2.0 Benefits

The many benefits of using Hebel PowerBlocks include:

Solid and strong: Hebel PowerBlocks are made from Autoclaved Aerated Concrete (AAC), a strong, solid masonry building material with the advantage of being 25% the weight of conventional concrete.

Acoustic Performance: Significantly reduced sound transmission from room-to-room.

Thermal Resistance: Unique thermal properties result in a more stable inside temperature, reducing the energy required to heat and cool your home, thereby reducing energy bills.

Environmentally friendly: 73% less embodied energy and 61% less greenhouse gas emissions than comparative masonry products*.
*Source: LCA Report GECA 2006

Fire Protection: Non-combustible blocks with frameless construction deliver superior fire resistance. Hebel PowerBlock systems also allow you to build right up to your boundary line.

Pest resistance: Not a food source for termites or vermin and no cavity construction eliminates the chance of harbouring pests.

Design Freedom: Hebel PowerBlock Wall Systems provide absolute freedom to design and build your ultimate dream home – without compromise.

Technical Support: Competent technical support through Hebel distributors.

Energy Efficiency

The unique combination of thermal resistance and thermal mass make building with Hebel a smart choice for meeting Australia’s stringent building regulations.

The thermal performance of a building depends on a number of factors such as orientation and size and aspect of windows. The R-Value of walls and floors can significantly affect the energy-rating outcome of dwellings. A 250mm Hebel PowerBlock has 3 times the R-Value of a cavity brick wall (BCA Vol. 2 Figure 3.12.1.3). The use of Hebel in walls and floors will provide increased thermal performance that can allow more flexibility with other design aspects of a building.

The thermal efficiency of Hebel systems will also reduce the reliance on heating and cooling appliances. The combined effects of running a heater less in winter and fans or air conditioning less in summer can have a big impact on energy costs and the environment.

Single Skin Construction

The AAC masonry constructed from Hebel PowerBlock products is called “Plain Masonry” and the blocks are masonry units referred to as a “Solid Unit”. The type of solid unit is “Autoclaved aerated concrete masonry unit” complying with AS/NZS 4455 – Masonry Units and Segment Pavers.

The larger face dimension and being a single skin, Hebel PowerBlock walls are erected quickly when compared to double brick construction.

Image 2.1:  Hebel PowerBlock home

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3.0 Energy Efficiency

Table 3.1 shows a number of different external wall configurations and identifies which satisfy the BCA requirement for Climate Zones 1 to 8. Table 3.2 lists the component R-Values used as a basis for Table 3.1. For more information on Hebel and energy efficiency refer to Section 3 and Appendix C and D of the Hebel Technical Manual.

Table 3.1:  BCA Energy Efficiency Compliance

Wall Configuration Satisfies BCA Requirements
Climate Zone: 1* 2* 3* 4 5 6 7 8
Class 1 & Class 10a Minimum R-Value: 1.4 1.4 1.4 2.2 1.9 2.2 2.4 3.3
1. 250mm Block Only Y Y Y N Y N N N
2. 250mm Block + 25mm Cavity Y Y Y Y Y Y N N
3. 250mm Block + 25mm Cavity + Sarking Y Y Y Y Y Y Y N
4. 250mm Block + 25mm Cavity + 75mm
PowerPanel
Y Y Y Y Y Y Y N
5. 250mm Block + 40mm Cavity + R1.0
Insulation
Y Y Y Y Y Y Y N
6. 250mm Block + 25mm Cavity + Double
Sided RFL + 25mm Cavity
Y Y Y Y Y Y Y Y
7. 250mm Block + 90mm Cavity + R2.0
Insulation
Y Y Y Y Y Y Y Y

 Table 3.2:  Wall Element R-Value

System Number Construction Overall Thickness R-Value Rw Rw+ Ctr
401 8mm Render in Texture Coat and Paint
250mm Hebel PowerBlock
10mm Gyprock
268 mm 2.1 48 43
402 8mm Render in Texture Coat and Paint
250mm Hebel PowerBlock
28mm furring channels @600mm centres
10mm Gyprock
296mm 2.3 51 43
403 8mm Render in Texture Coat and Paint
250mm Hebel PowerBlock
28mm furring channels @600mm centres
Non reflective (normal sarking)
10mm Gyprock
296mm 2.3 51 43
404 8mm Render in Texture Coat and Paint
250mm Hebel PowerBlock
28mm furring channels @600mm centres
Reflective foil
10mm Gyprock
296mm 2.6 51 43
405 8mm Render in Texture Coat and Paint
250mm Hebel PowerBlock
28mm furring channels @600mm centres with 50mm 11kg – Bradford Glasswool
Non reflective (sarking)
10mm Gyprock
296mm 3.1 53 44
406 8mm Render in Texture Coat and Paint
250mm Hebel PowerBlock
8mm Render in Texture Coat and Paint
216mm 2.1 48 43

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4.0 Fire

Hebel AAC has a BCA Group Number 1. Hebel PowerBlock walls satisfy BCA2008 Vol.2 Clause 3.7.1.5 (a) (iii) masonry construction and therefore suitable for boundary wall construction on a Class 1 building.

