) You live in the south.
Seal the space up tight and condition it. Until you do that you will continue to have damp or wet crawl spaces.
 
But maybe make sure that your gas furnace under the house has a way to get air before you seal things up too tight.
 
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