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

patchy sandstone slabs

Discussion in 'In the Garden' started by 23vc, 17 Apr 2015.

  1. 23vc

    23vc

    Joined:
    17 Apr 2015
    Messages:
    2,506
    Thanks Received:
    398
    Location:
    Warwickshire
    Country:
    United Kingdom
    Hi
    any idea whats happened here and if its likely to go away?
    Slabs laid on solid base wettish 1:6 sharp sand / cement On top of existing concrete.
    not sure but hoping it's not similar to what you get when you spot bed and it shows through?
    Any ideas welcome!
    [/img]
     
  2. r896neo

    r896neo

    Joined:
    23 Feb 2007
    Messages:
    4,767
    Thanks Received:
    780
    Location:
    Belfast
    Country:
    United Kingdom
    how long have they been down? the problem with laying over a solid concrete base is hat there is nowhere for water to go but up through the flags leaving efflorsence trails and patchs.

    If they have been down a long time it looks like something was spilt on them.

    a picture from directly above would be useful as that one is not super clear.
     
    • Thanks Thanks x 1
  3. Sponsored Links
  4. 23vc

    23vc

    Joined:
    17 Apr 2015
    Messages:
    2,506
    Thanks Received:
    398
    Location:
    Warwickshire
    Country:
    United Kingdom
    Cheers for the reply, I laid them about 4 weeks ago. Looked fine when they went down as you can see in this pic
    Not sure if anythings got on them. I'll try and get a pic from above of later
    There was a strip which I wet concreted on the day before laying which I reckon might line up with most of the patches, was that a big mistake, reckon it'll eventually dry out?
    Thanks again
     
  5. r896neo

    r896neo

    Joined:
    23 Feb 2007
    Messages:
    4,767
    Thanks Received:
    780
    Location:
    Belfast
    Country:
    United Kingdom
    if they are only down that long it could still be efflouresence coming out of the mortar. this is especially common on a solid concrete base as the moisture has to come up.

    If it still looks funny after 2 months and drier summer weather it may be something else.

    Did you use sbr in your bedding by any chance?
     
  6. Sponsored Links
  7. 23vc

    23vc

    Joined:
    17 Apr 2015
    Messages:
    2,506
    Thanks Received:
    398
    Location:
    Warwickshire
    Country:
    United Kingdom
    Thanks mate. Yes I think and hope you're right. It's changed again now and gone white and strange blotches so that's definitely efflouresence.
    no didn't use sbr, used a bit of normal plasticiser, ?
     
  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

     
Loading...

Share This Page