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Sealing up basement walls with DRYLOC

Post in 'DIY and General non-hearth advice' started by Seasoned Oak, Aug 13, 2012.

  1. Seasoned Oak

    Seasoned Oak Minister of Fire

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    My furnace room basement walls (concrete) weep water after periods of heavy rain. Drives the humidity of my basement up in summer.Have to use a dehumidier all summer. In winter its a help as the inside humidity gets down as low as 25%.
    My question is has anyone had their Basement humidity drop as a result of sealing the walls up with that cement sealing paint? Seems logical.

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  2. seige101

    seige101 Minister of Fire

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    I helped a friend a few years ago seal up his basement with Dryloc. First we sealed up all the cracks about 1foot up with some hydraulic cement then applied 2 heavy coatings to the floor and 2 feet up the walls. Not a drop of water has came in since and the dehumidifier runs about half as often. This spring we painted the rest of the walls all the way to the top and the dehumidifier runs only 2-3 hours a day keeping it a nice 50% RH down there.

    So yes it will make a difference! This was in a cinder block foundation
  3. daveswoodhauler

    daveswoodhauler Minister of Fire

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    I used Drylok in my basement when I finished off a portion of it last year. Part of the permitting process was to have the walls waterproofed, so I used 2 coats of Drylok on all the interior walls. I never had a water issue, but doesn't appear that it had a big impact on the humidity, as the dehumidifier still runs about as much as before.
  4. lukem

    lukem Minister of Fire

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    I have cinder block walls that were painted with waterproofing paint (not sure of exact brand) by the previous owner. I can't tell you what it was like before, but I still have to run the dehumidifier unless I'm running the wood stove.

    I would think you would be able to bring the humidity down some, but I'm not sure that I would assume you won't have to run the dehumidifier at all.
  5. Defiant

    Defiant Vermont Castings Geek

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    I coated the walls in my basement with drylock and then coated them with whatever paint we had leftover from painting the house. I used 4 gallons of the epoxy garage floor paint on the floor. This seemed to help a little (brightened up the basement) but the dehumidifier still runs.:cool:
  6. daveswoodhauler

    daveswoodhauler Minister of Fire

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    If I remember correctly (others may be able to chime in), the Drylok product is not to be used on the floor of the basement..so although the walls might help with the humidity, you would still have the issue of the floor to contend with. Good luck
  7. Danno77

    Danno77 Minister of Fire

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    if your walls are weeping or sweating then that means (one reason) there is moisture in them. What you are proposing is akin to tossing cement into a bucket of water. if you want to solve the real problem you will keep the cement dry, not try to plug the leak.

    imagine what will happen long term if your cement is moisture logged and goes through freeze thaw cycles near the top.

    Also, another reason for damp walls is a temperature differential allowing moisture to condense on the surface (imagine cold glass of lemonade on a humid day). So, instead of moisture directly on the cement you are just gonna get moisture on the surface of the dryloc.
    jeff_t likes this.
  8. Seasoned Oak

    Seasoned Oak Minister of Fire

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    Floor is completely dry,only the back wall which is completely below grade and slopes up on the outside. Its impossible to get at the outside of the wall to waterproof from there as there is a porch and patio there.
  9. Seasoned Oak

    Seasoned Oak Minister of Fire

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    THe water only comes in the bottom 2 feet of the back wall which is completely below grade. It only occurs after heavy rains,so i know it is from the ground water saturating the earth deep. light rains have no effect. Its not from condensation.
  10. lukem

    lukem Minister of Fire

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    If you haven't already, you might want to correct a possible drainage problem before just painting the walls. I'm not familiar with your situation, not trying to offend, but water in basement after heavy rain leads me to believe that you may have a grade issue that's running water toward your house instead of away from it. You may have already been down this road, but I had to mention it. Are your slope away from the house, gutters, and downspout run-off adequate?

    EDIT: should have read more before I posted. It sounds like you've evaluated your drainage situation. You might want to get so pro advice because I don't think a coat of paint is going to do much more than put a band-aid on a large problem. Your basement is your foundation...don't skimp on it.
  11. daveswoodhauler

    daveswoodhauler Minister of Fire

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    Luke made a good point about the drainage issue...sounds like you really don't have access to the back as it covered by the porch patio.
    Does the patio slope towards the backk of the house? (If the patio is brick, and not sloping away from the house this might be a big issue....also, any gutters?

    I think it might be worth the effort to put on the Drylok in this situation. The stuff is pretty thick, so it does take some time to work it onto the walls....lot harder than just rolling out paint.
    You were going to do the entire basement correct? (I am guessing you were, just figured I would ask in that if you only do the back wall, the water that once had penetrated that back wall might then migrate to the left and right walls if it has no where to go)
    Also, are you getting standind water on the floor near the bottom of the wall? or is the wall just damp to the touch?
  12. jharkin

    jharkin Minister of Fire

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    +1

    Sealing the inside wont work.... That water needs to go somewhere and all you are doing is trapping it in the wall accelerating the decay of the structure (or worst case even inviting a blowout someplace if there is no path to relieve the pressure that will build up)

    http://www.buildingscience.com/docu...nvestigating-and-diagnosing-moisture-problems

    http://www.buildingscience.com/docu...er-control/?searchterm=basement waterproofing

    http://www.buildingscience.com/documents/reports/rr-1015-bulk-water-control-methods-for-foundations
    skip to page 8