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15.0 Construction Details – Tie-down PowerBlock

Required only if specified by design /project engineer

Fig 15.1:  Strip Footing, Double Brick Sub-Floor

Fig 15.2:  Strip Footing, Concrete PowerBlock Sub-Floor

Tie down rods/engineering restraints must be embedded into the footing and pass up through the sub floor and into the Hebel PowerBlock work.

Table 15.1 Top-Plate & Hold-Down selection

Wind Classification Top Plate & Hold-Down
Tile Roof Sheet Roof
N1 A / B / C B / C
N2 A / B / C D / F
N3 D / F D / F
N4 D / F D / F
N5 E / G E / G
N6 E / G E / G
C1 D / F D / F
C2 E / G E / G
C3 E / G E / G
C4 G G
Legend
A 90×45 F7 timber top plate / 700mm deep strap @ 1200mm ctrs.
B 90×45 F17 timber top plate / 1700mm deep strap @ 2400mm ctrs.
C 90×45 F17 timber top plate / Ф12mm rod @ 2400mm ctrs
D 90×45 F17 timber top plate / Ф12mm rod @ 1200mm ctrs.
E 90×45 F17 timber top plate / Ф12mm rod @ 900mm ctrs.
F 100x50x3.0 RHS top plate / Ф12mm rod @ 2400mm ctrs.
G 100x50x3.0 RHS top plate / Ф12mm rod @ 1200mm ctrs.

Fig 15.3 Hold Down Detail for Reinforced Bracing Walls

Table 15.2 provides ultimate racking capacities of reinforced 150mm and 250mm Hebel PowerBlock walls. The reinforcement is N12 bar or 12mm threaded rod at nominal 1000mm centres. The reinforcement must be tied to the footings and wall top plate through the bond beam. Walls resisting racking forces should be evenly distributed within a house and spaced at a maximum of 8.0m. Ceiling and floor diaphragms must be adequately tied to walls to ensure transfer of forces through to the footings. For more information about bracing, refer to Section 6.11 of the Hebel Technical Manual.

Fig 15.4 Roof Top to Plate Fixing to Hebel Wall – Strap (elevation)

Top Plate Hold-Down

Two tie-down methods are provided in this design guide.

1. Strap – 30×0.8mm cut into inside face of external wall min. 700mm deep.

2. 12mm threaded rod continuous from footing through bond beam to top plate.

Fig 15.5 Roof Top Plate Fixing to Hebel Wall-Tie-Down Rod (elevation) Three top plates options are provided in this design guide:

1. 90×45 F7 timber 2. 90×45 F17 timber 3. 100x50x3.0 RHS

The type of hold-down method and spacing depends on the top plate, roof type/span, and wind classification. Refer to Table 15.1 for specifications. For high wind areas, the bracing design is likely to require tie-down rods which will drive that as the hold-down method.

Table  15.2 Reinforced Wall – N12 Bars at Nom. 1000mm CTRS

Wall
Length
(mm)
Min. No. of
N12 Bars
Ultimate Racking Capacity (kN)
150mm PowerBlock 250mm PowerBlock
900 2 5 6
1200 2 8 8
1800 3 16 18
2400 3 24 25
3000 4 36 38
3600 5 45 46
4800 6 54 56
6000 7 63 66

Base of Wall

Fig 15.6 Hebel PowerBlock work on Stiffened Raft Slab Edge Foundation (elevation)

 

Fig 15.7  Concrete PowerBlock Sub-Floor Detail (elevation)

 

Fig 15.8  Double Brick Sub-Floor Detail (elevation)

 

Fig 15.9 Ring Beam Internal Non-Loadbearing Wall (elevation) (No tie down – as specified by design engineer)

 

Top of Wall

Fig 15.10 Roof Top Plate Fixing to Hebel Wall – Tie-Down Rod ( elevation)

 

Fig 15.11 Internal Hebel Load Bearing Wall and Timber Floor Frame Junction (elevation)

Wall Junctions

Fig 15.12  External Wall and Internal Partition Wall Junction  (plan)

 

Fig 15.13  External Corner with Control Joint (plan)

 

Control Joints

Fig 15.14 Control Joint detail (elevation)

Fig 15.15 Typical Bond Beam Control Joint – elevation (Location where no tie down required – as specified by engineer)

 

Fig 15.16 Typical Ring Beam Control Joint – elevation (Location where no tie down required – as specified by engineer)

 

Fig 15.17 Typical Control Joint – plan

 

Fig 15.18 Hebel PowerBlock work Typical Movement Joint Detail (elevation)

 

Fig 15.19 Hebel PowerBlock work Typical Movement Joint Detail (plan)

 

Fig 15.20 Built-in Column Detail (plan)

 

Fig 15.21 Built-in Column Detail (elevation)

PLEASE NOTE:
For all other design details (eg. door, window, floor panels) please follow the previous construction details in Section 14.0)

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