External Walls

Hebel PowerPanel a revolutionary way to build

The Heble PowerPanel System

The Hebel PowerPanel Systems for Houses & Low Rise Multi-Residential External Walls has been designed for homes built using either timber steel framing and can be used in new dwelling construction, extensions or re-cladding. The system consists of 75mm thick, steel-reinforced Hebel PowerPanels, fixed vertically to horizontal battens attached to the load-bearing frame. For quick, clean construction.

Hebel PowerPanels can be ordered in the stock lengths of 2400mm, 2700mm and 3000mm and in widths of 300mm and 600mm. The 600mm wide PowerPanels are also available in the additional lengths of 1200mm 2550mm, 2850mm and 3300mm.

Designing an external wall using Hebel PowerPanel.

Design Process

This section outlines the design process for determining the adequacy of Hebel PowerPanel.

1. Determine the wind category, stud framing layout and PowerPanel height requirements.
2. Design Criteria. Where required identify the BCA Performance Requirements:
   • Fire Resistance Level (FRL).
   • Sound insulation performance (Rw values).
   • Energy Efficiency (R-Value).
3. The flowchart below can be used to select a type, spacing and quantity of Top Hats and fixings to suit requirements.
4. Select insulation and/or sarking material to suit energy efficiency and condensation requirements.
5. Check adequacy of sound insulation and fire resistance level.
6. Complete detailed design and documentation.

Compliance with the Building Code of Australia (BCA)

All building solutions, such as walls, floors, ceilings, etc. must comply with a regulations outlined in the BCA or orther authority.

The BCA is a performance based document, and is available in two volumes which align with two groups of "Class of Building":

Volumn 1 - Class 2 to Class 9 Buildings; and

Volumn 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; and Energy Efficiency.

This design guide presents tables, charts and information necessary to assist in the design of a system incorporating Hebel PowerPanel that complies with the Performance Requirements of the BCA. The designer must check the adequacy of the building solution for Performance Requiremtns outlines by the appropriate authority.

Structural Provisions

Overview

The Hebel PowerPanel system consists of Hebel PowerPanel secured to the framing via horizontal steel Top Hats. This section provides the basic information on the selection of Top Hat spacings for a given stud spacing and wind category, as well as considerations to assist the designer in determining the appropriate wall configuration.

The design information presented in Table 1.3 to 1.7 has been determined for a following Top Hat types:

• Rondo 303 - Rondo Building Services Pty Ltd.
• Lysaght Topspan 22 - Bluescope Steel Ltd.
• FastStud 24TH42.

For other brands or types of Top Hats, contact the manufacturer for design information. Minimum performance requirements for the metal studs, Top Hats, fixings and Hebel PowerPanel have been provided to assist the designer.

IMPORTANT: The design and approval of the structural framing (cold-formed steel or timber) is to be provided by the framing product manufacturer and/or project engineer.

Principles of Design

The principles on which the design is based include:

1. The lateral wind loads applied to the PowerPanels are transferred into the horizontal Top Hats, then to the stud frame, which should be designed in accordance with the relevant Australian Standards for the imposed loads. The frame should be designed for all bracing and hold-down requirements.
2. The design of the stud frame shall consider the weight of suspended PowerPanels (such as the upper storey of two-storey construction).
3. The system is not considered as cavity construction, as the Top Hat clearly bridges the cavity, hence the details show the necessity of sealing the windows and door frames, as well as applying a water resistant external coating.
4. The system specifications vary with wind load. The notation used in AS1684 Residential Timber Framed Construction has been adopted.
5. The localised effects of wind around corners of building have been considered in the design and included in the tables. The extent of this effect is discussed towards the end of this section.

- Criteria for Corner Panels

Due to the increase of wind load around the corners of building, extra Top Hats and screws may be necessary (N3 and greater) for a distance of 1200mm in each direction from the corner.

Tables 1.3 to 1.7 identify the installation criteria in these areas, in the columns titles "Panel Location - Corner".

