# Crawl Space Encapsulation



## bigwalleye (May 9, 2012)

I was wondering whether anyone has done this, or has had it done to their home's crawl space?

We have a ranch style home in the Cuyahoga River valley.  We see high humidity levels all summer - we don't have central or forced air (propane boiler, I mean, ahem Harmon P35i ). 

We have a crawl space under half of our house - the half with the bedrooms.  Inside our back bedrooms we sometimes see mold growth on the inside of closet doors.  We think it is our unsealed crawl space that is causing this issue.  Not to mention a somewhat funky/musty smell.

We have about 1200 sq feet of crawl space, and it is mainly just dirt/gravel.  Luckily it is dry - no standing water or water intrusion that I can find.

There are some products on the market called DrySpace and CleanSpace (Basement Systems) which essentially are really thick plastic sheets that are affixed to the walls, as high as the footers, and then run across the crawl space floor, overlapping, from one side to the other.  The sheeting is thick enough that you can walk on it or store materials in there, without threat of tearing it for 25 years.  All outside air vents are also sealed up.  Apparently this is the latest thinking on crawl space treatment - they should not be open to outside air.  Sometimes a large dehumidifier is also added.

The wife wants something done soon.  We've lived here almost three years and the situation has remained.  Not sure if I can get away with just laying some thick plastic sheeting across the crawl space or whether I need one of these fancy products.

Any experiences with these products or others?


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## Flatbedford (May 9, 2012)

I had a company called Neutocrete do our dirt crawlspace. They use a proprietary mixture of concrete, vermiculite, and plastics that is pumped in and spread over the floor and up the foundation walls to the sill plate.
Here's a thread that I posted a few years ago.
https://www.hearth.com/talk/threads...d-now-with-pictures-2-2-10.46321/#post-590841
Two years later it gas held up and it does seem to be less drafty and cleaner. I still have a way to go to tighten up the old place, but this has helped.


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## jimbom (May 9, 2012)

http://www.buildingscience.com/docu...-crawlspaces?topic=resources/more-topics/mold


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## webbie (May 9, 2012)

I looked into it for the wet crawl in our condo near the water and decided to take the easy route - works like a charm.

That is, a special crawlspace dehumidifier - I think a company called Santa Fe makes them (among others).

I put the probe from a digital moisture meter down through a hole in the closet floor and monitor it once in a while.....


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## ironpony (May 10, 2012)

Have a licensed company perform a radon test, if it is high ( probably will be you are in Ohio) install a radon system.
they will seal the crawl space with a 6 mil vapor barrier, then install the fan which will create air movement under the plastic removing radon
along with solving alot of your issues.
we get this feedback from our customers after the radon system is installed.
Licensed radon contractor RC94 in Ohio
will kill 2 birds with one stone and a radon system will cost you less than a basement guy coming in to seal it up


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## Crane Stoves (May 10, 2012)

Flatbedford said:


> I had a company called Neutocrete do our dirt crawlspace. They use a proprietary mixture of concrete, vermiculite, and plastics that is pumped in and spread over the floor and up the foundation walls to the sill plate.
> Here's a thread that I posted a few years ago.
> https://www.hearth.com/talk/threads...d-now-with-pictures-2-2-10.46321/#post-590841
> Two years later it gas held up and it does seem to be less drafty and cleaner. I still have a way to go to tighten up the old place, but this has helped.


 
wow, that looks like amazing stuff (i assume it acts like concrete and you can crawl in their and work if needed without damage to this stuff?), This seems to be not only a vapor barrier but also an insulating barrier (which is why they were able to take down all the insulation in the joists?). the cheap way out is to lay down durable plastic and put rocks ontop of that and maintain some degree of airflow thru the crawl space (vents on opposing ends or w/e), but this Neutocrete looks amazing and if money was not an object id surly look into that stuff.

Is the mold in the bedroom closets down low in the closet or up high in the closet? if mostly down low look toward to crawl, if up higher look toward your roof. GL on this sir!


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## granpajohn (May 10, 2012)

I used the 6 mil plastic on our old house which was also half basement, half crawl. Worked very nicely for cheap. I had always had a sump pit in there also, so that is something else to consider. I came home one day and my glasses fogged when I walked into the house. Immediately checked the crawl space, and yes... the sump pump had failed. Proof that it works.
Human nature notice: I had procrastinated for years on the whole thing because I wanted to rake all the gravel, then place the plastic, then rake back the gravel. Too big a job. Finally, I just placed the plastic over the existing gravel mostly, with a few spots of gravel on top. Just to see if it would help. Worked great. Wish I had done it sooner. New owner still has it that way. 
P.S. I did not do anything on the walls...just the dirt/gravel floor


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## Highbeam (May 15, 2012)

You don't need or want to put rocks on top of the 6 mil VB to hold it down, it won't blow away. Just put it down. The plastic is cheap, easy, clean, and is likely all you will ever need. I can't believe your home doesn't have at least the minimum plastic VB on the crawl floor.


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## bigwalleye (May 16, 2012)

Thanks for the replies and suggestions.  Currently there is some plastic sheeting in there that appears to be completely covered with stone/dirt in some places, and exposed in others, semi-torn, etc.  I suppose I could add new plastic sheeting and see if we get any improvement.  The crawl space is tall enough to move around fairly easily either crouched-over or worst case, on my knees.  I don't find the space to be especially humid, but I've never put a hygrometer or anything in there to see.  It's not moldy in there, either, as far as I can tell. 

As for the mold growth in bedroom closets, it's typically on the inside of sliding closet doors, on the low side of the doors. 

How do I increase the airflow inside of closets besides leaving the doors open all the time?  Where would I put cold air returns?  I've got two bedrooms whose closets are back to back, I guess I could put a cold air return (vent) between those two closets increasing air flow in the two rooms?  Otherwise, there's just unfinished crawl space below, and unfinished attic above.

I've heard our neighbors also complain of mold growth in especially humid summers, but I'm not sure of their crawl space situation. 

I guess I'm worried that I'll shell out some fairly big bucks (~$4000) to encapsulate this space and then I'll still have mold growth/mustiness in back bedrooms.  This back bedroom - the worst bedroom - is the master bedroom.  Since its just the wife and me, we use a different bedroom (closer to the living area) but eventually we'd like to remodel the MBR bath room and adjacent walk in closet and use the MBR.  The walk in closet in the MBR gets the least amount of air flow and is probably the worst as far as musty smell goes.  We don't store anything in there.

Ironpony:  I'll check into the radon remediation approach.


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## granpajohn (May 17, 2012)

I think the closet mold may require a separate thread.

I rarely close the door to a closet now. My wife does not quite approve of this.
I am also in the habit of washing closets with bleach in solution. We now keep a bottle of bleach and water mixed up all the time so there will be no delay in treating mildew spots. It usually works after 2 washings.

I'll be interested in the replies/solutions to that issue

I can't believe the humidity in Ohio can be even half that of ours here in the swamps of Anne Arundel.


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## woodsmaster (May 21, 2012)

6 mil plastic works good. Lay it over the floor and run it up the foundation walls to the sill plate. Insulate the rim joist.
You may want a foam cotractor to insulate the rim joist. Tape any seams in the plastic with house wrap tape. sael any vents or cracks going outside. You now have a conditioned crawl space.


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## Don2222 (May 21, 2012)

Hello

Here is a video on a home where a green company comes in and encapsulates the crawl space with very heavy duty yellow plastic among other things.
http://curiosity.discovery.com/question/corn-stoves-pellet-stoves-compare


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