1. Subfloor: The structural layer beneath the flooring surface.
  2. Underlayment: A layer of material placed between the subfloor and the flooring material for various purposes such as moisture protection, sound insulation, or cushioning.
  3. Flooring material: The actual material used for covering the floor, such as hardwood, laminate, vinyl, tile, carpet, etc.
  4. Adhesive: A substance used to bond the flooring material to the subfloor.
  5. Expansion gap: A space left around the perimeter of a room to allow for the natural expansion and contraction of the flooring material.
  6. Trowel: A tool with a flat, pointed blade used for spreading adhesive evenly.
  7. Planks/tiles: Individual pieces of flooring material, usually referring to hardwood, laminate, or tile flooring.
  8. Grout: A material used to fill the gaps between tiles.
  9. Joint: The point where two pieces of flooring material meet.
  10. Transition strip: A molding used to cover the gap between different types of flooring materials or between rooms.
  11. Baseboard/molding: Trim used to cover the joint between the wall and the flooring material.
  12. Undercut saw: A specialized saw used to cut door jambs and trim to allow flooring to slide underneath.
  13. Moisture barrier: A material or coating used to prevent moisture from seeping through the subfloor and damaging the flooring material.
  14. Floating floor: A type of flooring installation where the individual planks or tiles are not attached to the subfloor but instead interlock with each other.
  15. Seam sealer: A product used to seal the joints between vinyl flooring tiles or sheets.
  16. Expansion joint: A deliberate break in the flooring material used to accommodate expansion and contraction due to temperature and humidity changes.
  17. Floor scraper: A tool used to remove old flooring material or adhesive from the subfloor.
  18. Leveling compound/Float: A material applied to the subfloor to create a smooth and level surface for the flooring installation.
  19. Knee pads: Protective gear worn by installers to cushion their knees during floor installation.
  20. Spacers: Small wedges or blocks used to maintain consistent spacing between flooring planks or tiles during installation.

These are just some of the common terms you might encounter in discussions about flooring installations.