CSR Hebel Power Floor Design Guide

3.1 Typical Applications

Hebel PowerFloor systems detailed in this design and installation guide are joist floor solutions for detached residential, low rise multi-residential, commercial and industrial construction.

Fig 3.1. Residential Suspended Ground Floors

The floor applications consist of a Hebel PowerFloor panel connected to a steel or timber joist system forming a platform floor.

Fig 3.2. Residential Suspended First Floors

Figures 3.1, 3.2, 3.3 show typical applications for Hebel PowerFloor, for more details refer to Hebel Technical Update TU-009.

Fig 3.3. Commercial Floors – schools, offices and community centres

3.2 How to Use This Design & Installation Guide

Systems Index- Table 1

This allows the designer to quickly locate a system that combines the acoustic rating (R_w), approximate floor thickness (excluding joist height), floor covering type and ceiling system requirement.

System Components, System Properties & Design Considerations

These sections provide relevant background information to enable designers to plan and select appropriate Hebel PowerFloor systems.

Hebel PowerFloor System Pages

These pages provide detailed performance information to assist in the selection of an appropriate Hebel PowerFloor system for the application under consideration.

Architectural Specification

This material can be copied for inclusion onto working drawings or project specifications. This provides a pro-forma layout with fill in sections to quickly and easily create and customise project specifications.

Installation Diagrams and Fixing Instructions

General design and installation information is provided for the various systems available. For more detailed information contact your CSR Hebel representative. For further information on different joist types and their applications, please contact the joist manufacturer.

Selecting a System
STEP 1. Scan the ‘System Index’ for systems with the appropriate floor covering for the intended application.
STEP 2. Turn to the selected system page and select ceiling system that provides appropriate performance (FRL/R_w/R-Value).
STEP 3. Consult your chosen structural engineer to determine a joist size and spacing requirement.
STEP 4. Confirm structural adequacy. Contact the joist manufacturer, or your chosen structural engineer.
STEP 5. Confirm acoustic and thermal performance by contacting the appropriate project engineer.

Table 1. System index for CSR Hebel PowerFloor Systems

Hebel PowerFloor System Description	Floor Covering Type	Applications & Benefits	System Nº	Ceiling System	Rw	Approx Depth Excluding Joists (mm)	System Details Page Nº
	•Carpet •Medium duty underlay	• Carpeted floor with a high level thermal performance.	PF-001	Nil	33	90	16
				(a) CSR821	55	144
				(b) CSR829	58	160
				(c) CSR818	61	166
				(d) CSR826	57	147
	•8mm Ceramic tiles •Flexible adhesive •Waterproof membrane (not required in dry areas)	• Rigid floor system, with good thermal performance. Suitable for wet or dry areas.	PF-002	Nil	32	88	17
				(a) CSR821	54	142
				(b) CSR829	57	158
				(c) CSR818	60	164
				(d) 2x13mm Gyprock CD	57	155
	•8mm Ceramic tiles •Flexible adhesive •Concrete topping slab •Waterproof membrane	• Wet area applications where a finished level has to be built-up and/or a surface fall is required.	PF-003	Nil	37	95	18
				(a) CSR821	56	149
				(b) CSR829	59	165
				(c) CSR818	62	171
	•Vinyl sheet floor covering •Masonite underlay	• Inexpensive floor with a hard surface and high level of thermal performance.	PF-004	Nil	37	85	19
				(a) CSR821	58	139
				(b) CSR829	60	155
				(c) CSR818	62	161
	•19mm T & G hardwood flooring •70 x 35mm timber battens	• Attractive solid timber finish with a high level of thermal performance.	PF-005	Nil	37	129	20
				(a) CSR821	55	183
				(b) CSR829	58	199
				(c) CSR818	61	205

Note: Resilient mounts will help reduce footfall noise when using hard surface coverings such as tiles.

3.3 System Components

These components are compatible with timber and steel joists.

