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

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.


INTRODUCTION

IMPACT ISOLATION


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.


INTRODUCTION

IMPACT ISOLATION


IIC IMPROVEMENTS

IMPACT NOISES


INTRODUCTION

IMPACT ISOLATION


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.


INTRODUCTION

IMPACT ISOLATION CUSHIONED FLOORS

FLOATED FLOORS

SUSPENDED CEILINGS

ISOLATE VIBRATING ELEMENTS


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.


INTRODUCTION


FLOATED FLOORS

SUSPENDED CEILINGS



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.


INTRODUCTION


FLOATED FLOORS

SUSPENDED CEILINGS



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.


INTRODUCTION


FLOATED FLOORS

SUSPENDED CEILINGS



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.


INTRODUCTION


FLOATED FLOORS

SUSPENDED CEILINGS



IIC IMPROVEMENTS

FLOATED FLOORS


INTRODUCTION


FLOATED FLOORS

SUSPENDED CEILINGS



IIC IMPROVEMENTS

CONCRETE FLOATED FLOORS


INTRODUCTION


FLOATED FLOORS

SUSPENDED CEILINGS



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.


INTRODUCTION


FLOATED FLOORS

SUSPENDED CEILINGS



IIC IMPROVEMENTS

SUSPENDED CEILINGS


INTRODUCTION


FLOATED FLOORS

SUSPENDED CEILINGS



IIC IMPROVEMENTS


ISOLATE ALL PIPING:

ALL RIGID, VIBRATING ELEMENTS, SUCH AS PIPING MUST BE ISOLATED AND CAULKED WITH RESILIENT SEALING TO PREVENT STRUCTURE-BORNE SOUND TRANSMISSION.


INTRODUCTION

IMPACT ISOLATION


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.


INTRODUCTION

IMPACT ISOLATION


IIC IMPROVEMENTS


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.


INTRODUCTION

IMPACT ISOLATION


IIC IMPROVEMENTS


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.


INTRODUCTION

IMPACT ISOLATION


IIC IMPROVEMENTS


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.


INTRODUCTION

IMPACT ISOLATION


IIC IMPROVEMENTS


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.


INTRODUCTION

IMPACT ISOLATION


IIC IMPROVEMENTS



INTRODUCTION

IMPACT ISOLATION


IIC IMPROVEMENTS

FHA NOISE CRITERIA


INTRODUCTION

IMPACT ISOLATION


IIC IMPROVEMENTS

IMPACT ISOLATION EFFECTIVENESS

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

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