[Greenbuilding] Crawlspace

[Leslie Moyer]

I know the moisture barrier won't do anything for energy efficiency. But 
I was also going to have them insulate the perimeter walls at the same 
time, making the crawlspace semi-conditioned space.  I do not have 
moisture problems in the crawl space currently. The moisture problems 
I've had in the past have come from plumbing, not from any moisture 
entering from elsewhere. Our house sits on a knoll, I have good gutters 
& roof overhangs, etc., so no problems with rainwater or groundwater.

I know there are two schools of thought on this, but I didn't realize 
there was still debate about it.  I generally trust buildingscience.com 
and am making the decision based on the information they have there.

We just deeply renovated the house next door to us, tearing it down to 
the floor joists and studs, including ripping up all the subfloor.  It 
has a ventilated crawl space, though I don't know whether or not the 
previous owners kept the vents open, nor do I recall how good the air 
flow was. The floors were not insulated. The finished floors in there 
were carpet (mostly) and some vinyl sheet flooring. The subfloor was one 
layer of thin plywood, one layer of tarpaper, and then one layer of 
particle board. Moisture from the top (cat pee & plumbing leaks) had 
rotted a lot of the particle board and moisture from the bottom 
(plumbing leaks?) had caused a LOT of mold on the under side of the 
plywood and floor joists, though not enough (in most cases) to destroy 
them. (The bathroom was the exception.)  Seeing all the mold on the 
underside of the subfloor and the joists is what is leading me toward 
the moisture barrier....though if all I'm doing is containing the 
moisture inside the barrier, then it won't help, I realize...hence my 
questions.  Our crawl space is NOT big enough to get in there on a 
regular basis to investigate and we're not spring chickens anymore.

I appreciate your feedback!
--Leslie

On 1/14/15, 11:56 AM, Antonioli Dan wrote:
> Leslie,
>
> Your concerns about pooling, or ponding, on top of a moisture barrier 
> are very real and in some instances moisture barriers lead to 
> devastating moisture problems with water damage and mold. Also, there 
> are two types of basic systems in use, and heavily debated, which are: 
> 1) tightly sealed crawlspaces that don’t let cold air in and; 2) 
> vented crawlspaces that can breath and prevent moisture and mold from 
> developing. If keeping your floor warm is the main issue then a vapor 
> barrier may not do much of anything. In general crawlspace moisture 
> barriers don’t do anything for energy efficiency.
>
> Now is the time of year to inspect the dirt for moisture. Is there a 
> lot of moisture? Is there mud? Is there standing water? Or is it dry? 
> If it’s dry I wouldn’t bother with a moisture barrier at all and 
> instead focus on a good floor joist insulation.
>
> Dan Antonioli
> http://going-green.co
>
>
>
> On Jan 13, 2015, at 6:07 PM, Leslie Moyer <unschooler at lrec.org 
> <mailto:unschooler at lrec.org>> wrote:
>
>> Yes, the company does that, too.  Radon is not TOO much of a problem, 
>> generally, in this part of the country, but it was where I lived in 
>> Iowa, so I'm aware.  And I know it CAN be a problem anywhere.  We had 
>> to remediate radon before selling a house in Iowa once.  Thanks!
>>
>> I talked to this company on the phone today re: my second concern and 
>> they have 2 possible solutions he proposed that they use.  One is a 
>> moisture monitor (alarm) and the other is a moisture monitor with a 
>> sump pump.  I still have questions about how this would work (where 
>> would best placement of this/these be?), but feel better knowing it 
>> can be addressed.
>>
>> --Leslie
>>
>> On 1/13/15, 6:47 PM, ErgoDesk wrote:
>>> I would also add RADON protection.
>>>
>>> Sincerely,
>>> George Hawirko_
>>> _
>>> _http://about.me/StyroHome_
>>>
>>> On Tue, Jan 13, 2015 at 12:05 PM, Leslie Moyer <unschooler at lrec.org 
>>> <mailto:unschooler at lrec.org>> wrote:
>>>
>>>     I'm getting ready to have some work done on my
>>>     crawlspace....vapor barrier on the ground & wall insulation. 
>>>     I'm calling a local company whose info I got from this website
>>>     to do an estimate:
>>>     http://www.basementsystems.com/crawl-space/crawl-space-vapor-barrier.html
>>>
>>>     I'll ask these questions when they come to do the estimate, but
>>>     also thought I would ask here (for unbiased answers).  I have
>>>     two questions/concerns.
>>>
>>>     1. We had a small addition added to the end of our long, skinny
>>>     ranch house last winter.  Imagine a long rectangle...we added
>>>     about 15 feet to the east end of it (a bathroom & extended
>>>     bedroom). I had them finish that new part of the house
>>>     crawlspace in the "right" way (with a vapor barrier on the
>>>     ground & wall insulation), but since the rest of the (old) part
>>>     of the house crawl space is insulated in the (house) floor, the
>>>     new floor is cold.  We knew we were doing this work soon-ish,
>>>     and are just now getting around to it.  They knocked a
>>>     people-size hole in the end of the old foundation to allow
>>>     access to the new part of the crawl space, but I'm worried that
>>>     the existing foundation (that runs the width of the house) will
>>>     be a long thermal bridge that never allows the new end of the
>>>     house to warm up. Thoughts?
>>>
>>>     2. Our plumbing runs are in the crawlspace and we had a bad
>>>     plumbing leak there last year.  The kitchen sink drain became
>>>     unhooked from the main drain pipe (or was never hooked up well
>>>     to begin with) and was leaking water and some food waste under
>>>     there for at least a year--probably longer. Not helped by the
>>>     fact that our septic was also backing up, we think.  It all got
>>>     fixed when we did the addition and renovated both bathrooms (and
>>>     did work on our septic lines), but the way we knew it was
>>>     leaking was the smell coming from the crawlspace vents.  And we
>>>     had a great deal of difficulty finding a plumber willing to get
>>>     under there and fix it. Anyway--if we have plumbing problems
>>>     again--even a small leak--with a vapor barrier down there, isn't
>>>     it going to create a swimming pool?  How would we know?
>>>
>>>     I hate crawlspaces.
>>>
>>>     --Leslie Oklahoma
>>>
>>
>> _______________________________________________

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