- These notes and details are to be read in conjunction with the project’s contract documentation.
- All materials and workmanship shall be in accordance with this Installation Guide, the current edition of the Hebel Technical Manual and other Hebel documentation.
- Refer to architectural drawings for all setting out dimensions.
- Do not scale drawings, use written dimensions.
- Should any omission, penetration, cutting of panels, discrepancy or fault exist, contact the designer immediately for a decision before proceeding with work.
- All load-bearing walls, bearing on Hebel floor panels, shall be supported separately in accordance with the project engineer’s design.
- Hebel accepts no responsibility for the design or selection of supporting walls, lintels, beams, columns or other structural members.
- Corrosion protection of all structural steelworks shall be specified by the project engineer or architect.
- The temporary restraint of walls is the responsibility of the builder or installer.
- PowerBlocks on site should be protected against rain and water saturation. This can best be achieved by leaving the shrink-wrap cap on the top of pallets and covering the top of blockwork if rain threatens. PowerBlocks should not be laid in the rain.
11. Ensure engineering tie-down rods are present and located in accordance with the engineer’s documentation.
12. Ensure control joint locations are marked out in accordance with the engineering documentation.
Fig 9.1: Wall Construction Diagram
Table 9.1 details Hebel recommendations for Coating System options for Low Rise and Detached Residential construction to deliver a durable, monolithic appearance.
Hebel and Dulux Acratex have developed coating systems designed specifically for the Hebel AAC substrate and warrant these systems for 7 years. Performance requirements for alternate system options are provided. In such circumstances, the project specifier must satisfy themselves that systems are engineered and suitable for relevant project requirements.
General purpose, site or pre-bagged sand and cement renders must not be used on Hebel PowerBlock walls, owing to potential variability and unsuitability of formulation for Autoclaved Aerated Concrete (AAC).
Conventional exterior low build paint systems must not be used, as their ability to accommodate normal expansion and contraction in order to maintain a crack free protective layer is not assured.
Refer to “High Performance Coating Systems” brochure on the website, for more information.
Reinforcing Mesh Installation
Fully meshing all rendered Hebel surfaces using alkali-resistant glassfibre mesh is recommended to assist in maintaining render integrity and minimising consequential cracking. The minimum requirement is to mesh at corners of wall openings (doors and windows) to minimise corner cracking. The mesh should be embedded into the wet first pass of Hebel HighBuild.
Plasterboard can be direct fixed to internal Hebel PowerBlock walls. It is recommended that battens be used behind plasterboard linings on the inside surface of external walls. Fibre Cement sheet linings must be installed on battens.
Table 9.1 Coating systems for Hebel PowerBlock
of Hebel HighBuild
to a project
PowerBlock Laying Procedure
1. First Course
- Mix Hebel Mortar according to the directions on the bag.
- Mix Hebel Adhesive according to the directions on the bag.
- Lay a DPC (damp proof course) slip joint membrane at the base of all external and internal walls to allow for differential movement between the blocks and the slab/ footing. Cut the DPC around tie rods as required. The DPC must be installed on the slab/footing prior to the application of Hebel Mortar.
- Lay Hebel Mortar to get first course level and plumb. Accurately position a block and tap into place with a rubber mallet. Ensure that the block is level in all places.
- All loose particles and dust must be brushed from the base and vertical end surfaces of all first course blocks before bedding in Hebel Mortar and applying Hebel Adhesive.
- Apply Hebel Adhesive to the perpend of the base blocks using a Hebel notched trowel that matches the block thickness. Ensure full width coverage with 2-3mm final joint thickness.
- Position the next block vertically adjacent the first block. Place the block down into position and gently tap the block end horizontally with a rubber mallet to fully close the vertical joint.
- Tap the block vertically into the base mortar and level with the first block.
- Repeat until the first course is complete.
- Bore holes in blocks for tie-down rods using a 40-50mm auger bit and place over rods where required. Rod must be central in hole.
2. Second and Subsequent Courses
- All loose particles and dust must be brushed from the top of the first course before applying Hebel Adhesive.
- Apply Hebel Adhesive to the horizontal surface using a Hebel notched trowel that matches the block thickness.
- Overlap the block joints a minimum of 100mm over joints in the previous course. Normal practice is to overlap by thickness of the intersecting wall.
- Install wall ties where required, locating centrally accross block thickness and bed into the Hebel Adhesive.
- Position the first block in the second course and gently tap accurately into place with a rubber mallet. Joints must be 2-3mm thick.
