1. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT NOISES DESCRIPTION:  IMPACT NOISES ARE ERRATIC AND CAN BE CAUSED BY WALKING (HARD HEEL FOOTFALL), ROLLING CARTS, DROPPED OBJECTS, SHUFFLED FURNITURE, SLAMMED DOORS AND THE LIKE.

2. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT NOISES DESCRIPTION:  IMPACTS ON FLOORS ARE RADIATED DIRECTLY DOWNWARD.  THEY ALSO CAN BE TRANSMITTED HORIZONTALLY THROUGH THE STRUCTURE AND BE RERADIATED AT DISTANT LOCATIONS.  IT IS BEST TO PREVENT IMPACT SOUND ENERGY FROM ENTERING THE BUILDING STRUCTURE.

3. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT NOISES

4. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT NOISES

5. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT NOISES AT LEAST AS SERIOUS A PROBLEM AS AIRBORNE NOISE BECAUSE:  HIGH INTENSITY ENERGY IS INTRODUCED DIRECTLY INTO THE STRUCTURE.  SINCE THE STRUCTURE MUST HAVE INTEGRITY TO CARRY LOADS, DISCONTINUITIES (WHICH ATTENUATE SOUND) ARE COMPLEX & EXPENSIVE.  STRUCTURE CONSTITUTES A NETWORK OF SOUND PATHS.

6. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION  CUSHIONED FLOORS  FLOATED FLOORS  SUSPENDED CEILINGS  ISOLATE VIBRATING ELEMENTS IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS CUSHIONED FLOORS CUSHIONED FLOORS:  STRUCTURE-BORNE SOUND CAN BE ISOLATED BY CUSHIONING THE IMPACT.  CARPETING AND RESILIENT RUBBER FLOOR TILES CAN BE USED TO CUSHION THE IMPACT.

7. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION  CUSHIONED FLOORS  FLOATED FLOORS  SUSPENDED CEILINGS  ISOLATE VIBRATING ELEMENTS IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS CUSHIONED FLOORS CUSHIONED FLOORS:  THEY ARE MOST EFFECTIVE AS ISOLATORS OF MID- AND HIGH-FREQUENCY IMPACT NOISES SUCH AS “CLICKS” FROM FOOTSTEPS.  LOW-FREQUENCY “THUDS” FROM THINGS BEING DROPPED STILL MAY BE TRANSMITTED THROUGH CONSTRUCTIONS HAVING CARPETING AND RESILIENT RUBBER FLOOR TILES.

8. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION  CUSHIONED FLOORS  FLOATED FLOORS  SUSPENDED CEILINGS  ISOLATE VIBRATING ELEMENTS IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS FLOATED FLOORS DESCRIPTION:  FLOATED FLOORS ARE SLABS (OR FLOOR ASSEMBLIES) WHICH ARE COMPLETELY SEPARATED FROM THE STRUCTURAL SLAB BY A RESILIENT UNDERLAYMENT OR BY RESILIENT ISOLATORS.

9. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION  CUSHIONED FLOORS  FLOATED FLOORS  SUSPENDED CEILINGS  ISOLATE VIBRATING ELEMENTS IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS FLOATED FLOORS PARTITIONS:  PARTITIONS BORDERING FLOATED FLOORS SHOULD NOT SET ON THE FLOATED FLOOR.  THIS RESULTS IN EITHER AN OVER COMPRESSED RESILIENT ISOLATOR OR A SHEAR FAILURE IN THE FLOATED SURFACE.

10. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION  CUSHIONED FLOORS  FLOATED FLOORS  SUSPENDED CEILINGS  ISOLATE VIBRATING ELEMENTS IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS FLOATED FLOORS

11. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION  CUSHIONED FLOORS  FLOATED FLOORS  SUSPENDED CEILINGS  ISOLATE VIBRATING ELEMENTS IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS CONCRETE FLOATED FLOORS

12. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION  CUSHIONED FLOORS  FLOATED FLOORS  SUSPENDED CEILINGS  ISOLATE VIBRATING ELEMENTS IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS SUSPENDED CEILINGS SUSPENDED CEILINGS:  THE CEILING IS SUSPENDED FROM ISOLATION HANGERS WITH A 6” OR MORE AIR SPACE.  OFTEN FIBROUS INSULATION IS PLACED IN THE PLENUM.

13. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION  CUSHIONED FLOORS  FLOATED FLOORS  SUSPENDED CEILINGS  ISOLATE VIBRATING ELEMENTS IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS SUSPENDED CEILINGS

14. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION  CUSHIONED FLOORS  FLOATED FLOORS  SUSPENDED CEILINGS  ISOLATE VIBRATING ELEMENTS IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS ISOLATE VIBRATING ELEMENTS ISOLATE ALL PIPING:  ALL RIGID, VIBRATING ELEMENTS, SUCH AS PIPING MUST BE ISOLATED AND CAULKED WITH RESILIENT SEALING TO PREVENT STRUCTURE- BORNE SOUND TRANSMISSION.

15. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT ISOLATION CLASS IMPACT ISOLATION CLASS:  A SINGLE-NUMBER RATING OF THE IMPACT SOUND PERFORMANCE OF A FLOOR- CEILING CONSTRUCTION TESTED OVER A STANDARD FREQUENCY RANGE.  THE HIGHER THE IMPACT ISOLATION CLASS, THE MORE EFFICIENT THE CONSTRUCTION WILL BE IN REDUCING IMPACT SOUND TRANSMISSION.

16. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT ISOLATION CLASS IMPACT ISOLATION CLASS:  THE IIC RATINGS VARY FROM 25 FOR A BARE CONCRETE SLAB TO 57 FOR FLOATED FLOOR CONSTRUCTION.  TO ACHIEVE HIGH IIC’S USE SOFT FLOOR SURFACES, CEILINGS SUSPENDED UNDER SLABS, FLOATED FLOORS, OR ALL THREE OF THESE IMPACT CONTROL MEASURES.  AVOID HARD SURFACES SUCH AS BARE CONCRETE, TERRAZZO, VINYL TILES AND LINOLEUM.

17. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT ISOLATION CLASS IMPACT ISOLATION CLASS:  IN THE UNITED STATES, THE IIC RATING METHOD IS RECOMMENDED BY THE FEDERAL HOUSING ADMINISTRATION (FHA) AS A RATING OF IMPACT SOUND ISOLATION EFFECTIVENESS.  THE IIC METHOD IS BASED ON MEASUREMENTS OF THE SOUND PRESSURE LEVELS PRODUCED IN A ROOM DIRECTLY BELOW THE TEST FLOOR ON WHICH A STANDARD TAPPING MACHINE IS OPERATING.

18. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT ISOLATION CLASS IMPACT ISOLATION CLASS:  IIC TESTS ARE MEASURED AT 16 FREQUENCY BANDS CENTERED FROM 100 HZ TO 3150 HZ.  A HIGH IIC NUMBER DOES NOT NECESSARILY MEAN THAT IMPACT ISOLATION WILL BE SATISFACTORY BECAUSE THE IIC METHOD DOES NOT CONSIDER IMPACT SOUND TRANSMISSION BELOW 100 HZ.

19. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT ISOLATION CLASS IMPACT ISOLATION CLASS:  IMPACT NOISE PROBLEMS CAN ARISE AT LOW FREQUENCIES, COMMONLY OCCURRING WITH LIGHTWEIGHT STEEL OR WOOD FRAME FLOORING SYSTEMS.  WHERE IMPACT ISOLATION IS REQUIRED, AVOID ESPECIALLY LONG UNSUPPORTED FLOOR SPANS AND EXCESSIVE FLOOR DEFLECTION.

20. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT ISOLATION CLASS

21. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS FHA NOISE CRITERIA

22. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT ISOLATION EFFECTIVENESS

23. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT ISOLATION EFFECTIVENESS

24. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT ISOLATION EFFECTIVENESS

25. STRUCTURE-BORNE SOUND INTRODUCTION IMPACT ISOLATION IMPACT ISOLATION CLASS (IIC) IIC IMPROVEMENTS IMPACT ISOLATION EFFECTIVENESS