- Cyclonic Loading Effects

Hebel PowerPanel for Detached Houses & Low Rise Multi-Residential External Walls has been tested at the James Cook Cyclone Structural Testing Station (Report No. T5 444) in Townsville. The pullout capacity of the screw into the back of the Hebel PowerPanel is the critical element in the design. The results from the cyclic testing showed that the system, in particular the pullout load of the screw, is unaffected by the cyclic loading. The detailing presented in this design guide is satisfactory for cyclonic areas.

- Earthquake Loads

Earthquake loading has not been considered in this design guide.

Design Tables

This is section presents tables to assist the designer in the selection of the number of Top Hats and number of screws for securing the Hebel PowerPanel to the framing, for a given wind category.

IMPORTANT: The wind category is to be used as a guide. The designer should check the project wind pressure against the valves given in the tables.

Stud Frame - Steel or Timber

The stud frame shall be designed by the stud manufacturer or appropriate project engineer. Hebel PowerPanels are a masonry product and the support structure should be designed to provide suffieienct stiffness.

The steel stud frame shall be designed and constructed in accordance with AS3623 and AS.NZS4600 (BCA Performance Requirement).

The timber stud frame shall be designed and constructed in accordance with AS1684.

Steel Top Hat

Hebel Top Hats are provided in nominal widths of 24mm and 35mm and have been designed and constructed in accordance with AS3623 and AS/NZS4600 (BCA Performance Requirement) with performance requirements for the Top Hats, of:

- Properties:

• Cold-fomed steel Top Hats.
• Minimum thickness 0.42mm BMT.
• Minimum yield strength 550MPa.
• Coating class Z275 (see Durability).

Panels Supported at Base

Hebel PowerPanel

Design procedures for the verification of wall systems consisting of Hebel autoclaved aerated concrete (AAC) PowerPanels generally follow the design principles outlined in Australian Standard AS3600 - Concrete Structures, with the exception of Cover requirements for durability and development length for reinforcement.

The strength design of the Hebel PowerPanels has been carried out using the Transformed Section Theory, as detailed in the text book, "Reinforced Concrete" by Warner, Rangan and Hall (Longman Cheshire). The load carrying capacity of the Hebel PowerPanel is influenced by several factors, such as:

• Imposed action (wind).
• Lateral stiffness of the supporting structure (lightweight structural (cold-formed)steel framing).
  • Stud size and spacings.
  • Deflection Limit.
• Height of the wall.
• Number and spacing of the Top Hats.
• Number of screw fixings considered effective.

Fixing

Table 1.8 outlines the connection type and requirements for constructing Hebel PowerPanel detailed in this design guide. The project engineer or framing manufacturer is responsible for specification of alternative details. The minimum performance requirement of the screw is:

Minimum screw coating class in accordance with AS3566:Class 3. (Refer Section 6.0 for Durability).

Design Considerations

Structural Framing Design

The use of Hebel PowerPanel in two-storey construction involves a number of design issues that require attention. In conjunction with the following refer to the Construction Details in Section 16.3 & 16.7. Note, when PowerPanels are suspended from the stud frame the project engineer shall design the frame to support the weight of the PowerPanels.

Design Tip

In order to reduce the load of the upper storey PowerPanels and make installation easier, the lower storey PowerPanels should be specified as 2700mm/3000mm in length and the upper storey PowerPanels as 2400mm in length. The vertical dimensions can be adjusted to suit.

Structural Framing Design for Two Storey Construction

The use of Hebel PowerPanel in two-storey construction involves a number of design considerations that require attention.

Note: when PowerPanels are suspended from the stud frame the project engineer shall design the frame to support the weight of the panels.

Steel Joists or engineered timber joists (<=1% shrinkage)

Note, lower storey panels are to bear on the slab edge. However, consideration should be given to the sectional size of the lintels over openings on the lower storey. As the details reveal, only a dummy control joint (solid 6-10mm packers, backing rod and polyurethane sealant join) is required at the horizontal PowerPanel junction between the upper and lower panels. The panel support packer should consist of a durable material that will not degrade during the life of the structure.

Timber Frame Construction (>1% shrinkage joist).

Movements in the order of 25mm can occur in a two storey timber frame with a timber first floor. The fixing method used in Hebel PowerPanel does not allow for this extent of differential movement between the external skin and the timber frame.

