Noise Control Systems Supplement Issue Date September 2017 GIB Noise Control design notes SUPPLEMENT ISSUE DATE Polyester Sound Control Infill Sept 2017 Enviromental Noise March 2006 SEPTEMBER 2017 GIB HELPLINE 0800 100 442 OR GIB.CO.NZ FOR MORE INFORMATION GIB NOISE CONTROL SYSTEMS SUPPLEMENT 1
Polyester Sound Control Infill Issue Date September 2017 It is acceptable to replace the specified Pink Batts glass wool infill in GIB Noise Control Systems with polyester fibre infill of the same or greater thickness (if not compressed) provided the polyester manufacturer can prove it meets the minimum properties shown in the table below. Product Material Measured Density Kg/m 3 Air Flow Resistivity rayls/m Polyester Infill 100% Polyester 14.7 1900 Based on testing carried out by Winstone Wallboards in April 2017, subject to the conditions below, the noise attenuation ratings specified in GIB Noise Control Systems, 2017 will be retained when polyester fibre infill with the minimum properties listed in the table above are substituted for either R1.2 (50mm), R1.8 (75mm) or R2.2 (90mm) Pink Batts glass wool insulation of the same or greater thickness (refer to the thickness of the Pink Batts specified in the applicable GIB Noise Control System). In most cases GIB Noise Control Systems also provide Fire Resistance Ratings (FRRs). Subject to the conditions below, substituting 100% polyester fibre infill with the minimum properties listed in the table above for either R1.2 (50mm), R1.8 (75mm) or R2.2 (90mm) Pink Batts glass wool of the same or greater thickness will retain the published FRRs for these systems. To maintain the specified STC and IIC ratings, it is allowable to use the same thickness of polyester fibre infill as the originally specified Pink Batts glass wool infill. A greater thickness of polyester fibre infill may be used, provided it is not compressed when installed into the framing cavity. The performance of any other infill product type must be independently verified. Conditions Except to the extent expressly stated in this Testing Statement, where any substitution of cavity infill takes place, independent verification must be obtained to confirm that the noise control performance of the system will be maintained. Polyester fibre infill, and other insulation products, properties and characteristics may vary by product type and manufacturer. It remains the responsibility of the specifier, supplier and user to ensure compliance with the performance and requirements in this document, all other requirements and conditions of GIB Noise Control Systems, 2017, all applicable manufacturer s requirements, all required quality and durability standards, and all Building Code requirements. SEPTEMBER 2017 GIB HELPLINE 0800 100 442 OR GIB.CO.NZ FOR MORE INFORMATION GIB NOISE CONTROL SYSTEMS SUPPLEMENT 2
POLYESTER SOUND CONTROL INFILL The testing referred to in this Testing Statement related solely to noise attenuation and fire ratings, and no assurance or representation is made in relation to any other property or performance characteristic of any infill except as expressly stated in this document, and subject in all cases to product-specific information issued by the manufacturer. SEPTEMBER 2017 GIB HELPLINE 0800 100 442 OR GIB.CO.NZ FOR MORE INFORMATION GIB NOISE CONTROL SYSTEMS SUPPLEMENT 3
Issue Date March 2006 This information is an extract from the GIB Noise Control Systems literature March 2006. SPECIFIC DESIGN The design information set out in this literature is necessarily generalised and only applicable to normal situations. Specific acoustic design advice should be sought from an experienced acoustical engineer in less common situations. For instance, inner city apartment developments of more than 5 storeys would usually benefit from specific design since even minor optimisation in construction can result in appreciable cost reductions. Specific design is also required where a residential development is located in a business or industrial zone and a specified internal noise level must be achieved for compliance with a building consent. The information given in this publication is based on normal free flowing traffic as the noise source and different types of noise could change the noise reduction values given. In particular this information should not