1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Levelling garage floor

Discussion in 'Building' started by phil81uk, 8 Aug 2010.

  1. phil81uk

    phil81uk

    Joined:
    8 Aug 2010
    Messages:
    10
    Thanks Received:
    0
    Location:
    London
    Country:
    United Kingdom
    My garage floor is very rough, with stones and all sorts in it. On one side of the garage, where a wall was modified, the conctrete has been raised by 35mm for some reason.

    I was about to do formworks and rasie the floor with conrete by 50mm (would be 15mm where the concrete is already higher). I was going to do it in four sections to make the job more manageable.

    But from what I've now read on forums, putting a layer of concrete on top of an existing layer is not recommended because it doesn't stick to the layer below and because it expands at a different rate. But none of the texts I read stated how thick the new layer would need to be so that it doesn't crack.

    Will I have to remove the old slab?
     
  2. Sponsored Links
  3. PrenticeBoyofDerry

    PrenticeBoyofDerry

    Joined:
    30 Jun 2009
    Messages:
    21,628
    Thanks Received:
    2,383
    Location:
    Londonderry
    Country:
    United Kingdom
    Will garage be used to park your car or is it just storage/workshop?
    If car is to be parked 50mm may be a little small, but the idea is to;
    Repair any major cracks, clean the surface, if it's dust and loose a power cleaner maybe based way and sweep it clean, score the original surface with and angle grinder again removing any dust or dirt afterwards.
    Then apply a bonding adhesive (following instruction on the product, as some are different)
    Then do you pour, I would try to do it in one, if possible.
    Also I would consider a gentle fall/slope out of the garage to prevent water coming in to it, this will be dependant on it's position on your property.
     
  4. phil81uk

    phil81uk

    Joined:
    8 Aug 2010
    Messages:
    10
    Thanks Received:
    0
    Location:
    London
    Country:
    United Kingdom
    It will have a car, and I plan to use it as my workshop when working on the the car, so this mean trolley jacks etc. So what's the recommended thickness?
     
  5. r896neo

    r896neo

    Joined:
    23 Feb 2007
    Messages:
    4,767
    Thanks Received:
    779
    Location:
    Belfast
    Country:
    United Kingdom
    I did this recently for my father and I poured 75mm which was the thinnest i though i could get away with.

    The big thing you have to watch out for it you haven't done much concreting before is how quickly it will dry out. The concrete underneath is bone dry for many years and so if you covered the whole lot in water the water will have soaked in by probably 15mins later.

    To combat this i mixed up 3:1 water - SBR and primed the floor with this literally just as the truck arrived. Alternatively you could spread a thin sheet of polyethene over the floor not so much to stop damp as the old floor will have a dpm but just to give you more time.

    Nothing worse than having your 60 year old father offer to help but then have to stop cause his back is sore after 10 mins leaving you on your own to screed tamp and trowel a 10x4 floor of rapidly hardedning concrete. :evil:

    The best hardest finish will be acheived with a powerfloat or just floating by hand will give you a pretty good result. If you have never really used a float much you might consider getting a plasterer to come and give it a going over for you.
     
  6. phil81uk

    phil81uk

    Joined:
    8 Aug 2010
    Messages:
    10
    Thanks Received:
    0
    Location:
    London
    Country:
    United Kingdom
    I will break up the area that is 35mm higher, and I will put in a 75mm layer.
     
  7. Nige F

    Nige F

    Joined:
    28 Jun 2005
    Messages:
    21,082
    Thanks Received:
    1,721
    Country:
    United Kingdom
    Might be worth looking @ Granolithic screed - or any ready mixed screed :idea: apparently you can get it like readymix concrete now.
     
  8. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
  9. Sponsored Links
Loading...

Share This Page