The allowances for shrinkage of timer framing in BCA 2011 Vol.2, Section 3.3.1.10, by providing gaps between framing and masonry should be adopted as a minimum.

It is therefore recommended that the upper storey PowerPanels be installed 35mm clear of the lower storey panels. During construction a temporary packer is used to separate the panels and is then removed after the panels have been fixed. An architectural trim (feature moulding) must be used to hide the horizontal control joint.

The impact of this construction is to load the lower storey frame with the weight of the upper storey panels. In effect, an extra 51kg/m² (for the weight of the upper panels) is being added to the load already carried by the timber frame. The load approximates 1.2kN/m (2.4m wall height).

To simplify the design implications of this extra load, it is recommended to add an extra 1.4m of tributary width for a 90kg/m² Tile Roof load (for 2.4m upper wall heights) for the design of the lower storey frame and timber lintels, when using AS1684. - Cyclonic or non-cyclonic areas.

Bracing of the Building

The walls of the dwelling should be braced using steel cross bracing wherever possible, to allow the fixing of the PowerPanels without the need for additional packing.

Ply or sheet bracing should be used on the external wall, if the walls are too short for the steel cross bracing (Refer AS 1684 - Cyclonic or non-cyclonic areas). In this case, the full length of the wall should be sheeted to prevent misalignment of the PowerPanels.

Alternatively, localised strips of the sheeting can be fixed to the intermediate studs, between the areas of full sheet bracing, to maintain the PowerPanel alignment. All fixing is only from the outside, except on boundary walls. The extent of the bracing should be determined by the frame designer or project engineer.

*Note: Minimum screw embedment depth into timber frame must be 25mm

Design & Detailing Considerations

Building Setout

Hebel PowerPanel is principally designed for modular construction. The full benefit of savings in time and cost will be fully realised when the construction is designed to suit a 300mm module. In principle, thoughtful setout on the drawing board will minimise the site-cutting of PowerPanels, which is time consuming and wasteful, as compared to the installation of stock PowerPanels.

External Wall Height

Typically the external wall height is the distance from the base of the slab step down up to 50mm above the height of the eaves lining.

Window and door heights should also be considered when determining panel layout. Typically a 300mm distance below or above door or window heights is desirable.

Wall Length (Horizontal Dimensions)

Although not as critical as the wall height, the wall length designed to 300mm dimensions will help reduce waste.

Termites

It is the builder's responsibility to ensure that all council and Australian code requirements are fully adhered to in regard to design of the house for precenting termite attack. The construction details contained in this guide do not attempt to fully address the issues, due to the variation of requirements from state to state. Hebel Power Panel is ideally suited to the exposed edge method of perimeter protection. BCA 2011 Vol. 2 Part 3.1.3 deals with termite risk management and the reference code is AS3660.

Footings

Footings for Hebel PowerPanel should comply with convertional masonry veneer construction as specified in Australian Standars AS 2870. This is a minimum requirement. Local engineering advice should always be sought, especially in areas of highly reactive ground conditions.

Movement Control Joints

During the life cycle of a building, the building and the materials that it is constructed from will move. These movements are due to many factors working together or individually, such as support structure movement (lasteral sway or vertical deflection). thermal expansion and contraction and differential movements between materials. This movement, unless relieved or accommodated for, will induce stress in the materials, which may be relieved in the form of cracking. To accommodate these movements and relieve any induced stresses, which could potentially crack the wall, movement joints need to be installed.

• Control Joints are provided to relieve the induced stresses resulting from thermal expansion or contraction of the AAC, or differential movement between the ACC and another material or structure, such as abutting walls or columns of concrete or brickwork. Control joints can delineate coating shrinkage breaks.

Vertical control joints should coincide with control joints in the supporting structure and anywhere that significant structural movement is expected, where the wall abuts a vertical structure, such as an existing building, or adjacent to large openings.

This design guide proposes minimum widths for the movement joints. The project engineer shall determine if the joints are sufficient to accommodate the movement of the specific project building. Typically the vertical joint is nominaly 5-10mm wide and filled with an appropriate backing rod and flexible polyurethane sealant.

