• Acoustic Performance: Significantly reduced sound transmission between units and rooms.
• Good Impact Noise   Resistance: 75mm Hebel Intertenancy 001 has  discontinuous construction and can be selected to reduce the transfer of impact noise.
• Fire Protection: Tested systems have very good fire rating properties.
• Lightweight: Lighter loads on structures compared to masonry block, for equivalent Rw + Ctr rating.
•  Slender Walls: Wall thicknesses range from 275 to 325mm.
• Cost Effective: Cost savings compared to traditional masonry construction.
• No Wet Trades: Less mess and a cleaner, safer work area.

• Less Wastage: Greatly reduced waste, as panels are available in a range of standard lengths. This allows for best suited panel length selection,   which eliminates or reduces off-cut waste.

• Speed of Construction: Fast installation and assembly speeds with smaller construction crew requirements.
• Security: Steel reinforced AAC panels provide a high degree of security between units.
• Thermal Resistance: Excellent thermal resistance.

• Technical Support: Competent technical staff can assist with    systems  information. The following images show a typical two storey Hebel Party Wall installation.

Where it is proposed to construct single dwellings side-by-side on a single allotment the internal wall between dwellings is a fire separating wall as defined in the BCA. The fire separating wall must start from the ground level (top of concrete footings or top of floor slab) and achieve a 60/60/60 FRL if load bearing, or –/60/60 FRL if nonload bearing. The wall must go to the underside of a non-combustible roof covering and any gaps be filled with fireresisting material as described in Detail 3.7.1.11 of Volume Two of the BCA.

Dwellings Constructed Side-By-Side on Separate Allotments

Where it is proposed to construct single dwellings side-by-side on separate allotments, or if subsequent subdivision is proposed, the wall might also be considered an external wall and each dwelling may be required to have its own wall starting from the ground level (top of concrete footings or top of floor slab) and each achieving a 60/60/60 FRL if load bearing, or –/60/60 FRL if non-load bearing. Contact your local authorities, as there may also be applicable legislation or discretionary powers available to vary these provisions.

Dwellings Constructed SideBy-Side on a Single Allotment Where Subdivision May Subsequently Occur

Where it is proposed to construct single dwellings side by side on a single allotment and it is known that subsequent subdivision will occur, or that subdivision might occur (and this will probably apply to most multi-dwelling developments) then, after subdivision, the internal fire separation wall might also be considered an external wall and each dwelling may be required to have its own wall starting from the ground level (top of concrete footings or top of floor slab) and achieving a 60/60/60 FRL if load bearing, or –/60/60 FRL if non-load bearing. Contact your local authorities, as there may also be applicable legislation or discretionary powers available to vary these provisions.

Hebel PartyWall Solutions in tiered applications

Where the internal fire separation wall extends beyond the roof line on one side only and becomes an external wall, contact CSR Hebel Engineering Services for advice on PowerWall external wall solutions.

Compliance with the Building Code of Australia (BCA)

All building solutions, such as walls, floors, ceilings, etc. must comply with the regulations outlined in the Building Code of Australia (BCA) or other authority.

The BCA is a performance based document, and is available in two volumes which align with two groups of ’Class of Building’: Volume 1 – Class 2 to Class 9 Buildings; and Volume 2 – Class 1 & Class 10 Buildings – Housing Provisions. Each volume presents regulatory Performance Requirements for different Building Solutions for various classes of buildings and performance provisions.

These Performance Provisions include:

• Structure
• Fire Resistance
• Damp & Weatherproofing
• Sound Transmission & Insulation
• Energy Efficiency

This design guide presents tables and information necessary to design a Hebel PartyWall installation that complies with the Performance Requirements of the BCA. The designer must check the adequacy of the building solution for Performance Requirements outlined by the appropriate authority.

STEP 1: Scan the ‘System Selection’ table for the required characteristics.
STEP 2: Turn to Section 6.0 and select the appropriate Hebel PartyWall solution.
STEP 3: Confirm the selected Hebel PartyWall solution has adequate Fire Resistance Level (FRL) rating and acoustic performance level.
STEP 4: If an appropriate Hebel PartyWall can not be selected, contact CSR Hebel Engineering Services for advice.

 System Selection for Hebel Low Rise Party Wall

• 75mm Hebel Intertenancy 001 has been assessed to comply with the BCA requirements for ‘Discontinuous Construction’.
• This table must be read in conjunction with all the information provided in this Design Guide, NºHBLA228 LRPW January 2008, and acoustic opinion (PKA – A034) provided by PKA Acoustic Consulting P/L and fire assessment (WFRA – 45771.3) provided by Warrington Fire Research (Aust) Pty Ltd.
• Selection of a Hebel PartyWall from Table 6.1 should be taken with specialist consultant’s advice.

