Hebel Panel

12.1 Building Setout

Hebel PowerWall 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 sitecutting of PowerPanels, which is time consuming and wasteful, as compared to the installation of stock PowerPanels.

Vertical Dimensions

A few important criteria affect the vertical setout of the building:

1. A stepdown from the main slab is required for Hebel PowerPanel installation. The stepdown should be greater than 20mm deep and a maximum of 95mm wide. The actual depth of the stepdown is dependent on the height of the eaves above the slab level, and is rarely greater than 150mm. The following quick check can be used to confirm the stepdown dimensions.

2. For all Hebel PowerPanel installation the bottom of the PowerPanel must remain 75mm above the finished ground level (FGL). This minimum distance satisfies recommendations of the current termite guidelines (refer to BCA Vol. 2, 3.1.3. and AS 3660.1). The builder should ensure that this requirement is clearly communicated to the future home owner.

3. The top of the PowerPanel should extend 50mm above the eaves to prevent any water running down between the PowerPanel and the stud frame. Attention should be given to the draining of the eaves.

4. The vertical setout and vertical dimension of the windows and other openings is not critical for Hebel PowerWall construction, as all the PowerPanels are sitecut to accommodate this setout. However, if windows are installed in the garage, they must be located up to the underside of the eaves if there are PowerPanels above (ie. in a gable wall).

5. When 2.7m or 3.0m long PowerPanels are used, a PowerPanel can be installed horizontally over the openings, with their length and width sitecut to suit. No galvanised steel angle lintel or additional top hat is required if no other PowerPanels are seated directly on top of this horizontal PowerPanel. In gables, a steel angle is required on top of the horizontal PowerPanel or additional top hats to the PowerPanels over, to carry the weight of the gable PowerPanels above. Refer to Detail 17.6.4 for further information.

6. As a guide, Table 11.1 gives the appropriate PowerPanel lengths for a variety of possible building configurations.

Fig. 12.1  Typical Stepdown Detail

Fig. 12.2  Typical Eaves Detail

Fig. 12.3 Typical Window Head Detail

Table 12.1  Panel Lengths

 Horizontal Dimensions

The horizontal setout of the building is vital, as incorrect drawings lead to problems with the frame and hence the PowerPanel installation. Please note the following items which require careful consideration during the building design stage.

1. Setting the building out to a 300mm or 600mm module is most important. All openings should be clearly dimensioned on the plan, as well as the exact size of the opening. Although site tolerances can be made up during the installation process, it is important to achieve an efficient layout on the drawing board first.

2. Setting up a grid across the plan will not help to achieve the required layout, as the orientation of the PowerPanels in each corner affects the setout. There are no rules to setting out a corner ; however, be aware that a 10mm control joint is normally required at every corner. Therefore an 85mm offset occurs along one side (refer to Detail 17.9.1). You may choose to set a standard corner orientation. For example, joints will occur only in the side walls, and hence the offset will occur on these walls.

3.The location of all control joints should be noted on the drawing and a 10mm gap allowed in the dimensioning of the building. Refer to Section 11.4 for guidelines on the location of control joints around a building.

Fig. 12.4  Typical Modular Layout of Window

Fig. 12.5  Typical Corner Detail

Fig. 12.6  Typical Control Joint Detail

4. To assist in maintaining the modular setout of the building, windows should be ordered to suit the 300mm module. However, if the length of PowerPanel required below the sill is less than 600mm, then a site cut horizontal PowerPanel (rather than vertical PowerPanels) can be installed here and hence the width of the window is not critical. Typically, external doors and sliding doors are full height and hence their width is not critical to the module, as there are no PowerPanels required above or below, but it should be noted on the drawing. While most standard window sizes do not exactly fit the 300mm module, often being 10mm greater in size, this is easily incorporated into the construction (refer to Detail 17.8.1). Additionally, a number of manufacturers are prepared to supply the windows to the desired width with volume orders.

5.The distance between openings should not be less than 300mm, obviously to suit a standard PowerPanel. With regard to splays and bay windows, the same principle applies. Note that for 45° splays, a 600mm wide PowerPanel can be site-cut to a minimum width of 270mm.

Fig.12.8 Panels Below Window Detail

Fig.12.9  Typical Bay Window Detail

12.2 Termites

It is the builder’s responsibility to ensure that all council and Australian code requirements are fully adhered to in regard to the design of the house for preventing 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 PowerWall is ideally suited to the exposed edge method of perimeter protection. BCA 2006 Vol. 2 Part 3.1.3 deals with termite risk management and the reference code is AS3660.

 12.3 Footings

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

12.4 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 (lateral 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. There are two categories of joints:

• Articulation Joints (A.J.) are provided to relieve induced stresses due to support structure movement. The joints make the walls more flexible by breaking the wall into a series of small PowerPanels. Differential movement between the facade and adjacent structural elements need to be accommodated with articulation joints.
• Control Joints (C.J.), (one type is an expansion joint), are provided to relieve the induced stresses resulting from thermal expansion or contraction of the AAC, or differential movement between the AAC and another material or structure, such as abutting walls or columns of concrete or brickwork. Control joints can delineate coating shrinkage breaks.
• A joint may perform the function of either an articulation joint or control joint or both.

   

IMPORTANT

There are restrictions provided to the maximum length of wall:

Small service penetrations through the PowerPanel of PowerWall 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

Further to the discussion on window sizes in Section 11.1 (B) (iv) the builder should also ensure that the reveal size is correct to suit PowerWall. Refer to the table below for recommendations: The sizes above typically apply to aluminium framed windows. If timber windows are being used similar tolerances and guidelines apply. Refer to Section 17.8 for a section through the sill of a timber window.