IMPORTANT: At all control joints, the Top Hat should be discontinuous to allow for the effective movement of the building at these locations.

A horizontal control joint is required beneath slabs or angles to accommodate any expected deflection. The magnitude of the deflection must be verified by the building designer. Typically, the horizontal joint is nominally 10mm - 20mm wide and filled with an appropriate polyurethane sealant.

Condensation

Condensation is a complex problem, and can occur under a variety of conditions, not just cold conditions. Literature on this subject available from CSIRO/BRANZ/ASHRAE and must be consulted when building in areas where condensation is likely to occur.

In these cases, the appropriate use of a sarking as a vapor barrier or as thermal insulation, or both, can be effective in controlling condensation.

Penetrations

Small Service penetrations throught the PowerPanel should allow for differential movement between the powerPanel and the service. All penetrations are a potential source for water ingress and should be sealed with an appropriate polyurethane sealant.

Windows

The builder should also ensure that the reveal size is correct to suit PowerPanel.

The sizes below typically apply to aluminium framed windows. If timber windows are being used similar tolerances and guidelines apply.

Durability

Overview

Durability means the capability of a building or its parts to perforrm a function over a specified period of time. It is not an inherent property of a material or component. It is the outcome of complex interactions among a number of factors, including:

• The service conditions
• Material characteristics
• Design and detailing
• Workmanship
• Maintenance

The following sub-sections of the durability topic are written in order to provide general guidelines in how best to provide, enhand and maintain adequate durability of Hebel PowerPanel.

Maintenance & Enhancement of Durability

The durability of Hebel PowerPanel can be enhanced by periodic inspection and maintenance. Inspections should include examination of the coatings, flashings and sealants. Paint finishes must be maintained in accordance with the manufacturer's recommendations. Any cracked and damaged finish or sealants, which would allow water ingress, must be repaired immediately by recoating or resealing the effected area. Any damaged flashings or PowerPanels must be replaced as for new work.

The durability of the system can also be increased by using Class 4 fixings throughout, additional treatment of steelwork, and by painting all exposed sealants to the sealant manufacturer's recommendations.

Coastal Areas

Hebel PowerPanel can be used in coastal areas with additional precautions to ensure salt does not build up on the surface of the wall. For buildings, which are 200m to 1000m from a shoreline or large expanse of salt water, such as, Swan River (west of the Narrows Bridge), Sydney Harbour (east of the Harbour Bridge or Spit Bridge), one of the following is required:

• A horizontal and vertical movement joints must be appropriately caulked; or
• All walls must be sufficiently exposed from above so that rain can perform natural wash-down of the wall; or
• Walls, which are protected by soffits above, must be washed down twice per year, to remove salt and debris build-up, particularly at the joints.
• In all cases, Class 4 or stainless steel screws must be used.
• For buildings less than 200m from the shoreline as defined above, Hebel does not recommend that Hebel PowerPanel be used without project specific consultation with Hebel Engineering Services.

Hebel PowerPanel

Hebel PowerPanel has many characteristics which make it a vary durable product, including:

• Will not rot to burn.
• Is not a food source for termites.
• Unaffected by sunlight.
• Not adversely affected over normal temperature ranges.
• One quarter the weight of conventional concrete.
• Solid and strong with corrosion protection coated steel reinforcement.

Durability of Components

It is the responsibility of the building designer to ensure that the components, such as screws, Top Hat battens and other steel components, have the appropriate corrosion protection to be able to maintain their strength and integrity to suit the required design life of the project.

IMPORTANT:Termite treated timber frames (such as LOSP treated frames) may require sarking to precent corrosion of steel components. Please refer to frame manufacturer for compatibility.

CCA treated pine frames have a deleterious effect on the Top Hat coatings, which can lead to corrosion. Where timber is CCA treated, provide a barrier between Top Hat and timber member. Refer to frame manufacture for compliance with the frames compatibility with steel Top Hats and screw fixings.

