Leveling bad patched and uneven garage floor?

Discussion in 'Garages, Workshops & Tools' started by 8pack, Aug 22, 2016.

  1. 8pack

    8pack Veteran Member Lifetime Gold Member

    Aug 29, 2007
    Pittsburgh, PA
    Leveling badly patched and uneven garage floor?

    I just bought a house in PA. I have a 2 car garage. It has a few problems:

    I don't have pics as I haven't moved in yet, but the garage floor is very uneven. It has cracked or been patched or broken up many time over the years. I am guessing 30-50 years old.

    It is VERY humid in the garage. Although we are not in a particularly wet area there is a lot of moisture coming up through the concrete.

    I had a concrete guy come to see about leveling it and based on the age and condition of the building and floor he didn't think it was worth repairing. It is about 500 sq/ft and he quoted $4k to grind it, patch it and level it. Too expensive for a basic detached 2 car garage.

    I have come up with my own solution and wanted to get thoughts. A couple of years ago I put in a bluestone patio so that is the experience I am drawing from....

    1. First put a 6mil Vapor barrier down to manage the humidity/moisture coming up through the concrete.
    2. Around the perimeter build a wood 2x4 or 2x6 frame
    3. Next use stone dust across the entire floor as a way to level it. Tamp it down well.
    4. Build wood 4x8 frames with interior "joists" using 2x4s throughout the garage.
    5. Screw down marine grade 4x8 3/4 or 1" ply wood to create a new floor.
    6. Put a garage floor mat down like the G-floor mat over the ply wood. https://www.bltllc.com/products/g-floor-vinyl-flooring/solid-color/
    7. I have a quick lift so I would cut out squares in the ply wood to drop cement tiles down through for the quick lift to sit on and be supported by the stone dust and concrete below....

    Hopefully this description makes sense. I think I could do the whole thing for $2,500....maybe not worth the trouble to save $1,500 or maybe the quote was too high. Ideas and thoughts welcome!
    Last edited: Aug 22, 2016
  2. frankz

    frankz Veteran Member

    Aug 24, 2009
    Just me, but before I spent 4 G's to patch I would put down a vapor barrier and pour a new 3" slab over the old.
  3. 1981gMachine

    1981gMachine Veteran Member Lifetime Gold Member

    Dec 28, 2005
    Airville, PA
    Sounds like my garage. Always seems to have humidity in it. The floor is uneven, as in each bay has a "bow." I haven't figured out a way to fix it. I can't afford to loose ceiling height. My current idea is to pressure wash, clean/etch the floor. Use some self leveling concrete and fill the coarseness of the floor. Not make it flat, but the extreme rough texture it has. Then epoxy paint it. I'm going to have a full time de humidifier out there so I'm hoping that will help.
  4. grzewnicki

    grzewnicki Veteran Member Lifetime Gold Member

    I deliver concrete and see how the pros repair uneven slabs. Basically the scarify (groove) the existing concrete, put a bonding agent down, then pour the right concrete mix down (I've seen as little as 2 inches poured in commercial settings to repair a bad slab). You maybe able to rent the machine to groove the concrete but this may be something only a pro has, I'd call your local concrete company and ask to talk to a salesman and tell him what you need to accomplish. Not entirely sure of what to do for the moisture problem your having though. Another possiblity would be to lay poly down (plastic sheeting) then pour a 3 to 3.5 inch slab of something like a 3500 PSI peastone mix with 1.5 pounds of fiber reinforcement in it. I'd have a hard trowel finish done, it comes out glossy and is pretty impervious to soaking up spills. You might want to check with a couple of other concrete guys, I think these two options are best bet of getting a long lasting solution and I'd spend the extra money to get it done with concrete vs wood. Other note when you call a local concrete company ask the salesman for the names of some good concrete finishers. I know I have two guys I have worked with over the years and I always recommend them cause I know they do quality work.
    Last edited: Aug 23, 2016
  5. 351maverick

    351maverick Veteran Member

    Aug 11, 2010
    erie, PA
    around here concrete is $4/sq foot installed

    I would break up the floor (rent a jackhammer if you have to) then pay the $2000 for a new slab - it will be a very easy pour since it's already framed on 3 sides

  6. 70lt1z28

    70lt1z28 Veteran Member Gold Member

    Oct 3, 1999
    Beavercreek, Ohio, USA
    Many older houses in this area have broken garage slabs. Usually you will see the crack go from garage door corner to corner. When they built these houses in the 50-60-70's building code did not need footers under the garage door openings. Dumb. When a 2 ton car rolls in guess what gives?

    My advice would be to jackhammer, check for a footer at the opening and put one in if its not there and pour a slab. I know it's expensive, but do the work yourself (besides the pour and the finish work) and it will be best in the long run.

    I am pretty sure around here the county building Nazis wouldn't even consider a wood floor. They would probably condemn my house if they found out.
  7. budro6968

    budro6968 Veteran Member

    Apr 2, 2016
    Jax Florida
    I had my 10'x10' slab done and a metal building put up for 5600.00. I think the concrete guy was to high. I would find someone else. Maybe jack hammer it out first then have it poured a good 4" monolithic slab with rebar in the footing and mesh in the center over a good vapor barrier.
  8. 8pack

    8pack Veteran Member Lifetime Gold Member

    Aug 29, 2007
    Pittsburgh, PA
    It sounds like I need to go back in for some more estimates. I can't personally jackhammer the floor. Not in the right decade for that! Plus a few prior surgeries makes it ill advised.

    I will keep looking at options. My solution does not sound like the best approach.
  9. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

    Feb 26, 2004
    Bloomington, MN
    Your solution may work, but I'm afraid the floor will continue to shift over the years.

    Mud-jacking the low parts back into place can work wonders and be a relatively permanent solution. (If it's like one or two corner or near the apron.)

    If it's busting up badly or the surface is getting crumbly... Remove and replace.
  10. 8pack

    8pack Veteran Member Lifetime Gold Member

    Aug 29, 2007
    Pittsburgh, PA
    Its broken up in enough places and there are many patch attempts that don't make it worth it to try and repair. Something has to go over it or break it up and replace it......Next week I will have some pics.

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