• Hebel PowerFloor Panel
• Floor Covering
• Proprietary Ceiling System
• Hebel Adhesive
• Fuller Max Bond
• Fasteners & Fixings
• Caulking

CSR Building Products Limited, guarantees only the products that are manufactured by CSR Hebel, not the components, products or services supplied by others.

Hebel PowerFloor Panel

The Hebel PowerFloor panel is available in a stock length of 1800mm x 600mm width, with a mass of up to 56kg/panel. Where necessary, panels can be cut on-site using a circular saw with diamond tipped cutting blade. The minimum recommended width of a cut panel is 270mm width and 900mm in length.

The panels are screw fixed and bonded to all floor joists except at panel butt joints. At butt joints, panels are fixed using two beads of adhesive, and the screws may be omitted. For further information on fixing Hebel PowerFloor panels, please refer to relevant construction details outlined in this guide.

Fig 1. Hebel PowerFloor Panel Cross Section

Floor Coverings

A range of floor coverings can be installed over the Hebel PowerFloor panels, such as, direct stick tiles, carpet and underlay, topping slab and tiles, timber (direct fix, floating or on battens) and vinyl over masonite.

Proprietary Ceiling Systems

The underside of Hebel PowerFloor can be lined with proprietary ceiling systems. These ceiling systems consist of combinations of components, such as furring channel, resilient mounts, clips, suspended steel framing, insulation, and plasterboard.

The most common combinations are detailed in the table below.

Further information on floor/ceiling systems is available through CSR Gyprock, or the publications, CSR Gyprock Fibre Cement Fire & Acoustic Design Guide (‘The Red Book‘), NºGYP500, and CSR Gyprock Ceiling Systems Installation Guide, NºGYP570.

Timber & Steel Support Systems

Timber or steel floor framing can be used to support the Hebel PowerFloor panels. The maximum allowable spacing of the joists is 600mm. The joists, bearers and other supports shall be sized in accordance with the framing manufacturer’s recommendations.

Note: The designer should allow at least 51kg/m² for the selfweight of the Hebel PowerFloor panel. A minimum joist flange width of 45mm is required.

Hebel Adhesive

Hebel Adhesive (supplied in 20kg bags) is used for gluing the panels together at all joints. Typically, panel joints are 2-3mm thick. Sufficient pressure is to be applied to the joint to ensure full coverage of adhesive in the joint. Adhesive is to be mixed to the proportions as stated on the bag.

Ceiling System Description	Ceiling System Components
	• CSR Resilient Mounts (Nº CSR1) screw fixed to every joist at 600mm maximum centres. • RONDO Furring Channel (Nº 129) at 600mm maxmum centres, clipped into resilient mounts • Bradford Glasswool Gold Batts R1.5 insulation infill. • 1 layer x 13mm GYPROCK Plasterboard CD fixed to furring channel.
	• CSR Resilient Mounts (Nº CSR1) screw fixed to every second joist at 600mm maximum centres. • RONDO Furring Channel (Nº 129) at 600mm maximum centres, clipped into resilient mounts • Bradford Glasswool Gold Batts R1.5 insulation infill. • 1 layer x 13 mm GYPROCK FYRCHEK Plasterboard CD + • 1 layer x 16mm GYPROCK FYRCHEK Plasterboard CD fixed to furring channel.Note : 13mm Gyprock Fyrchek plasterboard must be applied first.
	• RONDO Fixing Clip (Nº 226 or Nº 394) screw fixed to every second joist at 600mm maximum centes. • RONDO Furring Channel (Nº 129) at 600mm maximum centres, clipped into resilient mounts. • Bradford Glasswool Gold Batts R1.5 insulation infill. • 3 layers x 16mm GYPROCK FYRCHEK Plasterboard CD fixed to furring channel.
	• CSR Resilient Mounts screw fixed to every joist at 600mm centres. • RONDO Furring Channel (Nº 129) at 600mm maximum centres, clipped into resilient mounts. • 105mm Bradford Gold Insulation R2.0 GW insulation batts. • 1 layer x 16mm GYPROCK FYRCHEK Plasterboard CD fixed to furring channel.