Note: * Timber framing requires studs at 450mm maximum spacings and mid-height nogging (refer PKA – A034), and for steel framing, frames to be designed in accordance with AS3623 or AS4600.

2:  75mm Hebel Intertenancy 002

• This table must be read in conjunction with all the information provided in this Design Guide, NºHBLA228 LRPW January 2008, and acoustic opinion (PKA – A044) provided by PKA Acoustic Consulting P/L., and Fire assessment (WFRA – 45772.1) provided by Warrington Fire Research (Aust) Pty Ltd.
• Selection of a Hebel PartyWall from Table 6.2 should be taken with specialist consultant’s advice.
•75MM HEBEL INTERTENANCY 002 CAN NOT BE USEDWITH STEEL FRAMING.

Sound Transmission & Insulation

Overview

The Building Code of Australia (BCA) presents the Performance Requirements for sound insulation ratings. The sound insulation ratings set minimum values to consider two types of sound: airborne sound and impact generated sound. The Performance Requirements for airborne sound insulation and impact sound insulation ratings are dependent upon the form of construction (i.e., walls or floors), Class of Building, and the type of areas being separated. The airborne sound performance requirement is a value that could be the weighted sound reduction index (Rw) or weighted reduction index with spectrum adaptation term (Rw +Ctr ). The impact sound performance requirement is a value called the weighted normalised impact sound pressure level with spectrum adaptation term (L n, w + Cl).
The BCA does provide Performance Requirements for the airborne sound and impact generated sound insulation ratings for a party wall. Refer to Tables 6.1 and 6.2 for sound
insulation resistance level of the Hebel PartyWall systems.

Impact Sound Performance

Impact sound is caused by vibrations, which are transferred directly through the wall and re-radiated as sound in the adjacent room. These sound vibrations can be generated by actions such as closing of a cupboard door.

The transfer of impact sound can be minimised by ensuring no mechanical connection exists between the two sides of the wall. For impact rated walls the new BCA requires walls to be of ‘discontinuous construction’. This refers  to a wall maintaining a minimum 20mm cavity between two separate leaves except at the periphery.

Note: For gap widths ≤ 20mm, CSR Hebel has obtained expert opinion that discontinuous construction performance will not be compromised

Acoustic Performance Design Recommendations

1) CSR Hebel recommends engaging a specialist acoustic consultant on a project-by-project basis to provide design advice, confirmation of anticipated field performance,
detailing and installation inspections.

2) When selecting the appropriate Hebel PartyWall, the designer or specifier must be aware that the laboratory Rw values are almost always higher than the field measured values. Therefore, allowances should be made for the lower expected field values during the selection of the system.

3) Separate advice from a specialist acoustic consultant should be sought to determine the effect on acoustic performance due to any changes to the Hebel PartyWall systems, and any required modification of the installation details pertaining to the systems.

4) Increasing of cavity widths, using higher density or thicker insulation or plasterboard, will generally maintain or increase the acoustic performance of the Hebel PartyWall.

5) The acoustic performance values of the Hebel PartyWall systems shown in Tables 6.1 and 6.2 are a guide only as to consistently achievable field performance. They do not constitute a field performance guarantee as factors such as the presence of flanking paths, quality of installation of the system, on-site detailing of junctions, room shapes and size, etc can significantly affect field performance. Maximising the field performance depends on the following factors:

• The systems are installed in accordance with the manufacturer’s standard installation details.
• Good quality installation practices including the sealing of all junctions and joints and maintaining specified clearances.
• The systems are installed with all junctions acoustically sealed so that negligible sound transmission occurs at these points.
• Flanking paths are eliminated and the structures into which the systems are installed are capable of allowing the nominated rating to be achieved.
• Site testing conditions.
• To minimise the transfer of sound through the Hebel PartyWall system into the adjacent unit, it is suggested that a control joint be provided to break the mechanical path for the transmission of impact sound and other vibration.

* NOT SUITABLE FOR STEEL FRAME CONSTRUCTION. NOT DEEMED DIS CONTINUOUS CONSTRUCTION.

Note: Detailing of elements, such as flashings, gutters, capping, roofing, etc. shown in this section are for indicative purposes only.

Vertical Cross Section of 75mm Hebel Intertenancy 002

*Not suitable for steel frame construction. Not deemed discontinuous construction.

2 Construction Details for 75mm Hebel Intertenancy 002

*Not suitable for steel frame construction. Not deemed discontinuous construction.

Junction Details for 75mm Hebel Intertenancy 002