Lack of ventilation and wet conditions in crawlspace

Home Inspector with Clayton Inspection Service, Inc.

Two of the worst things you want to see in a crawlspace, poor ventilation, AND wet conditions. The house I inspected yesterday, had three things going against it.

1. Poor ventilation. The house was built about 1 block too low, so most of the vents were not about the ground. Not only did they not install enough vents around the house, but where there were vents, they managed to effectively block the air flow by building little boxes around the vents. Of course the vent wells were full of leaves, mulch, grass clippings and who knows what else to help block the air flow.

2. The slope of the land around the house directed any water toward the foundation, instead of away from it. There were low spots in many areas, so water just collected next to the foundation walls. The gutters hadn't been cleaned in a decade or so, and the downspouts just dumped the waetr right next to the foundation, instead of flowing away from the house.

3. No vapor barrier on the ground in the crawlspace. Water vapor from the saturated earth under the house just condenses on the wood framing.


So the result was a bunch of fungus growth on almost all of the floor joists along the from of the house. Many of the joists were so rotted the wood was brittle. Termites had also found their way into the house and were enjoying the free buffet.

I was doing the inspection for a couple that are renting the house and thinking of buying it. Now faced with a pretty costly repair, the seller will either have to reduce the price of the house, do the needed repairs, or they will be looking for another house to buy (their comments).

Here are the photos of the fungus growth and the rotted wood. 



This entry hasn't been re-blogged:

Re-Blogged By Re-Blogged At
Property Inspection Discussion
Home Inspectors across the country
First Time Homebuyer
Tennessee Home and Building Inspectors
dry rot
damaged joist

Post a Comment
Spam prevention
Spam prevention
Show All Comments
Jean Powers
Kane & Associates call 510.908.9002 - Alameda, CA
CRS,e-PRO,HAFA,SFR Broker, Northern California

Thanks for the great information. The photos are good too

Nov 21, 2008 01:13 PM #1
Mike Klijanowicz
Cummings & Co. Realtors - Perry Hall, MD
Associate Broker @ Cummings & Co. Realtors

Thanks for sharing the pics and your tips here.  This is something very important for ALL of us to remember...

Nov 21, 2008 01:13 PM #2
Connie Wilhelm Zulu
Peak Realty Ltd., Brokerage - Saint Marys, ON

great pic thanks for sharing

Nov 21, 2008 01:37 PM #3
James Quarello
JRV Home Inspection Services, LLC - Wallingford, CT
Connecticut Home Inspector

Jack, I would agree with everything except the lack of vents. It has been discovered that in some climates vents actually cause condensation and thus rot. It sounds like this home had many problems that led to the problems you have discussed.

Nov 24, 2008 11:24 PM #4
Jack Feldmann
Clayton Inspection Service, Inc. - Knoxville, TN


In this area, the lack of a vapor barrier is kind of a kiss of death. Crawlspaces here really need lots of ventilation, or NONE, and have the sealed crawlspace technology installed. 

Nov 25, 2008 12:37 AM #5
Robert Dirienzo
HABITEC Home and Building Inspections, LLC - Franklin, TN
Home Inspections - Nashville TN

Hi Jack.  Nice post. 

I'm in the camp to vent the crawl space.  I've seen the unvented type and have not been favorably impressed.  Vent them, keep the vents open year round, and keep the vents clear.  Put a solid moisture barrier on the ground inside the crawl such that it is attached to the walls and piers and overlaps at the seems.  Then grade to keep the runoff away.  No sprinkler heads within 18" of the foundation.  And keep a close eye on the water management system.



Comments in this blog posting are the intellectual property of Richard Acree, President, HABITEC Home and Building Inspections, LLC, and contributing members of the Active Rain Real Estate network, and are intended to educate and otherwise assist home owners, sellers and buyers, building owners, sellers and buyers, realtors, real estate investors, property managers, and lenders in the process of owning, buying or selling homes or commercial buildings.  HABITEC is a residential (home) and commercial building inspection company serving Middle Tennessee including Nashville, Brentwood, Franklin, Murfreesboro, Smyrna, Mt. Juliet, Hendersonville, Dickson, Belle Meade, Columbia, Spring Hill and more!  In addition to building inspections HABITEC offers Environmental Services for mold assessments, radon testing and water quality analysis.  Additional information about HABITEC can be found on our website at, or call 615-376-2753. 

Richard Acree is the author of the HABITEC Home and Building Inspections Blog and founder of the ActiveRain Group Tennessee Home and Building Inspectors.  All are welcome to join and see more blogs like this one.

Dec 02, 2008 01:01 PM #6
Jacques Mountain
Dream Home Inspections/203K Consultant - Fayetteville, GA
Inspector/203K Consultant

Great post and I too am in favor of the vented crawlspace.

Richard, I appreciate the tip about having sprinklers within 18"inches of the foundation!!

Dec 03, 2008 04:18 PM #7
Frank Torre
Torre Inspection Service, LLC 888-202-8869 - Hicksville, NY

Hi Jack, another great post I was checking a  attic with poor ventilation and ran into a similar situation.

Dec 04, 2008 06:30 AM #8
Post a Comment
Spam prevention
Show All Comments

What's the reason you're reporting this blog entry?

Are you sure you want to report this blog entry as spam?


Jack Feldmann

Ask me a question
Spam prevention