2.6 Installing Integra Lightweight Concrete Flooring

Introduction

This specification is limited to New Zealand conditions in particular the wind and earthquake loads as set out by NZS 3604:2011 (Timber Framed Buildings) and AS/NZS1170: 2004 (Structural Design Actions). The Integra Flooring System uses the Integra panels as a flooring material, laid on top of timber floor joists. Integra panels are autoclaved aerated concrete (AAC) panels that are produced in a range of sizes and lengths.

  • Dry Density: 520kg/m3
  • Compressive strength : 4mPa
  • Modulus of Elasticity, E: 1800MPa
  • Substrate Thickness: 75mm Integra panel
  • Size: 600mm wide x 1800mm long
  • Weight: 45.5kg. Thermal Conductivity: 0.174W/(mK)
  • Thermal Resistivity: R:0.56
  • Substrate Thickness: 75mm Integra panel

NZBC Compliance:

The Integra Flooring System is constructed in accordance with the details and specification and will meet the relevant sections of the New Zealand Building Code (NZBC) including:

B1 – Structure.

The Integra Flooring System is constructed in accordance with this specification can support a maximum live load of 3kpa.

F2 – Hazardous Building Materials

The dust from cutting the panel is irritating to the eyes, skin and respiratory system. Inhalation may cause health problems. When cutting, grinding or drilling panels do so in the open space or in well ventilated spaces and wear approved safety glasses and dust mask. All methods of cutting, grinding and drilling must comply with the latest OSH regulations. Provided appropriate safety equipment is used when cutting (eg. Safety Glasses, Hearing protection and Dust Masks are used)  and appropriate precautions are made when handling and lifting then this system will meet the requirements of this section.

Framing Set-out

Resene Construction Systems Integra Flooring Panels shall be laid generally in full panels wherever possible. The panels shall be laid in half stretcher bond. The panels can be readily cut to size to suit floor layout requirements and openings.

Resene Construction Systems Integra Flooring Panels must be supported on either a light timber framed system or a light steel framed system. The light timber framed system may comprise timber joists, ply webbed joists, trussed joists, laminated timber joists, timber and steel beams or any combination of the above. The floor framing system should be designed for the appropriate live load plus the in service mass of the panels.

For framing designed to NZS3604 “Timber Framed Buildings” compensation needs to be made for the extra weight of the flooring panels. Framing sizes should be selected from the appropriate table for a live load of the Design Live Load plus 0.5kPa for the Floor Panel. For example, for normal domestic loading the floor joists should be chosen from the 2.0kPa live load tables (1.5kPa + 0.5kPa). Similarly for normal domestic decks the deck joists should be chosen from the 3.0kPa (2.0kPa + 0.5kPa) live load tables

Floor Loading

Resene Construction Systems Integra Flooring Panels have been designed to support a concentrated live load of 2.7kN applied over a 0.3m x 0.3m area. Concentrated loads from load bearing walls or point loads shall be supported by additional framing such as joists or blocking. The bearing stress in the panels shall be limited to 1.0MPa.

Panel Layout:

Timber floor joists have been sized according to maximum spans for the following spacing: 360mm, 450mm, and 600mm. Integra Floor Panels should be laid as full panels wherever possible. The panels shall be laid in a stretcher bond pattern. Integra Floor Panels can be readily cut to size to suit floor layout requirements and openings. Concentrated loads (eg. Supporting a load bearing wall must have additional blocking or be situated over a double joist).

Bracing Walls

Where a bracing wall occurs on top of the Integra Floor System it shall have either supporting blocking or a joist directly underneath. A Gib® HandiBrac™ can be installed with a Galvanised Coach Screw fastened through the bottom plate into the supporting floor joist/blocking.

For bracing walls parallel with the floor joists the bracing wall shall either be over a joist or be supported by solid blocking. Blocking shall have a minimum width of 45mm.

Penetrations

Provided they are isolated, penetrations up to 80mm in diameter may be made in Integra Floor Panels without reducing the structural performance of the floor system. Larger penetrations or groups of penetrations should be supported by additional blocking. Penetrations should be finished using a collar or appropriate sealant.

Lateral load transfer

Panels are fixed to the floor joists using 14-gauge, 100mm long screws @ maximum 150mm centres around the perimeter of the floor area, and at 300mm centres along all intermediate joists. A minimum edge distance of 50mm is recommended from the short edge to the first screw, although screwing in on an angle is permitted. If on the short edges the panel overhangs a floor joist it must be cut back so that it is supported on this edge.