be used where the noise source is loud or amplified music. Specific design is required in this case. VARIATION IN SOUND RATINGS The ability of building materials to resist the transmission of sound is dependent on their density, thickness and stiffness. Generally speaking light and stiff materials have poor sound insulation properties because they allow sound at certain frequencies (near the so-called critical frequency) to transmit easily. Materials of similar thickness and weight can have different sound reduction performance if they have different critical frequencies. For example, laminated glass has a better sound reduction because it reduces the effect of the critical frequency by damping vibration and reducing the stiffness of the window. MULTI-STOREY BUILDINGS In multi-storey buildings typical of apartment developments there are fewer transmission paths than traditional, single occupant, single level houses. For instance in the case of a bedroom on a mid level there will be no significant external noise transmission through the roof or the floor since these are shielded by the apartments above and below. Because there are fewer transmission paths the overall noise reduction is greater than a house with roof and floor paths. This factor can be included in the design by using the partial system performances detailed for types A, B and C construction. Thus for the apartment with only a wall and window path the performance is about 3 dba higher than the overall system performance. Multi-storey buildings do not often use weatherboards as an external cladding. However, 6mm fibre cement board can be used as an equivalent to 20mm weatherboards. It should be noted that the noise level does not reduce significantly with height in multi-storey buildings even up to 30 storeys and so the same construction must be used on all levels. WINDOW TO WALL RATIO There is no optimum window to wall ratio. Generally speaking, from an acoustic point of view, the smaller the window the better as it is often the weakest MARCH 2006 GIB HELPLINE 0800 100 442 OR GIB.CO.NZ FOR MORE INFORMATION GIB NOISE CONTROL SYSTEMS SUPPLEMENT 4
ENVIRONMENTAL NOISE path and thicker glazing or double glazing is more expensive in comparison to other building systems. The newer types of laminated glazing using a PMM interlayer (e.g. Pilkington HUSH Glass) provide about a 3 dba improvement over similar thickness float glass. A 3 dba reduction would otherwise require an increase from 6mm to 10mm float glass. ASSUMPTIONS IN DESIGN The major assumption in design is that the noise spectrum is a traffic noise spectrum. The noise reduction may be a little more for industrial noise, which generally has more mid to high frequency, and less for low frequency dominated noises such as pubs or nightclubs etc. Another significant assumption is that windows are perfectly sealed. This is a reasonable assumption for aluminium joinery but a poor assumption for timber joinery. We would not recommend standard timber joinery for any noise reduction application above standard construction. Also all design assumes closed windows. Open windows will generally lower the noise reduction to between 10 and 15 dba. Fibre cement board (6mm) can be used as an equivalent to 20mm weatherboards. However, if a brick veneer is specified a slightly higher dba loss can be expected. Noise levels quoted are average levels. These are L eq for traffic noise, L dn for aircraft noise and L 10 for industrial noise. 5
ENVIRONMENTAL NOISE Knowing the environmental noise levels for the area will determine which construction type is most suitable to achieve the indoor noise level required. TRAFFIC NOISE The average L eq traffic noise levels quoted in the table below will assist in determining the likely noise levels faced when building within a certain distance of a particular type of road. AIRCRAFT NOISE L dn noise levels quoted are the average levels for aircraft noise. Each airport prepares a set of noise boundaries called the Inner Control Boundary and the Outer Control Boundary. These are based on the 65 dba L dn contour and the 55 dba L dn contour respectively. Outside the Outer Control Boundary no noise control is deemed necessary. Between the Outer and Inner Control Boundaries housing is a permitted activity but the walls and roof