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Community and Q&A

Crawl Space Storage, Zone 5a CT

jenniferz5 | Posted in General Questions on

Five years ago, my non-vented crawl space was insulated and “waterproofed” – top to bottom – from the outside (bitumen layer and Rockwool) and encapsulated on the inside – floor to sill plate) with a layer of thick plastic taped at all seams.  A Santa Fe dehumidifier runs 24/7/365 and we have not had any further issues with water/dampness (nor rodents, as of late).

1.  Can I use the crawlspace – which is about 700 sq ft – for storage? 

2. Can the stored items be food (dry beans in 5 gallon buckets, or canned food, for example)?

3.  I plan to place plywood panels flat on the ground along one wall (to protect the plastic), topped by shelving containing items in Rubbermaid-type bins.  Will the plywood on top of the plastic cause any issues, including trapping moisture?

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  1. user-2310254 | | #1

    Hi Jennifer,

    I will give your post a bump. FWIW, I don't see why you can't use this space for storage. If it's dry, conditioned, and sealed, it should be fine.

    Let's see if anyone else has any thoughts, though.

    1. jenniferz5 | | #4

      Thank you!

  2. Expert Member
    BILL WICHERS | | #2

    Be careful how thick that "thick plastic" is. Minimum for this type of application is typically 10 mil (10 thousands of an inch), but it's usually recommended to use something thicker if you're going to be using it for storage or working on it frequently. 20 mil is better if you'll be walking on the materail fairly often.

    Aside from that, I see no issue using this space for storage. I probably wouldn't use plywood here though (although it isn't going to cause a moisture issue), I'd use extra-wide sleepers, probably 2x8 or 2x10, set horizontally under shelving supports (I'm assuming you'll be using some shelving). If you have a router, you can use a roundover bit to put a nice radius on all the edges of the sleepers that will be on the plastic, which will minimize the chances of puncturing or tearing the plastic. If you want to build a walkway, I'd probably use sleepers with some long runners over the top. This would leave air spaces underneath, and would limit the amount of edges pressing into the plastic which is where you could potentially have problems.


    1. jenniferz5 | | #3


      Great idea! I have existing shelving units (some metal, some plastic), so I will put sleepers over the plastic, then plywood (the metal shelves have sharp feet and I don't have a router - yet), then the shelves. It will only be on one wall, so I am not too worried about it, but better safe than sorry.


  3. Expert Member
    BILL WICHERS | | #5

    The small trim routers that Bosch makes are excellent for simple projects like this. One of those and a 3/8" roundover bit and you'll be good to go.


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