When assessing durability the following documents can be referred to for guidance:

• ABCB Guideline Document - Durability in buildings: 2003.
• AS/NZS 2312: 2002 - Guide to the protection of structural steel against atmospheric corrosion by the use of protective coatings.
• ISO 9223: 1992 - Corrosion of metals and alloys - Corrosivity of atmospheres - Classification.
• AS3566: 2002 - Self drilling screws for the building and construction industries.
• AS2331 Series.

Reference to AS3566 should always be adhered to when selecting the screws corrosion resistance classification.

Wall Frames

Steel Frames

The designer needs to ensure that the steelwork Hebel AAC products have adequate protective systems to ensure that durability is maintained. The duraility of the stud frame can be enhanced by the provision of a membrane, such as sarking. The manufacturer of the steel stud frame can provide guidance on the appropriateness of this solutions on a project-by-project basis.

IMPOTRANT: The steel frame requirements outlined in the BCA Vol. 2, Part 3.4.2 should be considered in conjunction with steel frame design and construction advice from the steel frame manufacturer. These requirements consist of minimum protective surface coatings with restrictions on the location of the building and exposure condition of the steel frame.

Timber Frames

Information on the durability design of timber structures and components can be obtained from documents such as:

• AS 1720.1 Timber Structures, Part 1: Design Methods.
• AS 1684 Timber Framing Code.
• State timber framing manuals.
• AS 4100 Steel Structures.
• AS 3660 Subterranean Termites.

Fire Resistance Performance

Overview

The Hebel PowerPanel System can be subjected toa fire loading as the result of either an external fire source, or an internal fire source. When the wall requires a fire resistance level (FRL) rating, Hebel provides the following guidance.

External Fire Source

For an external fire source, the excellent fire resistance qualities of the Hebel PowerPanel protects the structural support framing, and provides a high fire resistance level for the Hebel PowerPanel System.

NOTE: The FRL rating of the wall can be affected by the penetrations and the method adopted to protect these penetrations. Afire collar with a -/120/120 FRL rating will govern the FRL of the wall, even if the wall configuration has a FRL rating of -/180/180. Where required, the performance of the external coating when subjected to a fire loading shall meet the appropriate performance requirements outlined in the BCA. Joins & gaps need to be appropriately fire rated. Eg. vertical control joint will need fire rated sealant & horizontal joins must be blocked with compressible fire rated material.

Fire Certificates & Reports

Copies of the test reports and/or opinions can be obtained by contacting Hebel Technical Services. A certificate of test FSV0356 is provided in Appendix D of this guide. The Hebel PowerPanel System achieves a FRL of 240/180/180.

Internal Fire Source

For an internal fire source the studs must be protected by the internal wall linings. Refer to CSR Gyprock Red Book for specifications.

External Walls in Fire - BCA Provisions

Where necessary, the designer and builder should ensure the structural support framing, its connections as well as the Hebel PowerPanel installation are satisfactory when subjected to fire conditions. The BCA Vol 2 (Part 3.7.1) outlines provisions for external walls for fire resistance in a residential building where the external wall is less than 900mm from an allotment boundary or 1.8m from another building on the same allotment. If this occurs an FRL of not less than 60/60/60 is required from the outside.

Fire Performance of Hebel PowerPanel

The Hebel PowerPanel System was tested at the CSIRO. North Ryde and Fire Resistance Level (FRL) of 240/180/180 was achieved (refer to Appendix D). Note, the fire source was on the PowerPanel side. This excellent result enables Hebel PowerPanel to be used in the following applications:

• Walls on zero line allotment blocks.
• Multi-storey residential dwellings - external walls.
• Commercial developments.
• Infill PowerPanels.

NOTE: In the above applications, each PowerPanel should be screwed as specified in this guide, except a minimum of three screws should be installed through the middle Top Hat into each PowerPanel (refer to the fire test certificate in Appendix D).

Bushfire Areas

The introduction of Australian Standars AS 3959 - 2009 - Construction of buildings in bushfire-prone areas presents new challenges to building designers with differing design requirements across six Bushfire Attack Level (BAL) categories. The PowerPanel System complies with all six BAL requirements and achieves a Fire Resistance Level (FRL) of 240/180/180 - exceeding the standards.