Construction Adhesive

A 5mm (minimum) bead of Fuller Max Bond construction adhesive is applied to the top of the joists. Where panel ends butt together over a common joist, two beads of adhesive shall be applied. Ensure the surface is free of coatings and loose material that may inhibit bond.

Fasteners

The correct sized fasteners for the construction of the floor systems must always be used. Install screws as shown in the Hebel PowerFloor Panel Fixing Details section of this guide.

Screws for fixing Hebel PowerFloor panels to Timber Joists:

14-10 x 100mm MP Bugle Head Batten Screws or equivalent.

Screws for fixing Hebel PowerFloor panels to Steel Joists:

14-10 x 95mm Hex Head Self-tapping Screws or equivalent (no seal required).

This fastener is suitable for metal thickness <3mm. Refer to screw manufacturer’s guidelines.

Caulking

Hebel PowerFloor requires that all gaps at openings, penetrations and control joints be caulked to provide an airtight floor system that maintains acoustic, thermal,vermin and fire resistance performance. All gaps must be carefully and completely filled with an appropriate flexible polyurethane sealant, installed in accordance with the sealant manufacturer’s specifications.

Hebel Patch

Minor chips or damage to panels are to be repaired using Hebel Patch. Hebel Patch is available in 10kg bags.

Anti-corrosion Coating Agent

Reinforcement exposed when panels are cut shall be coated with a liberal application of Fentak.

3.4 System Properties

Structural Performance

Hebel PowerFloor systems can support a maximum uniformly distributed load of 5kPa, or concentrated (point) load of 1.8kN over a load area of 350mm² with joists at 600mm maximum centres, 3.9kN over a load area of 10,000mm². For loads outside this range, please contact CSR Hebel.

The designer should specify the magnitude of the gaps between the Hebel PowerFloor panel and structure. This gap will allow movement to release any confining stresses due to movement of the supporting structure.

Fire Resistant Levels

Australian building regulations express the fire performance of a floor/ceiling with the rating system called the ‘Fire Resistance Level’ (FRL). The FRL rating of the systems detailed in this guide are opinions issued by the CSIRO based on test results.

Testing has been conducted in accordance with the Australian Standard AS1530 : Part 4 ‘Fire Resistance Tests of Elements of Building Construction’.

The FRL rating consists of three performance criteria, structural adequacy/integrity/insulation. For example, the FRL of a floor may be expressed as 180/120/90. Where ‘180’ indicates a rating for ‘structural adequacy’ of 180 minutes, followed by ‘integrity’ for 120 minutes, and ‘insulation’ for 90 minutes. The PowerFloor system has fire resistance of 240 minutes from a fire source above the floor. For fire resisrance to a fire source below the floor a fire rated ceiling system must be installed.

Acoustic Considerations

Sound Ratings

Floor systems, consisting of the Hebel PowerFloor and other products, have been laboratory tested to establish their sound insulation characteristics. A laboratory test involves the installation of a system between two massive concrete rooms, which are normally well isolated from one another, so that only direct transmission is via the system.

A steady sound level of various frequencies is generated on one side and measurements taken on both sides. These measurements are made in one/third octave bands from 100Hz to 5000Hz. For each specified frequency, the sound transmission loss is calculated. To assist in communication the performance is conveniently expressed as a single number called the ‘Weighted Sound Reduction Index’ (R_w).

Weighted Sound Reduction Index (R_w)

Recently, Australian building regulations have adopted the International Standard Organisation acoustic rating system called the ‘Weighted Sound Reduction Index’ (R_w). The R_w value replaces ‘Sound Transmission Class’ (STC) as a measure of the acoustic performance of a wall. A correction figure of C_tr is added to the R_w value to better quantify the acoustic performance of the building system.

C_tr Adaptation Term

The normal rating of R_w more closely defines the acoustic performance for speech frequencies. Where low frequency sound insulation performance is important, as may be the case with traffic noise or music and DVD systems, then a correction factor is applied to the airborne sound rating (R_w) to differentiate the systems with good sound insulation to these frequencies. The factor is C_tr and it is a negative value. A system with good low frequency performance will have a value of say -4; a system with poor performance will have a value of say -12.