of the house must provide sufficient sound insulation to achieve a reasonable indoor noise level. Inside the Inner Control Boundary housing is generally a controlled or discretionary activity subject to meeting the internal noise levels. The relevant Local Authority sets the indoor level. The most common level is 45 dba L dn. These noise levels are subject to change from time to time. The building designer must consult the local authority to ascertain the required indoor level and consult the relevant planning maps to determine the aircraft noise exposure at the proposed building location. INDUSTRIAL NOISE L 10 noise levels quoted are the average levels for industrial noise. Generally when dwellings are built in an industrial or business zoned area the building must be built with sufficient sound insulation to reduce the noise level inside to a reasonable level, assuming that the industry next door is making the maximum noise level permitted by the District Plan rules for that zone. Often this reasonable level will be left to the acoustic consultant to determine. The usual indoor level used is a level of 35 dba for bedrooms at night and 45 dba for other habitable spaces during the day. The maximum noise level will vary from zone to zone and also from Local Authority to Local Authority. Generally the noise levels will be between 60 dba and 75 dba. Zonings are subject to plan changes and the building designer must consult the local authority to determine the current zoning and noise rules. ROAD TRAFFIC NOISE LEVELS (L eq dba) Average Daily Traffic Flows v/d = vehicles per day Distance from road edge to house facade Example 6 Lane Motorway 60,000 v/d 100 km/hr 4 Lane Motorway 25,000 v/d 100 km/hr 4 Lane Busy Urban Arterial Rd 20,000 v/d 60 km/hr 12m 72 dba 68 dba 66 dba 60 dba 25m 67 dba 63 dba 61 dba 55 dba 80m 62 dba 58 dba 56 dba 50 dba 150m 57 dba 53 dba 51 dba <50 dba Auckland Southern Motorway S.H.20 to Airport Mt Eden Rd, Ellerslie Panmure Highway Wellington Hutt Road Cable St, Wakefield St, Vivian St, Taranaki St Christchurch Northern Motorway Blenheim Rd, Riccarton Rd 2 Lane Urban Rd 6,000 v/d 50 km/hr 6
ENVIRONMENTAL NOISE (18-20 dba REDUCTION) TYPE A For external walls requiring a performance of 18-20 dba reduction the following construction can be used. In the example below the system initially has a higher performance of 24 dba but as windows, roof and floor are added, the performance decreases to give an overall system loss of 18-20 dba. STANDARD CONSTRUCTION (18-20 dba) REDUCTION SYSTEM PERFORMANCE (dba) LOSS As windows, roof and flooring are included Wall only 24 dba reduction Cavity construction as required 90mm timber wall framing 10mm GIB Standard Plasterboard Up to 20% of wall area 4mm float glass or up to 50% of wall area 7mm Pilkington HUSH Glass Wall and Window 20-22 dba reduction 10mm GIB Standard Plasterboard File: GIB-004-01-170 (18-20 dba reduction) - Type A 14 JUN 2017 (18-20 dba reduction) - Type A GIB-004-01-170 Concrete or 0.55mm profiled steel sheet or tile Wall, Window and Skillion Roof 19-21 dba reduction (This performance level applies to concrete floors) 13mm GIB Standard Plasterboard GIB Rondo metal batten File: GIB-004-01-171 (18-20 dba reduction) - Type A 14 JUN 2017 (18-20 dba reduction) - Type A GIB-004-01-171 10mm GIB Standard plasterboard 7
ENVIRONMENTAL NOISE (18-20 dba REDUCTION) TYPE A STANDARD CONSTRUCTION (18-20 dba) REDUCTION SYSTEM PERFORMANCE (dba) LOSS As windows, roof and flooring are included Concrete or 0.55mm profiled steel sheet or tile Wall, Window and Truss Roof 19-21 dba reduction (This performance level applies to concrete floors) 13mm GIB Standard Plasterboard 10mm GIB Standard Plasterboard 20mm particle board or oriented strand board Wall, Window, Roof and Timber Floor 18-20 dba reduction File: GIB-004-01-173 (18-20 dba reduction) - Type A 14 JUN 2017 (18-20 dba reduction) - Type A GIB-004-01-173 File: GIB-004-01-174 (18-20 dba reduction) - Type A 14 JUN 2017 (18-20 dba reduction) - Type A GIB-004-01-174 8