Design Considerations

Fire Stop Penetrations

Penetrations through Hebel PowerPanel to accommodate pipework, electrical cabling or ductwork will have to be protected (fire stop), to precent the spread of fire through the penetration. The penetration can be protected with proprietary products, such as:

• Fire Rated sealants.
• Fire collars and intumescent wrapes. Fire rated mortars.
• Fire rated pillows.
• Fire rated switch boxed.

Hebel recommends contacting the manufacturer to obtain the appropriate product/solution and installation method fro the application and wall configuration.

Energy Efficiency

Building Code of Australia (BCA)

The BCA 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 the Performance Requirements for the efficient use of energy for internal heating and cooling in buildings. The majority of changes have been associated with the Housing Provisions.

The Performance Requirements for energy efficiency ratings are dependent upon the form of construction (i.e. walls or floors), Class of Building, and the type of areas being separated. The performance requirement is a value that is the Total R-Value, which is the cumulative total of the individual R-Value, which is the cumulative total of the individual R-Values of the building system components.

The Hebel PowerPanel System

One of the primary design objectives in planning a building is to provide a cost effective comfortable living/working environment for the building's inhabitants. Exploiting the inherent thermal mass the insulation qualities of Hebel enables the designer to achieve this objective.

Several international comparative studies have been conducted to investigate the benefits of incorporating AAC walls in place of conventional wall systems. 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 excellent performance was the result of the three characteristics - thermal mas, thermal insulation, and the air tightness of the construction.

The level of insulation provided in a wall is determined y the required Total R-Value. The higher the required Total R-Value the greater the insulation provided. Hebel PowerPanel incorporating CSR Bradford insulation can provide the R-Value ratings outlined in Table 2.4

Thermal Insulation

It is recommended that insulation materials be installed to enhance thermal insulation properties and occupant comfort. Insulation also improves the acoustic performance of the wall against outside noise.

The BCA provides Deemed-to-Satisfy Provisions for compliance and installation of the various types of insulation. The insulation should be installed in Hebel PowerPanel such that it forms a continuous barrier to contribute to the thermal barrier. All insulation installed in Hebel PowerPanel must comply with: AS/NZS4859.1; or AS2464.3 for loose fill insulation.

Air Tightness

As outlined in Section 8.1 the thermal performance can be influenced by many factors. Most of these are related to the design decisions and properties of the adopted materials. Construction practices can also significantly affect the performance with poor sealing, resulting in drafts. The tight construction tolerances of AAC provide a wall with low air infiltration rate.Testing at the CSIRO ( Test Report DTM 327) on Hebel blockwork with thin bed adhesive joints has determined an air infiltration rate of 0.3L/s (0.014% of internal volume). For PowerPanels having fewer thin bed adhesive joints, a rate less than this could be achieved.

Sarking

As well as controlling condensation and acting as an air barrier, a sarking can be used to significantly improve the thermal insulation and energy efficiency performance of a building solution. Sarking layers can alter the performance of the cavity by providing a reflection side. The design of the sarking arrangement in complex and should be performed by the appropriate project consultant.

Where the sarking layer provides a weatherproofing function, the sarking material must comply with AS/NZS4200 Parts 1 and 2.

Sound Transmission & Insulation

Overview

Current BCA Sound Transmission and Insulation Requirements

The Hebel PowerPanel System is primarily used in buildings that have a domestic type of activity purpose. The BCA generally classifies these buildings into class 1 or 10. The acoustic performance requirements for external walls in these buildings or their building elements are not currently stated in the BCA. If a building using the Hebel PowerPanel System was required to provide acoustic performance, then the performance level requirements for a building envelope and elements would be set by the relevant authorities (i.e. Local Councils, client specific requirements and etc).

Design Recommendations

Acoustic design is a complex science, and there will the instances where s apecialist acoustic consultant is required.

For walls requiring acoustic performance Hebel recommends:

1. Engaging a reputable acoustic consultant on a project-by-project basis to provide design advice and installation inspections.
2. When selecting the appropriate components for the Hebel PowerPanel System, 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 PowerPanel System, and any required modification of the installatin details pertaining to the systems.
4. Increasing cavity widths, using higher density or thicker insulation or plasterboard, will generally maintain or increase the acoustic performance of the Hebel PowerPanel System.

