on 6/17/2008 11:05 PM aemeijers said the following:
Edwin Pawlowski wrote:
wrote in message
...

On Jun 17, 8:37 pm, Albert wrote:
I was looking on the Internet for some Window Wells to prevent dirt
from piling up near my crawl space vents. Then I see something like
this on the Internet suggesting that the thinking is now to seal the
vents to save on energy and keep out moisture?

http://www.basementsystems.com/crawl...oducts/crawlsp...


What is recommended, to seal the crawl space vents or leave them open
for air flow?

Ventilation is very important. It is much better to properly insulate
the floor joists in the crawl space than to seal off the vents. That
is what they are there for.

************************************************

Curious, did you read the web page posted? What are you basing your
statements on?

It states:
If Crawl Space Ventilation Doesn't Work, What's the Solution?
There is an informative article by Advanced Energy, a national
resource who focuses on applied building science, on venting crawl
spaces entitled, "To Vent or Not to Vent." [Download PDF]
Crawl space encapsulation is the solution! Seal the crawl space with
a vapor barrier, sealer the crawl space vents with vent covers, seal
any gaps or holes to the outside, seal the crawl space door - seal it
up as tight as possible.






Do you think it is possible that the thinking has changed and
engineering is proving the ventilation method is wrong?


Most modern houses I've seen with crawls don't even HAVE vents. When
did Visqueen and similar become widely available? Late 1950s or so,
IIRC? In the old days, there was no practical method to seal the dirt
with a vapor barrier, and if you had a lot of ground moisture (due to
climate, high water table, bad grading and poor footer drainage, etc),
venting was the only way to keep it halfway dried out. A hundred years
of tradition takes a few decades to fade away. Remember, in most parts
of the country, concrete floors in basements (outside of big cities)
didn't get common till the 20s and 30s. Of course back then, the
cellar entrance was usually outside-only.

--
aem sends...

I agree with you there. If the dirt in the crawl space is covered with a
moisture barrier, then the vents can be sealed, but if the dirt
constantly gets wet from the conditions you noted, then the water vapor
is trapped inside, possibly causing rot of the wood above.

--

Bill
In Hamptonburgh, NY
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