Crawl Space Suggestions

Discussion in 'General Home Improvement Discussion' started by drewdin, Sep 24, 2012.

  1. Sep 24, 2012 #1

    drewdin

    drewdin

    drewdin

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    Hi All,

    I have a crawl space that is roughly 10' x 10' square. Its got a dirt floor and is only about 3.5' tall without any ventilation. The walls are cinder-blocks and it gets real humid in there, I wanted to cement the floor but I wasn't sure if that was correct.

    I have read that I should put 6mil of plastic down and then some gravel over it, Ill post some pics of it tomorrow but I was wondering if it was better practice to just put a 2-3" layer of cement and call it a day.

    Any help would be greatly appreciated.
     
  2. Sep 24, 2012 #2

    nealtw

    nealtw

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    We do the poly, 3" concrete and ventulation.
     
  3. Sep 24, 2012 #3

    drewdin

    drewdin

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    Hi nealtw,

    I didn't think I could add ventilation as its under the extended part of my kitchen. It was a porch that the previous owner closed in and the only way to get in is the window from my basement. There is electrical and heating pipes there and that's it.

    SO i should put poly onto the dirt floor, seal it to the concrete and then put 3" of concrete on top? Is that correct? What do I use to seal the vapor barrier to the concrete, liquid nails?

    I'll have some pics of the entry and space on here later. Thanks
     
  4. Sep 24, 2012 #4

    woodchuck

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    Put the polly down and leave it at that. Moisture will stay in the ground under the polly.
     
  5. Sep 24, 2012 #5

    jmc0319

    jmc0319

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    I just did the same to my crawl space. Put down the poly, it goes up 6" on the block foundation and is glued. Then we sprayed 2" of closed cell foam on the block. It has made a huge difference already.
     
  6. Sep 24, 2012 #6

    drewdin

    drewdin

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    ALl i can find for closed cell foam is window weatherstripping at lowes/HD. What did you use for glue? Thanks again for the suggestions
     
  7. Sep 24, 2012 #7

    jmc0319

    jmc0319

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    Let me be clear, I did nothing for this job except pay the pros with a check.
     
  8. Sep 24, 2012 #8

    Wuzzat?

    Wuzzat?

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    Black mold is worse than white mold.:eek:
     
  9. Sep 25, 2012 #9

    nealtw

    nealtw

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    Our code calls for concrete but that is kinda new. What we is level the dirt os usually sand and glue 3 1/2 sill gasket to the foundation with acoustic sealer and poly on the sand and pore concrete. I'm sure you could get away with out concrete but if you insulate tha concrete walls and don't have venting, you are making this room part of the basement and should remove the window and leave the hole open.
    If you are leaving it as part of the basement I would want concrete but getting it in there should be a job and a half.
     
  10. Sep 25, 2012 #10

    drewdin

    drewdin

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    Thanks for the suggestions, here are some pics of the crawl space. It is located under my kitchen, the floor is the same grade as the outside dirt. I plan on pouring 3" of concrete over a 6mil tarp that will be sealed to the concrete surrounding. Then I will use something similar to Extruded Polystyrene Insulated Sheathing on the walls but I just want to make sure that is the bets way to do it.

    The top picture is the entry to the crawl space, the next three are the left, center and right walls looking through the old window. I have already removed the older insulation and drywall that was placed on the dirt floor, it was so wet it was literally dripping water.

    2012-09-24 19.26.50.jpg

    2012-09-24 19.27.09.jpg

    2012-09-24 19.27.14.jpg

    2012-09-24 19.27.27.jpg
     
    Last edited: Sep 25, 2012
  11. Sep 25, 2012 #11

    nealtw

    nealtw

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    On the outside you should have a perimiter drain at the footing level or at least below the the dirt level inside. There should be 6" to 8" of concrete or wall above the dirt outside and the landscape should slope away from the house. Insulating the floor with fiberglass would have worked if the space was vented from the outside but the solid surface should not have been there.
    Doing anything on the inside before fixing the outside may not be productive.
     
  12. Sep 25, 2012 #12

    drewdin

    drewdin

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    I have to do some work outside to slope the landscape and move the downspout farther away from the house. Thanks for the info
     
  13. Sep 27, 2012 #13

    nealtw

    nealtw

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    I would do that first and maybe alot of moisture would not be in the crawl space. The insulation above the foam will be a problem and should be replaced and held in place with some more like chicken wire fencing so you have air movement below and then I would just knock out a couple concrete blocks and poly the floor.
     
  14. Sep 27, 2012 #14

    Wuzzat?

    Wuzzat?

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    Depending on how much your labor is worth, you may want to price out a humidistat and a fan. Two Air Changes per Hour is one benchmark figure for pulling in outside air.
     
  15. Sep 28, 2012 #15

    drewdin

    drewdin

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    Is there a proper way to slope the landscape or do I just slope the landscape? Yesterday I fix4ed the gutters and sloped the landscape a little but I wasn't sure how high and the grading it should be. Its been raining all morning here, I'm going to check it when i get home.
     
  16. Sep 28, 2012 #16

    nealtw

    nealtw

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    Making sure the water gets away from the house is all you really need. After a good rain dig a few holes next to foundation, dirt should be dry. It is important to have 6 to 8 inches of wall showing on the outside. The wall will wick water up and it needs to air dry at the top. If you can not get the dirt to stay dry you will have to think about perimiter drain on the outside.
     
  17. Sep 28, 2012 #17

    drewdin

    drewdin

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    There is about 2 feet or so of brick showing on the outside, ill post a pic later today. How big of a job is it to install a perimeter drain?
     
  18. Sep 28, 2012 #18

    nealtw

    nealtw

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    You would like to put the drain at the level of the footing or at least well below the level of the dirt inside. Perferated pipe around the outside and run down hill to city storm or daylite or sump pump it out. So it would be a little digging a little hauling gravel to cover the pipe, filter cloth to cover that and backfill. If you do go to all that you may as well waterproof the wall with a tar like product up to landscape level.
    Sounds easy if you say it fast.:cool:
     

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