Impact Isolation Class (IIC)

The ‘Impact Isolation Class’ (IIC) quantifies the transmission of impact sound through a floor/ceiling system.

The test involves impacting the floor assembly with a standard tapping machine and measuring the sound level below in the same manner as described for the airborne sound insulation. Higher numbers indicate less sound is being transmitted. IIC is an American system and is now being replaced by L_n,w, which is the ISO equivalent.

L_n,w

This is the measure of the weighted and adjusted sound level below the floor when the tapping machine is operated above. In this case the lower the value the better the acoustic performance.

There is an approximate relationship between L_n,w and IIC, either can be subtracted from the numerical value of 110 to determine the other.

C₁ Adaptation Term

The rating by L_n,w appears to work well where carpets or floating floors are employed on concrete or timber framed floors. With hard floor finishes, particularly with timber joist floors, the low frequency performance may require further consideration by your acoustic consultant.

Test Reports

All test reports quoted in this guide have been issued by the CSIRO, National Acoustic Laboratory or other NATA Registered Laboratories. Testing has been conducted in accordance with the relevant Australian Standard at the time of testing.

Sound Transmission Estimates

Computer models are used to determine sound transmission estimates for specific configurations, known as ‘Acoustic Assessments’. The computer model predicts the R_w performance expected from the laboratory test on the system, with a 96% confidence limit of ±2.5 db.

Performance – Laboratory vs Field.

When selecting the appropriate Hebel PowerFloor system, the designer or specifier must be aware that the laboratory R_w values are always higher than the field measured values (R_w). This is due to the field conditions, such as flanking paths, air leaks, floor frame construction type and stiffness, etc., which can be introduced by careless building design or construction. To avoid significant reductions in acoustic performance published construction details must be followed completely. Independent specific advice and confirmation should be sought for specific projects where the presence of flanking paths or any other acoustic effect may affect field performance.

Typically, the field performance of a system will be 2 to 5 R_w units lower than the laboratory performance, and allowance should be made for this by the acoustic consultant during the selection of the floor system.

Thermal Performance

Thermal performance is concerned with the energy retention or loss characteristics of a building system. One of the primary design objectives in planning a cost effective building is to provide a comfortable living/working environment for the building’s inhabitants. Exploiting the inherent thermal qualities of Hebel AAC enables the designer to achieve this objective.

R-Value Rating

The energy demand can be minimised by controlling the heat transfer, which is heat flowing from a hot region to a colder region, through a building system. The thermal resistance of a building system is expressed as the R-Value. The R-Value of the system is the sum of the R-Values of the individual components.

Thermal Masses & Insulation Property

Several comparative studies have been conducted to investigate the benefits of incorporating Hebel AAC walls in place of conventional wall systems or thermal mass. A common trend was the lower heating and cooling energy consumption and smaller mechanical equipment required to maintain a comfortable living environment, especially with regards to regions of mainly cold weather.

The benefit of thermal mass is that it tends to buffer the effects of external temperature swings. Thermal mass coupled with the insulation quality of Hebel AAC, which impedes the flow of heat through the floor, gives an excellent barrier to a variable outside elements.

Thermal Integrity

Poor thermal integrity, due to bad construction practices can also significantly affect the comfort performance, as poor sealing and gaps allow air to infiltrate as drafts. The inherent construction tolerances of Hebel PowerFloor provides a floor with a low infiltration rate and good thermal integrity.

3.5 Design Considerations

Acoustics

Placement of insulation in the ceiling cavity can enhance the sound insulation performance of a floor/ceiling system.

A carpet/underlay floor covering incorporated with Hebel PowerFloor will provide the best impact sound resistance. For hard surface floor coverings, we suggest using a floating floor and/or an independent ceiling system, incorporating resilient mounts or resilient furring channels.