    I usually cant stand Holmes on Holmes but this is one case where his methods are spot on. If you have chronic water issues you need to excavate and work from the outside of the foundation with sealing and drainage. Thing is that probably costs more than a lifetime of dehumidifier bills.
  13. Seasoned Oak

    Seasoned Oak Minister of Fire

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    The whole yard slopes toward the house. i fixed it to some extent by leveling out about 15 Ft, put in a patio with a drain. I also have a sump pump in th efloor right in the middle of the basement wall right at the bottom of the wall that runs pretty regular after heavy rains.
  14. Seasoned Oak

    Seasoned Oak Minister of Fire

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    No way can i get at the outside.Not going to happen. My line of thinking is if i seal up the wall the water will travel down behind the wall to the french drain i installed around the perimeter of the room , thus relieving the humidity issue somewhat.
  15. daveswoodhauler

    daveswoodhauler Minister of Fire

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    You may be on to a soluton if the side walls don't have the same issue as the rear of your house? (i.e. how is the drainage on either side of the house....are they more sloped away from the foundation?)
  16. Danno77

    Danno77 Minister of Fire

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    i dunno about all of this. I consider it to be akin to the following concept:

    there's water dripping in my bedroom when it rains. I know the water is coming from a leak in the roof, but the roof is too steep and too high to get to, so I'm just gonna use 20 coats of latex paint and hope it reroutes the water down the inside of the wall and to the basement where there are drains.

    It won't end well, unfortunately the failure usually comes MUCH later than the bad repair. This is why houses don't last more than 40 years or so anymore. (i just made that number up)
  17. Seasoned Oak

    Seasoned Oak Minister of Fire

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    The side wall got wet only once or twice in the twenty years im here.(During flooding type rain events)The back wall gets wet after every heavy rain event ,but only about 2 Ft up from the bottom(nothing through the upper 6 Ft) Light to normal rains,the wall stays dry.
    I was also considering lag screwing cement board to the wall with about a quarter inch gap behind it. Therby allowing the water to travel down to the sump but behind the cementboard. Might keep the humidity down a bit.
  18. Seasoned Oak

    Seasoned Oak Minister of Fire

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    Probably cost me 20 Grand to tear out my back porch and also my patio( thick concrete)to get at the outside of that wall. Id rather run the dehumidifier.
  19. webbie

    webbie Seasoned Moderator Staff Member

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    This is only somewhat related, but my rear yard slopes toward a small wall of my basement (has lots of various corners and step outs) - and the water pools under a deck which is in that corner. The builder, with ignorance, put one of those basement windows there under the deck - so when it rains really hard, the water pools up high enough to run in that window and soak the basement floor in my office room!

    I removed the carpet, painted the floor, etc. - but now I have isolated the water intrusion to that window. You cannot get to it from the outside without removing a large part of the deck.

    Last week I got really mad at the thing - and reached through the window and dug a hole with a small hand shovel, installed a bucket with holes and screening, and then put a sump pump in there! I also installed a stainless dam of sorts which should allow the water to come up an inch or two and still not enter the window.

    What I really need to do someday is install a couple dry wells outside the deck and make it so a lot of the water drains into them. We have fairly sandy soil, so that may also help. In the meantime, I'm hoping my first two lines of defense hold...and I may add a third!
  20. Seasoned Oak

    Seasoned Oak Minister of Fire

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    The water that does come through doesnt get far as its all a foot or 2 from the french drain and sump pump.
  21. Danno77

    Danno77 Minister of Fire

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    Oh, I hear ya, I'm just saying that there's a problem (doesn't sound like a big problem, but it's there) and most of the time the correct solution would be better than fixing the damage later. You ever seen what goes into pouring a new basement wall when it fails near the base? it aint pretty. hopefully it will be far enough in the future that it doesn't matter!
  22. Seasoned Oak

    Seasoned Oak Minister of Fire

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    As long as that sump pump does its job you should be OK. Make sure you got one that comes on right away when the water comes in,some of them the water has to be like 6-8 inchs deep before they start up. those electronic ones come on the instant they detect water.
  23. Seasoned Oak

    Seasoned Oak Minister of Fire

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    House is already 100 years old and ill probably sell it in the next 2 years. I sell houses and hold the mortgages. It is fairly minor but an annoyance as the rest of the basement is finished. This area is where the furnace and waterheater is.
  24. daveswoodhauler

    daveswoodhauler Minister of Fire

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    Do you have any excavation contractors in your area that have access to a directional drill? They could perhaps drill a bore on the rear of your house and you could install a drain line.....just thinking out loud....here is an example of what I am referencing:

    http://www.binzandsons.com/Directional Drilling.htm
  25. Seasoned Oak

    Seasoned Oak Minister of Fire

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    Iv already got a drain in my patio which drains into the sewer line. It takes a lot of water during rainstorms. I Actually have a boring drill unit that can go 50Ft.

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