ENVIRONMENTAL NOISE (25 dba REDUCTION) TYPE B For external walls requiring a performance of 25 dba loss the following construction can be used. In the example below the system initially has a higher performance of 33 dba but as windows, roof and floor are added, the performance decreases to give an overall system loss of 25 dba. CONSTRUCTION FOR (25 dba) REDUCTION SYSTEM PERFORMANCE (dba) LOSS As windows, roof and flooring are included Wall only 33 dba reduction Cavity construction as required 90mm timber wall framing under external cladding minimum Up to 20% of wall area 7mm float glass or up to 50% of wall area 11mm Pilkington HUSH Glass Wall and Window 29 dba reduction under external cladding minimum Concrete Environmental or 0.55mm Noise profiled steel sheet or tile File: GIB-004-01-180 (25 dba reduction) - Type B (25 dba reduction) - Type B GIB-004-01-180 Wall, Window and Skillion Roof 19-21 dba reduction (This performance level applies to concrete floors) 12mm particle board or similar sarking 13mm GIB Standard Plasterboard GIB Rondo metal batten under external Environmental cladding minimum Noise File: GIB-004-01-181 (25 dba reduction) - Type B (25 dba reduction) - Type B GIB-004-01-181 9
ENVIRONMENTAL NOISE (25 dba REDUCTION) TYPE B CONSTRUCTION FOR (25 dba) REDUCTION SYSTEM PERFORMANCE (dba) LOSS As windows, roof and flooring are included Concrete or 0.55mm profiled steel sheet or tile Wall, Window and Truss Roof 26 dba reduction (This performance level applies to concrete floors) under external cladding minimum 13mm GIB Braceline GIB Noiseline 2 x 20mm particle board or oriented strand board Wall, Window, Roof and Timber Floor 25 dba reduction 6mm fibre cement or similar File: GIB-004-01-183 (25 dba reduction) - Type B (25 dba reduction) - Type B GIB-004-01-183 File: GIB-004-01-184 (25 dba reduction) - Type B (25 dba reduction) - Type B GIB-004-01-184 10
ENVIRONMENTAL NOISE (30 dba REDUCTION) TYPE C For external walls requiring a performance of 30 dba loss the following construction can be used. In the example below the system initially has a higher performance of 35 dba but as windows, roof and floor are added, the performance decreases to give an overall system loss of 30 dba. CONSTRUCTION FOR (30 dba) REDUCTION SYSTEM PERFORMANCE (dba) LOSS As windows, roof and flooring are included Wall only 35 dba reduction Cavity construction as required under external cladding minimum GIB Rail 90mm timber wall framing Up to 20% of wall area 11mm Pilkington HUSH Glass Wall and Window 32 dba reduction under external cladding minimum Concrete or 0.55mm profiled steel sheet or tile File: GIB-004-01-190 (30 dba reduction) - Type C (30 dba reduction) - Type C GIB-004-01-190 Wall, Window and Skillion Roof 31 dba reduction (This performance level applies to concrete floors) 12mm particle board or similar sarking 2 x 13mm GIB Rondo metal batten File: GIB-004-01-191 (30 dba reduction) - Type C (30 dba reduction) - Type C GIB-004-01-191 11
ENVIRONMENTAL NOISE (30 dba REDUCTION) TYPE C STANDARD CONSTRUCTION (18-20 dba) REDUCTION SYSTEM PERFORMANCE (dba) LOSS As windows, roof and flooring are included Concrete or 0.55mm profiled steel sheet Wall, Window and Pitched Roof 31 dba reduction (This performance level applies to concrete floors) under external cladding minimum 2 x 13mm 2 x 20mm particle board or oriented strand board 6mm fibre cement or similar Wall, Window, Roof and Timber Floor 30 dba reduction File: GIB-004-01-193 (30 dba reduction) - Type C (30 dba reduction) - Type C GIB-004-01-193 File: GIB-004-01-194 (30 dba reduction) - Type C (30 dba reduction) - Type C GIB-004-01-194 12
EXAMPLE INSULATING FOR ENVIRONMENTAL NOISE CONSTRUCTION TYPE C 30 dba REDUCTION When using Type C construction to control environmental noise, only the section facing the noise source needs to be specified Type C. The further away from the noise source the lower the dba loss system required. Noise source 30 dba reduction (construction Type C). The front wall and down the side walls of front rooms only facing the noise source 5 dba less than the construction for the wall facing the noise source. 25 dba reduction (construction Type B) 5 dba less than the construction for the wall facing the noise source. 25 dba reduction (construction Type B) 10 dba less than the construction for the wall facing the noise source. Construction Type A 18-20 dba reduction. Note: When using construction methods Type B or Type C, all of the roof and ground floor (timber floors only) must be fully constructed to that specification. i.e. no reduction relating to distance from noise source. 13