Anhydrite subfloor opinions

Discussion in 'Subfloor Preparation' started by HC&F, Nov 8, 2023.

  1. HC&F

    HC&F Well-Known Member

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    Been to look at a job, (new build) I’m adamant it’s anhydrite. Spoke to site manager he assures me it’s concrete. It does look like anhydrite. It has fibres in it if that helps that I’ve never seen before. Any opinions appreciated
     
  2. Rugmunching

    Rugmunching Well-Known Member

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    Had the same last month with a new build. Site agent telling me it's concrete then seen another agent further up the plots telling me its anhydrite....then the lady in reception its power floated :D

    I knew it was anhydrite anyway.

    Are there some fibre sticking up out the concrete?
     
  3. HC&F

    HC&F Well-Known Member

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    Yea loads of fibres sticking out, never seen as many
     
  4. mjfl

    mjfl Well-Known Member

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    Needs grinding and it can be a pig to do, or should I say the ones I have ground of have been
     
  5. HC&F

    HC&F Well-Known Member

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    Yea, I get that. Have you ever seen anhydrite with fibres in or just concrete?
     
  6. mjfl

    mjfl Well-Known Member

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  7. HC&F

    HC&F Well-Known Member

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    Turns out the subfloor is concrete with GGBS in it, replacing 75% of the concrete. Never heard of it before, every days a school day
     
  8. merit

    merit Well-Known Member

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    What the hell is GGBS
     
  9. HC&F

    HC&F Well-Known Member

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    Ground granulated blast furnace slag :confused:
     
  10. HC&F

    HC&F Well-Known Member

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    It’s a filler apparently that replaces the cement content
     
  11. mjfl

    mjfl Well-Known Member

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    Helps the subfloor from cracking.
     

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