- Apply Hebel Adhesive to the perpend of the first block. Position the next block vertically adjacent the first block. Place the block down into position and tap the end with the rubber mallet to fully close the perpend joint. Joints must be 2-3mm thick.
- Tap the top of the block until level with the previous blocks laid.
- Repeat for subsequent blocks.
- Excess adhesive should be cleaned off the block face at the end of each course within 1-2 hours.
- Large holes can be patched using Hebel Patch in accordance with the directions on the bag.
- Bore holes in blocks for tie-down rods using a 40-50mm auger bit, and place over rods where required. Rod must be central in hole.
- Where required construct a bond beam in the top course of loadbearing walls. Minimum dimension is 100mm wide x 200mm high. Use minimum 50mm thick blocks each side to form up bond beam. Reinforcement to be minimum 2x N12 deformed bars. Refer to Floor Panel Note 2 for grout specification.
- Where required construct a ring beam in the top course of the non-loadbearing walls. Cut/rout 60mm x 60mm recess and place 1x N12 deformed bar centrally. Refer to Floor Panel Note 2 for grout specification.
- Ensure that all perpends are completely filled with Hebel Adhesive.
- Ensure holes and chips are completely filled with Hebel Patch. Sand back level.
- Clean off any remaining Hebel Adhesive runs.
- The blocks can be sanded when dry to ensure a good surface is presented for surface coatings.
4. Base Rendering and Sealants
- Mix up Hebel HighBuild render in accordance with the instructions on the bag.
- Apply alkali- resistant glass fibremesh at corners of wall openings (doors and windows) to minimize corner cracking. The mesh should be embedded into the wet first pass of Hebel HighBuild.
- Hebel HighBuild should be applied with a hark and trowel with minimal thickness of 6mm. General purpose, site or prebagged sand and cement renders must not be used on Hebel Autoclaved Aerated Concrete.
- Render must be stopped at control joints to allow the joint to open/close and function correctly.
- All control joints and gaps between blockwork and framing around windows must be caulked with an appropriate flexible sealant.
- Install backing rods approx 10mm from surface.
- Apply primer to the surfaces
- Installed sealants to manufacturer’s specifications.
5. Coatings for External Walls
- Coatings must comprise a high build acrylic texture coat and finish elastomeric paint membrane.
- Conventional exterior low build paint must not be used.
- Allow Hebel HighBuild to fully cure (approx 24 hours depending on weather conditions).
- Apply primer to the Hebel HighBuild.
- Apply texture body coat such as Dulux AcraTex. Ensure texture coat stops at control joints.
- Apply finishing sealants in control joints.
- Apply first finishing paint elastomeric paint membrane.
- Apply second coat of elastomeric paint membrane as required.
- Refer to manfuacturer’s guidline for coating on AAC PowerBlock work and Hebel HighBuild.
6. Internal Linings
- Plasterboard can be direct fixed to internal Hebel PowerBlock walls.
- It is recommended that battens be used behind plasterboard linings on the inside surface of external Hebel PowerBlock walls.
- Fibre cement sheet linings can not be direct fixed to Hebel PowerBlocks. Installed fibre cement sheets linings on battens.
- Hebel HighBuild render may be directly applied to internal block walls as per pervious instructions.
Floor Panel Notes
- The ring anchor reinforcement shall be a minimum of N12 grade in accordance with AS1302, unless noted otherwise by the project engineer.
- Hebel Mortar should be used as grout for the ring anchor system. A nominal composition of 1 Cement: 4 Sand (5mm maximum coarse aggregate) can also be used. Minimum compression strength of f’cg= 15MPa at 28 days.
- Additives to reduce the grout shrinkage shall only be used in accordance with the manufacturer’s instructions.
- The installer shall support (chair) reinforcement to enable grout to fully surround the reinforcement. Reinforcement shall not be in contact with the panel when grout is placed.
- Grout shall be rodded to ensure complete filling of notch and groove.
- The installer shall provide notch and groove at panel joints as per Hebel standard detail 5.3.5 on page 7.60 in the Hebel Technical Manual..
- Ensure notch is cleared of all loose material and reinforcement cleaned of all foreign material.
- Lightly pre-wet notch prior to pouring the grout.
- Panels shall only be cut on-site as indicated on the engineer’s drawings, otherwise contact your distributor or sales representative.
- Propping of panels may be required to accommodate minor misalignments until 3 days after ring anchor grout is poured.
- All propping shall be removed from Hebel Floor Panels before any walls are erected over.
- Traffic on floor panels is to be avoided for a period of 3 days after the ring anchor grout is poured.
- All panel dimensions are the responsibility of Hebel’s client and are subject to approval by the client before commencing manufacture of panels.