For ceilings that incorporate resilient mounts or resilient furring channels, flanking sound paths through adjacent walls are common, especially in timber framed buildings. To maintain R_w and IIC ratings, the wall linings may also need to be resiliently mounted.

For multi-tenancy buildings, providing a control joint at the party wall will break a flanking path and maintain acoustic amenity.

Alternative Framing

Alternative support framing systems including steel, and composite steel/timber joists, laminated timber joists, and trussed plywood web joists may be used without reducing the system FRL rating for a fire source ‘from above’. The design of joists shall allow for temperature effects. Alternative support framing systems may affect acoustic performance, and advice from an acoustic consultant is recommended.

Penetration Restrictions

Penetrations are required to accommodate services, such as waste pipe-work, water pipe-work, and air conditioning ductwork, etc.

Hebel PowerFloor can accommodate an 80mm maximum circular penetration without a reduction in structural performance. Multiple penetrations in the same panel are to be in a straight line, parallel to the long edge of the panel.

For large or clustered multiple penetrations, additional joists or bridging should be included for support of the panel in this area. Refer to the ‘Penetration & Notching Details’ section of this guide.

All penetrations are a potential source for water ingress or air leaks, and should be sealed with an appropriate flexible fire rated sealant or proprietary collar.

Control Joint Layout

Control joints are a necessary part of Hebel PowerFloor. Control joints provide a region in which to relieve stress due to movement of the structural system, and to control the location where movement can occur without a detrimental effect on the floor finish.

Recommended locations for control joints are:

• Typically at a max. spacing of 6000mm.
• Over lines of support for the joists. Refer to Fig 6.3.3.
• Located at lines of bracing, ensuring a diaphragm between the bracing lines
• Located at changes in joist orientation.

Wet Area Floor Construction

All wet areas require a waterproof membrane layer over the Hebel PowerFloor panel.

Waterproofing membranes shall be nominated by the designer or specifier, and installed in accordance with manufacturer’s recommendations.

Serviceability Behaviour

The deflection limits of the floor are governed by the adopted joist size. As a guide, the following typical deflection limits provide acceptable behaviour and dynamic response:

• Dead Load (DL): span/300 or 12.5mm max.
• Live Load (LL): span/360 or 9mm max.
• DL & LL: span/250.
• Dynamic Response: 2mm max. under a 1kN point load.

Concentrated Loads

For concentrated loadings, such as a loadbearing wall or point loads, the designer should ensure additional joists or blocking are provided beneath the wall or bearing plate. This will reduce the localised bearing stress. Bearing stress in the AAC shall be limited to 1.0MPa.

Note: The designer should select appropriate deflection limits to suit individual projects.

Bracing Walls

For bracing walls parallel to joists, a joist shall be positioned beneath the wall. For bracing walls perpendicular to joists, blocking shall be positioned beneath the wall. Blocking shall have a minimum width of 45mm. Bearing stress in the AAC shall be limited to 1.0MPa.

Panel Support

All Hebel PowerFloor panels are to start and finish on a joist. Panels must be joined on a joist.

3.6 Building Regulations

Intertenancy Floors

Floors constructed between separate tenancies are required to achieve a minimum acoustic and fire performance.

Acoustic Performance

For Class 2 and 3 Building with floors separating sole occupancies the following minimum acoustic requirements are described in the BCA:

• Airborne Sound Transmission: R_w + C_tr ≥ 50
• Impact Sound Transmission: R_n,w + C_I ≤ 62

Or, measured in-situ performance of:

• Airborne Sound Transmission: D_nT,w + C_tr ≥ 50
• Impact Sound Transmission: L_nT,w + C_I ≤ 62

Fire Performance

For Class 2 and 3 Building with floors separating sole occupancies the following fire requirements are described in the BCA:

• FRL – 90/90/90 (Structural Adequacy/Integrity/Insulation)

Please refer to section C of the BCA for certain exemptions to the above fire rating requirements.

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 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 : 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; and Energy Efficiency.

This design guide presents tables, charts and information necessary to design a Hebel PowerWall 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.