Sealed Or Open Crawl Space?

J.C. Leonard

I have been hearing a lot of talk about sealing as opposed to venting crawl spaces. I am building in Charleston, SC where the humidity is insane. Everything I have read leads me to belive this is the way to go, but I always like to try and get as much info as possible when trying something new. I am considering a seal crawl retro fit on two of my house that already have bat insulation in the floor joist. Everything i have seen in regards to sealing a crawl has no bat insulation. If i decide to seal should I remove the batting?
I you guys don't mind give me your thoughts.
Thanks, Chris

stacker

in all my years as in this business,i have never seen a sealed crawl space.but that is not to say they arent there.hell ive never seen a baby pigeon either.but it seems in the last couple years here where i live,the code is to install more crawl space vents and not less.i laid the foundation on this house two years ago and the builder brought out all these vents,around 18.i asked him if he was nuts and he told me that,that was the number of vents the city inspector had required for the size of house.
i belive a crawl space does need ventalation but not overkill

__________________
life is short,do your masonry naked!!
http://ok.local.yahoo.biz/knabemasonry/index.html

Dustball

This is interesting, based on tests in NC-

http://www.energycodes.gov/news/2003...dfs/warren.pdf

I would lean towards non-vented crawlspaces.

Teetorbilt

My home (outside of Hickory, NC) is circa 1973, brick, non-vented, batt ins. between joists, has never shown any crawl space problems.

BTW, the average ground temp. there is 53* the same as Bordeaux, FR so it also makes an excellent wine cellar.

__________________
You can't solve you're problems with the same level of thinking that created the problems.

Albert Einstein

Floordude

Vented crawl spaces must be vented on all 4 sides with adiquate crossflow, for them to not build humidity under the home.

Sealed and conditioned crawl spaces are best for hardwood flooring. With homes being built tighter and tighter, you have the ability to drastically have different humidity levels in the crawlspace, compared to the interior. A sealed and conditioned crawl space, maintains a moisture equalibrium balance in the subfloor and finished flooring. No chance of cupping, unless there is a massive leak.

Take outside air, say 70%@80º
Cool crawlspace say 70º.
Allow the air holding the 70%rH@80º, cool off to 70º what is the humidity level in the crawlspace

__________________
**Education is the key to success. Learn more, earn more.**
http://www.AustinFloorguy.com

J.C. Leonard

Thanks guys. I have an appt. mon. with a company that seals crawls. I will let yall know what he has to say as far as pros and cons go. I have almost made up mind though. Im pretty sure that I will be sealing all mine in the future.

Michaeljp86

The only sealed crawl Ive seen is under my grandmas trailer.

__________________
I am just a vessel from which genius flows -Homer Simpson

Global warming is a myth, like evolution and the metric system.

davy crockett

In one situation (with a h/o willing to try a new approach)I completely enveloped the floor and walls of a crawl with heavy plastic(6 mil) , taped all seems, removed all batt insulation ,closed all vents and sealed all air infiltration, insulated all exterior walls with solid R13 or so(foil backed) added a sump pump with pit and drain to exterior, installed a small dehumidifier draining to the sump pit and the cost was $6000.00 material and labor. It is now a comfortable,clean ,storage space.The floor upstairs is comfy to the touch,Vinyl and hardwood. 2-3 contractors before me sold this h/o vents/fans/auto fans,you name it and it wasn't cheap or dry (mucho moldy). Personally I think pulling air with 90% relative humidity into the house is dumb and the crawl spaces that I've been in where h/o forgot to open vents were actually drier. I think it's time we rethink this and I'm definitly open to learning if we can come up with a good system. Since I am a remodeler someone in the new construction end is gonna have to take the lead.