Inspector Told Us We Need $2500 Dehumidifier in Crawlspace

[elizabeth-s]

Hi Folks,
We have an old house with a damp crawlspace. We have installed vents and plastic to try to deal with the humidity, per the pest control company. We had our annual inspection and the inspector said we have fungus again (they treated the crawlspace for mold previously), and that the humidity will eventually attract termites. He said we need a dehumidifier that will cost $2500.

He kept stressing to us that if we don't do something about the humidity then the house will rot and termites will show up.

We are overwhelmed. Any thoughts?

[Darren]

Why is it humid? I'd look at the drainage around the house first. Is rain water being directed away from the house by the lay of the land and drains? IF not start their first.

Installing a humidifer before trying to fix the cause of the problem is wasted money IMO.

[Bearfootfarm]

After eliminating any drainage problems, you could look into installing "power vents" which are simply vents with fans to draw in outside air

[Roadking]

I simply use oscilatting fans to keep the air flow and the vents. No mildew or mold, and it has been WET this year.
Matt

[Curtis B]

Your inspector was right, moist wood will grow fungus and will attract termites. But the other posts are right in addressing the drainage. Unless you live in a swamp with proper ventilation you shouldn't have a problem. It may just be the area that I live, but I don't know anyone, and have never heard of anyone, that needed a dehumidifier in their crawlspace.

[Katey]

I'd go with the power venting idea. Just put fans blowing outward in half the ventilation openings you already have. There is no point in trying to dehumidify the whole great outdoors.

[TnAndy]

Originally Posted by Darren

Why is it humid? I'd look at the drainage around the house first. Is rain water being directed away from the house by the lay of the land and drains? IF not start their first.

Installing a humidifer before trying to fix the cause of the problem is wasted money IMO.

Exactamundo.....................

[Whisperwindkat]

We had the same problem in our house.We discovered that the rainwater cam off the back of the roof and instead of running away from the house ran under the back porch and down into the basement. So we cleaned out the mud from the basement and installed gutters along the back of the house. We also increased the slope away from the house by adding a french drain that sat a little higher than the previous dirt. The we installed a ceiling fan in the basement to circulate the air. There was simply no way to get under the whole house with plastic because much of the crawlspace is only inches above the ground. We make sure than we put out those termite sticks every year. The only time we have a problem now is if we have a long period of really high humidity in the summer time. At those times we do have a small portable dehumidifier that we will run in the basement. We don't have near the mildew problems that we have had in the past.

[7thswan]

Annual Inspection?

[cfabe]

I also agree with fixing the drainage problem and installing ventilation. I've never heard of a crawl space dehumidifier before. Something I have heard of is converting the crawl space to be a conditioned area by sealing the floor & walls with plastic and installing vents from your HVAC system down there.

[Randy Rooster]

I have a dehumdifier I bought at lowes in my crawl space. Bought it 2 years ago for about $130- I rigged a plastic drain pipe to it and run it every so often adn go down and check the crawl space every couple months. Works fine. I also have the foundation vents shut and insulated and heavy plastic covering the ground- its what is called a "sealed crawlspace".

Get a termite inspector out and an estimate to have your place treated. One treatment should last 5-10 years minimum.

[mnn2501]

Originally Posted by 7thswan

Annual Inspection?

I was wondering the same thing.

...

anyway, sounds like they need the sales, dehumidify a crawl space? no way, if its not sealed tight you're in effect dehumidifying the entire outdoors.
Listen to everyone else thats posted so far, you have a water problem, lets fix the problem, not the symptom.

[Harry Chickpea]

I've heard of using dehumidifiers down there. Unless they are set fairly high on the humidistat, the cost of the humidifier is nothing compared to the ongoing cost of the power to run it. Venting is good but can work against you as well on days when the crawlspace is cold and the outside humid. Drainage is the biggie.

FWIW, I have considered a metal duct from attic to crawlspace to combat the issue. Attic air is often hot and dry, and with a fan directing it to the crawlspace and then out, it could easily absorb moisture without the costs of a dehumidifier.

Also - A dehumidifier that will cost $2500? What is this, rip off the suckers month? You stick a cheap one down there, plumb it out, and if it rots away in five years, you buy another. $250 if you do the job yourself - considering piping and extras.

[fishhead]

I've heard that some people slope the ground away from the house and bury a thick plastic sheet a foot or so below the surface so that any rain gets directed away from the house.

It does sound like you've got to fix the source problem first. After that venting and exhausting the air with a relatively cheap attic fan should do the trick.

[agmantoo]

Here in NC we could be know as the mildew state! Up until recently the adhering to the building code for ventilation was very strict. Now there is an ongoing consideration for eliminating vents for crawl spaces altogether! Tests conducted by the state have verified that sealing the ground and the perimeter walls of the crawl space gives better control of moisture than what the code previously mandated. Already there are small businesses starting up to provide this service. My neighbor had her home done. It turned out very nice and it is a significant improvement to the home. Her under the home plumbing should never freeze, the floors are not cold and both her heating and cooling bills should be less. As others have stated there is no way I would install a dehumidifier nor would I want the increased utility bill. Have you ever noticed that homes with basements do not have vents? With a dry basement you do not need a dehumidifier either.
Here is what you need to consider doing
http://www.sealtightsolutions.com/
http://www.sealtightsolutions.com/cr...w-to-video.php

[Bearfootfarm]

Originally Posted by 7thswan
Annual Inspection?

I was wondering the same thing.

Sounds like a termite inspection to me

[TedH71]

Everyone has a dehumifider here in their basements in Kansas due to old houses not being built to code...everyone's basement leaked until the early 1980's..they figured out if they sealed the outside part of the basement then they wouldn't have mold problems. My wife's house was the only one not having mold problems when she went house shopping so she grabbed it even though it was bad on the inside (old flooring, inappropriate house design, etc).

[Jenn]

We have good grading and french drains for all the rain gutter run off. Heavy rains or if I overwater the plants right next to the uphill foundation there will be a trickle or small stream of water running through our crawl space. I have a fan set to come on for high temps (runs all summer long- in fact I turn it off in the day time when it'll be pulling in hotter air than it blows out) and high humidity. Now (70s daytime 50s night lately) it only comes on for a while after rain. The vents for incoming air are in the garage (we're on a slope- crawlspace has ceiling same as garage's and is uphill from it) and side of house. I also control by opening/closing garage door depending on how different outdoor air is from what I want he hosue temp over the crawlspace to be.

We are in muggy SE AL and I can't imagine a dehumidifier, aside from the heat pump AC in the house.

BTW we are on cinder blocks so the only termite risk is where the framing is close to grade on the uphill side- gotta watch how much mulch I lay down there. Leave a light on in the crawl space most times to prevent the termites from building tubes up the exposed cinder block columns and inspect for them occasionally.

[Wolf mom]

And how much of that $2500 is your pest control company going to get if he installs it? Ummm, a pest control company??? What about a building contractor?

Actually, the above advice sounds a lot better.

[Beeman]

I might have missed it buy I don't see where you are located. Every area is different and that difference would change any recommendations.
Where is the moisture coming from? Is it from poor drainage?