The following are some good construction practices to follow when building your floating slab:

  1. Floating slab are to rest on undisturbed soil.  Remove all organic material from beneath building. 
  2. Ensure the subgrade is uniform and sufficiently compacted.
  3. Provide good site drainage by sloping all surface grades and the subgrade.  Surface grades should be a minimum 5% grade (3inches in 5 feet)
  4. Dampen subgrade before placing the concrete.
  5. Never pour concrete on frozen subgrade.
  6. Minimized concrete shrinkage by using a low slump (stiff mix). 
  7. Don’t add water on site during placement or finishing.
  8. Use chairs to support the slab reinforcement mesh at the correct height during concrete pouring.
  9. The thickened slab area rebars in the slab corners should be continuous.
  10. Don’t  over-trowel to help prevent cracks.
  11. There should be a sill anchor bolt 1’-0” from each corner of the slab.  The rest of the sill anchor bolts should be imbedded into the concrete as per the stamped drawings or municipal handout drawing. 
  12. Keep concrete moist for 24 hours
  13. Protect concrete from wind & direct sun
  14. Keep concrete temperature above 10 degrees during and for 3 days after placement.

Engineering for floating slabs is provided by Waddell Engineering.


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