Wet Areas

Where Integra Floor Panels are being used in a Wet Area, an appropriate waterproof membrane must be installed in accordance with the manufacturer’s specifications. Please check that adhesion to the panels will not be compromised by having a dusty surface, a masonry sealer may be required prior to any membranes being installed.

Floor joist sizes

Table 1 sets out the joist sizes based on spacing of 360mm, 450mm and 600mm joist spacing.

Acoustic performance

The New Zealand Building Code requires an acoustic barrier between two tenancies to have an STC rating of at least 55. In order for a material to have an STC rating of 55 each frequency band between 125Hz and 4000Hz must have a ‘deficiency’ of no more than 8 and the sum of all deficiencies must be no more than 32. For more information regarding the acoustic values of Integra, refer to the report from Marshall Day Acoustics.

Construction joints

Construction control joints should divide the Integra Floor Panels into separate floor diaphragms.

Construction joint locations should be as follows:

  • At changes in panel and joist direction
  • At load bearing bracing walls to ensure that the floor diaphragm is continuous between bracing
  • walls
  • Over support walls or beams
  • At 6.0 m maximum spacing

Components

  • Integra Floor Panels
  • 14g x 100mm Galvanised Integra Screw (for fixing the Integra Floor Panels)
  • 14g x 150mm Galvanised Integra Screw (for fastening bottom plates)
  • Resene Construction Systems AAC Adhesive (for joining Integra Floor Panels)
  • Resene Galvo-Prime – Brush applied waterborne galvanised iron primer or Zinc rich spray pak primer / solvent bourn- exterior solvent borne Spray application (for priming exposed steel)
  • Broad-knife 
  • Power saw with metal or diamond blade
  • Impact Drill or Standard Drill with hex drive drill bit
  • Safety Equipment (Gloves, Earmuffs, Eye-ware, Respiratory Protection)

Installation

Check that sub-floor/joists are straight and true

Measure 600mm in from boundary joists (where the intersecting joists run into) at both ends of the floor. Mark this with a chalk line and continue this process across the floor

Starting from the corner of one of the boundary joists you measured from, lay the first Integra Floor Panel so that it is parallel with that boundary joist. You should make sure that both of the narrower ends of the Integra Floor Panel are supported on joists/blocking. Make sure that the edge with the groove in it, is on the boundary joist edge.

Around all boundary joists the fixing centres must be at a maximum 150mm. Along all intermediate joists and blocking fixing, centres must be at a maximum of 300mm. Where 2 Integra Floor Panels meet on a floor joist/blocking, screws can be fixed by screwing in on an angle from both sides. All full sheets of Integra Floor Panels must be supported by at least 2 intermediate joists

Where cutting of panels lengthwise is required, the minimum width of cut panel allowable is 200 mm to ensure sufficient reinforcing is located in each panel. If a narrower piece is required against a floor edge, the last two panels should be reduced in width so that both exceed 200 mm in width. All reinforcing exposed on cut panels should be coated with anti-corrosion agent.

Continue along the boundary joist installing Integra Floor Panel as above, ensuring they remain parallel with the boundary joist.

Before installing any of the second row of panels you will have to apply Resene Construction Systems AAC Adhesive. The easiest way to do this is to apply Resene Construction Systems AAC Adhesive into the groove of the panel you are about to install using a Broad-knife. Take care not to over-pack the groove then carefully install the  Integra Floor Panel into the tongue of the first row of Integra Floor Panels in stretcher bond. The second row of Integra Floor Panels must be installed in a stretcher bond pattern (refer to Sheet 1 “Flooring layout”). The Integra Floor Panels will have to be cut to allow this to happen. Make sure that all narrow panel ends are supported on joists.

Screw fix the panel a minimum of 150mm from either side of the panel following along the joist. Two screws are required in each panel at each joist. Screws in the end edge of the panel may be skewed to achieve the 50mm end distance requirement, larger screws (125mm) may be required in this area if you are skewing screws at a sharp angle. The screws must be wound into the panel until the head is 2mm – 3mm below the panel surface. Panels must be supported on a minimum of two joists. Screws into joists are driven without drilling of panels and excessive adhesive should be removed immediately. Screw holes are filled with Resene Construction Systems AAC Adhesive and any chips on panel edges should be filled with Resene Construction Systems AAC Adhesive.

All Bottom Plates should be screwed down using a 150mm fasteners at 300mm centres. Panel around the boundary joists must be fastened at 150mm centres, this can be achieved by screwing your panel off at 300mm centres and fastening your perimeter plate between theses fixings to achieve the 150mm centre requirement.