Coating Requirements

Hebel PowerPanel requires an appropriate external coating system and sealant detailing to ensure a water resistant and vapor permeable building envelope is achieved.

Generally, the external face of Hebel PowerPanel is coated with a high build acrylic levelling and finishing system incorporating a water resistant flexible "elastomeric membrane" top coat, in accordance with the recommendations of the coating manufacturer.

Hebel has worked closely with Delux AcraTex to develop a range of performance warranted coating systems for all Hebel systems.

Performance Requirements

The following are items to be considered when selecting a coating system:

Manufacturer approved:

• Hebel recommends in all cases the preferred use of Dulux AcraTex coatings systems defined within this document.
• NB: Where other manufacturer's coating systems are applied to Hebel external walls these coatings systems must be warranted by the coating manufacturer as appropriate for coating an AAC substrate. As a minimum, alternate manufacturers must verify and warrant coating system confirmance to the properties defined below.

Surface adhesion:

• The substrate preparation and coating application should be in accordance with the coating manufacturer's specification.
• Before applying finishes in coastal areas (refer to definition), all PowerPanels must be thoroughly washed with fresh water to remove any salt residue. Refer to coating manufacturer for additional requirements.

Water resistance:

• The primary objective of the coating system is to prevent ingress through it, yet allow vapor in and out of the AAC substrate.
• Proven water resistance capability: Transission: <10 grams/m²/24hr/1kPa

Water Vapor Permeability:

• For a coating to allow the "escape" of water vapor, the coating must be vapor permeable.
• The coating system should comply with the following performance parameters:

w.sd<=0.2kg/(m².hm^0.5) where,

- Coefficient of Water Absorption w<= 0.5kg/(m².h^0.5)

- Equivalent Air Layer Thickness of Water Vapor Diffusion Sd<= 2m.

Notes:

• A conefficient of water absorption (w<=0.5) means that minimal dampness is absorbed regardless of the time factor.
• A coating with an (sd<=2m) has less resistance to water vapor diffusion (escape) than a static 2m thick air layer.

Compatibility:

• Ensure the coating system is compatible with the substrate and construction system components, ie:

- Coatings may not adhere to silicone or other sealants and mastics.

- Excessive joint adhesive or mortars smears across the panel face may require removal or specific primers.

Durability:

• The coating must be durable and not deteriorate with exposure to light (UV) and weather.

Elasticity:

• The coating must be able to bridge a 1mm minimum crack width.
• The coating manufacturer can specify the minimum design specification (thickness), so that the coating is serviceable and durable.

IMPORTANT: This list of performance requirements indicates that a specific fit-for-purpose coating system must be adopted, and that a simple paint coating would most likely be an inadequate coating system. Variations to the coating system must be approved and warranted by the coating system manufacturer or representative.

Coating

Dulux AcraTex Hebel coatings have been specifically formulated and engineered to match the thermal and hysical characteristics that are unique to Hebel ACC.

Easy to work with, Dulux Acratex Hebel coatings are designed to help you achieve the perfect finish to any Hebel project, including the highly sought after smooth, Monolithic look.

Given the variability of some coatings - not all are what they claim to be - customers can be confident that when they choose Dulux AcraTex Hebel coating systems they have been correctly formulated to a consistent, durable formulation backed by Dulux and Hebel. Hebel does not recommend cement based so called "acrylic prepacked" renders or site mixed cement renders be applied to Hebel PowerPanel.

Dulux AcraTex Hebel coating systems have been formulated with unique acrylic polymer resins incorporating specially graded fillers and selected additives to enhance the application and workability of the mix, ensuring a consistent durable performance finishing system to the Hebel facade.

