Comments on: 3 Reasons Your Crawl Space Has High Humidity & Grows Stuff

By: Janet Carr

Janet Carr — Tue, 23 Sep 2014 00:42:28 +0000

Who is the best company to
Who is the best company to call to end the problem of mold, some termites in my crawlspace. It is an all brick home with the highest part of the crawlspace about 6 feet which then goes down to about 3 feet.

By: Judy H

Judy H — Thu, 03 Jul 2014 03:42:53 +0000

Okay, my crawlspace is sloped
Okay, my crawlspace is sloped. Why is that? Also having moisture problems – never had when I lived there..Of course I had a heat vent going to the crawlspace. I do not live there now, and have the dehumidifier going in the main house (700sf) all the time…still seems moist. Worried about keeping that building healthy!

By: David Butler

David Butler — Sat, 28 Jun 2014 22:05:28 +0000

@Ron, without an inspection,
@Ron, without an inspection, there's no way to know how water got inside that duct.

Assuming it's a supply duct, one possibility is that the outer cover for the flex was not properly sealed at each end, thus allowing humid air from the crawl to enter the space between outer and inner duct liner, bypassing the duct insulation. Any humid air that reaches the cold inner liner will naturally condense.

It's also possible that the condensate tray is clogged and water is backing up into the duct, in which case the water would be inside the inner liner, not between the inner and outer liner.

Or a plumbing leak could make its way into the duct.

By: Ron

Ron — Sat, 28 Jun 2014 18:13:41 +0000

Yesterday (6/27/14) we
Yesterday (6/27/14) we discovered a water leak/pin hole size appx.3' from our water heater and appx. 6'away from the HVAC unit in the crawl space.(Typical crawl space, sloped ground from 18" to 4'-5' from end to end). During the repair process I noticed the insulation around the area of the leak sagging from the water weight, which is normal. However, the insulation in a very large space around the HVAC area, but not near the leak, was also saturated. As I inspected the area closer, I saw a light grayish stain on the floor joist and support beam also in these areas. I figured this was the beginning of mold or mildew forming. I was barely able to get a sample onto my fingers and inspect it.
The HVAC unit has a flex duct appx. 6' in length connected to the forced air side of the a/c and was sagging with water. I poked 3 holes with a small blade of my knife to drain it. The orginal metal duct appx. 18'-24" dia. was disconnected when the new HVAC unit was installed and relocated appx. 6' away. This is where the flex duct was added.
Can improper installation of the HVAC unit cause some of the above problems ? I may need get an HVAC tech. to repair this as well. The units are only 4yrs.old.
What steps do you reccomend I take to resolve the problem(s)?
Great article and information!
Thanks for your time and attention to my interest.

By: Adele K

Adele K — Thu, 22 May 2014 18:57:47 +0000

House I'm buying has wood
House I'm buying has wood moisture reading of 25.I'm a widow and no nothing about crawl spaces..I've been told needs new vapor barrier.Don't want to spend thousands can't afford it..Any suggestions. ..Is that level dangerous to my health?

By: DGriff

DGriff — Wed, 19 Mar 2014 06:38:55 +0000

Is a crawl space supposed to
Is a crawl space supposed to be moist at all? I don't have standing water but it is a bit moist. I live in california

By: Holly

Holly — Sun, 18 Nov 2012 23:35:54 +0000

What do you suggest for a
What do you suggest for a house in a flood zone that requires flood vents? The crawl space needs to allow the flood waters to run through, in the case of a flood. This just occurred with hurricane Sandy. We are thinking of adding a Tjernlund UnderAire Crawl Space Ventilator to help air it out.

By: David Butler

David Butler — Tue, 17 May 2011 00:25:15 +0000

I just posted an updated
I just posted an updated version of my above comment in LinkedIn:
http://linkd.in/iYVAKS 

I included a link to Craig DeWitt’s landmark paper from 2003 ASHRAE Journal. He was among the first to make the argument for closed crawls. His paper goes into some depth on the RH issue and wood moisture. In particular, 70% relative humidity is probably not the best reference for evaluating whether a crawl space is at risk for mold. I encourage everyone who deals with crawl spaces to read this paper.

By: Elaine

Elaine — Wed, 11 May 2011 03:33:12 +0000

Awesome explanation of these
Awesome explanation of these very common problems in Hot 'Lanta. I would like to formally request that this article be sent to my condo association. Nice kayaks. :-)

By: James Groman

James Groman — Wed, 11 May 2011 01:37:53 +0000

I have sealed the crawlspace
I have sealed the crawlspace vents in a 90 yr old house, installed a vapor barrier, and have a dehumidifier running. The mold seems to have stopped growing, so what is the best method of mold remediation, and is there treatment I can apply to prevent future growth