Continue across the entire floor making sure to keep a stretcher bond pattern. Try and keep all panel joins tidy by scraping off any Resene Construction Systems AAC Adhesive so that the joins are flush.

Make sure that all narrow ends of the Integra Floor Panels also have Resene Construction Systems AAC Adhesive applied to it before butting in the adjoining panel.

Once you have completed the flooring go around all the exposed edges of Integra Floor Panels and prime all the exposed steel using an appropriate primer.

Floor Protection

Once the floor has been laid we recommend that the floor panels are protected prior to finished floor coverings and preparation being completed. Thin plywood, or RAM board can be laid on top of the flooring where high traffic is expected during construction (ie. hallways and entrances). This will protect and minimise surface damage to the INTEGRA Floor panels.

Floor Finishings

Where the floor covering specification calls for 'thin section' flooring such as Vinyl and Carpet tiles, also other floor coverings with low surface defect tolerances then the floor will require the application of a Floor Levelling/surface preparation compound prior to installation of these. Carpet with underlay can generally be installed as per a standard concrete floor preparation guidelines.

Carpets

Installation of carpet smooth edge prior to laying carpet requires the use of specifically selected nails (Annular Grooved)  as well as an adhesive.  Use appropriate primer with all adhesives.

Tiles

As per manufacturer’s guidelines.  Apply tiles to screed or adhesive as per normal floor. Screed Floors to maintain fall and/or levelling. Refer to Tile Adhesive manufacturer for Primer suitable for AAC (porous materials) to alleviate suction.

Timber Floors

All timber floors require a vapour barrier to be installed prior to the flooring being installed. We also recommend the use of a Floor Levelling Compound to ensure the floor is flat.

Batten fix  Anchor battens at the required centres using anchors suitable for AAC

Floating Timber Floor Underlay / backing installed as per normal for a concrete slab.

Vinyl (Linoleum)

Floor levelling is generally required: Installed as per manufacturers requirements

Always consult your floor covering specialist for advice.

Recommend Floor Levelling Screeds and Vapour Barriers

The recommend floor levelling compound is Bostik Ul-200. The recommend vapour barrier is Bostik Moisture Seal Epoxy Water Vapour Barrier. For a full specification please contact your local Bostik Representative.

Table 1  – Joist Sizes (NZS3604:2011)

Live Load (kPa) Span (m) 360mm Joist Spacing 450mm Joist Spacing 600mm joist Spacing
1.5 1.2 90 x 35 90 x 35 90 x 35
  1.5 90 x 35 90 x 35 140 x 35
  1.8 140 x 35 140 x 35 140 x 35
  2.1 140 x 35 140 x 35 140 x 35
  2.4 140 x 35 190 x 45 190 x 45
  2.7 190 x 45 190 x 45 190 x 45
  3 190 x 45 190 x 45 190 x 45
  3.3 190 x 45 190 x 45 240 x 45
  3.6 190 x 45 240 x 45 240 x 45
  3.9 240 x 45 240 x 45 240 x 45
  4.2 240 x 45 240 x 45 290 x 45
  4.5 240 x 45 290 x 45 290 x 45
  4.8 290 x 45 290 x 45  
2.0 1.2 90 x 35 90 x 35 90 x 35
  1.5 90 x 35 140 x 35 140 x 35
  1.8 140 x 35 140 x 35 140 x 35
  2.1 140 x 35 140 x 35 190 x 45
  2.4 140 x 35 190 x 45 190 x 45
  2.7 190 x 45 190 x 45 190 x 45
  3 190 x 45 190 x 45 240 x 45
  3.3 190 x 45 240 x 45 240 x 45
  3.6 190 x 45 240 x 45 240 x 45
  3.9 240 x 45 240 x 45 290 x 45
  4.2 240 x 45 290 x 45 290 x 45
  4.5 240 x 45 290 x 45  
  4.8 290 x 45    
3.0 1.2 90 x 35 90 x 35 140 x 35
    1.5 140 x 35 140 x 35 140 x 35
  1.8 140 x 35 140 x 35 190 x 45
  2.1 190 x 45 190 x 45 190 x 45
  2.4 190 x 45 190 x 45 190 x 45
  2.7 190 x 45 190 x 45 240 x 45
  3 190 x 45 240 x 45 240 x 45
  3.3 240 x 45 240 x 45 240 x 45
  3.6 240 x 45 240 x 45 290 x 45
  3.9 290 x 45 290 x 45 290 x 45
  4.2 290 x 45 290 x 45  
  4.5 290 x 45    
  4.8