Dulux AcraTex Hebel coating systems have many advantages over traditional cement based site mixed or prepacked renders and coatings systems:

• Increased flexibility
• Improved adhesion to Hebel substrate
• Matches thermal properties of Hebel substrate
• Faster curing
• Improved crack joint resistance
• Peace of mind - warranted performance

Examples of suitable coating systems over PowerPanel include:

• Dulux AcraTex Hebel PowerBase & PowerFinish
• Dulux AcraTex AcraPatch HighBuild Leveller & Dulux AcraTex Coventry or Tuscany texture coatings with Dulux AcraSkin or AcraShield weatherproofing topcoat
• Dulux AcraTex AcraPatch HighBuild Leveller with Dulux AcraSkin or AcraShield weatherproofing topcoat

Weatherproofing

Sealants

All control joints must be sealed with suitable external polyurethane sealant. All gaps between the PowerPanel panels and framing around windows must be caulked with an appropriate external grade sealant.

The sealant should be installed in accordance with the sealant manufacturer's specifications.

Wall Flashings

In general, flashings shall be designed and installed in accordance with SAA-HB39 1997 - Installation Code for Metal Roofing and Wall Clading.

Wall Wrap

For Hebel PowerPanel, wall wrap is only required for insulation and condensation control as well as a corrosion barrier over CCA treated timber frames. Although not a mandatory requirement, the installation of wall wrap is considered good building practice. Wall wrap must be designed and installed in accordance with AS/NZS4200 Part 1 -Materials, and Part 2 - Installation.

Hebel PowerPanel Installation Sequence

Tools and equipment for construction

The basic tools required to assist in the installation of the PowerPanel System are shown in Figure 3.1. These may be purchased through a Hebel distributor and include:

1. Stirrer - fitted to the electric drill, the stirrer is used to mix the Hebel Mortar, Hebel adhesive and Hebel HighBuild render inside the mixing bucket.
2. Notched Trowel - the notched trowel is used to apply the Hebel Adhesive to the Hebel surfaces. The width of the trowel must match the panel thickness to ensure the adhesive is applied with full and even coverage.
3. Panel Lifters used to carry the panels around the work site.
4. Sand Float - used to remove excess Hebel Adgesive and smooth joints between panels.
5. Levelling Plane- used to even out inconsistencies in the Hebel panels
   • Power drill (clutch driven).
   • Power saw with metal or diamond tipped cutting blades.
   • Dust extraction system.
   • Sockets for screws.
   • Personal Protective Equipment (PPE) such as goggles, ear muffs/plugs and face mask, used when site cutting the PowerPanel panels.

Installation of Services

This installation of services in the building are the same as methods currently being used throughout the industry.

Services should be installed through the frame to avoid intering with Top Hat layout, but if they are to be fixed on the outside of the frame, they should only run horizontally parallel to the Top Hats - typically 300mm up from the bottom plate.

Penetrations through the PowerPanel for services should be neatly filled and joint sealed with an external grade sealant.

Construction Details - Installing Hebel PowerPanel

Single Storey Construction Details

Two Storey Addition

Hebel PowerPanel Fixing & Installation Detail

Footing Junction Details

Wall Junction Details & Sections

Control Joints

The following information provides the necessary rules for Control jointing when installing the Hebel PowerPanel System

• Vertical Control Joints required at maximum 6m centres
• Vertical Control Joints required at external and internal corners
• Vertical Control Joints required above and below all doors, including sliding and garage doors
• Horizontal Control Joints Required at every horizontal floor junction
• Horizontal Control Joints required at a maximum height of 3.9m

For openings <2450mm in width

Control Joint not required. If the straight joint that extends above or below the window jamb is less than 600mm long, a control join or a Glued and Meshed Joint is required.

Note: The minimum Lintel panel height above windows is 270mm

For opening >=2450mm and < 3600mm wide

• Control Joint required to at least one side of the opening (i.e. above and below the opening). If the straight joint that extends above or below the window jamb is less than 600mm long a control joint or a glued and meshed joint is required to the opposite side of the opening. Note: The minimum Lintel panel height above windows is 270mm.

For openings >=3600mm in width

• Control Joint required to both sides of the opening (i.e. above and below the opening). Note: The minimum Lintel panel height above windows is 270mm.

Footing and slab design to comply with AS 2870 (2011)

Door & Window Detail

Miscellaneous Details