Non-Cedar Species - Fixing Guidelines

All data reflects standard industry guidelines - type and number of fixings nominated refers to bullet head nails unless nominated otherwise.

Fixings (nails or screws) for weather exposed applications should be non-ferrous (silicon bronze, stainless steel) or if steel, should be HOT DIP Galvanised.

The fixing specifications referred to below should be regarded as minimum. Greater fixing restraints may be required due to weather exposure and aspects of maintenance as covered in the Fixing Criteria and Fixing Options.

Weather Protected Applications - Hand or Gun Nailing

Internal Wall Panelling & Weather Protected External Cladding

Profile Size Max Span Fixing Face Fixed Concealed
70 & 80 x 12 600 40 x 1.6 1 fixing 1 fixing
120 & 130 x 12 600 40 x 1.6 * 1             1         
70 x 18 900 50 x 1.8 1           1         
120 x 18 900 50 x 1.8 *  1              1         
Decor Sections 900 50 x 1.8 1          1         

* face fixed - 120 & 130mm wide profiles may look better with both primary & secondary fixings
see sketch below for more detail on primary and secondary fixing.

Ceiling & Soffit Lining

              Ceiling or Soffit fixed on top of Exposed Rafters or Purlins
Profile Size Max Span Fixing Face Fixed Concealed
70 & 80 x 12 600 40 x 1.6 1 fixing n/a
120 & 130 x 12 600 40 x 1.6 2         n/a
70 x 18 900 50 x 1.8 1          n/a
120 x 18 900 50 x 1.8 2         n/a
              Ceiling or Soffit fixed to Underside of Rafters or Purlins
Profile Size Max Span Fixing Face Fixed Concealed
70 & 80 x 12 450 40 x 1.6 1 fixing 1 fixing
120 & 130 x 12 450 40 x 1.6 * 1            1         
70 x 18 600 50 x 1.8 1          1         
120 x 18 600 50 x 1.8 * 1            1         
Decor Sections 600 50 x 1.8    1             1         

* face fixed - 120 & 130mm wide profiles may look better with both primary & secondary fixings
see sketch below for more detail on primary and secondary fixing.  

Fixing sizes quoted relate to softwood framing - heavier gauges may be necessary for more dense supports.

For internal and weather protected external applications, bright steel bullet head nails are acceptable.
For sea coast environments, specifiers should consider the additional protection provided by hot dip galvanising.

Weather Exposed Applications - Hand Nailing and Screw Fixing

Weather Exposed External Cladding

Profile Size Max Span Fixing Face Fixed Concealed
70 x 12 600 50 x 2.8 1 fixing 1 fixing
120 x 12 600 50 x 2.8   * 1               1         
70 x 18 600 50 x 2.8 1           1         
120 x 18 600 50 x 2.8   * 1               1         
Decor Sections 600 50 x 2.8 1           1         


* face fixed - 120 mm wide profiles may look better with both primary & secondary fixings
see sketch below for more detail on primary and secondary fixing.

Where Screw Fixings are preferred, screws should be of countersunk profile
and be a minimum of same length and same diameter as the nail sizes stipulated above.

Detail in the Table above reflects good building practice which has proven over time to provide a reliable fixing specification for the majority of 'hand fixed' timber cladding applications.
Where a 'gun fixed' or 
engineered fixing specification is considered necessary (particularly in high wind applications), the Table below nominates alternate options which are engineer certified.
  

Weather Exposed Applications - Gun Nailing

Weather Exposed External Cladding

Except where specifically noted otherwise, the following nail fixing data is applicable to all softwood (pine) framing with a joint rating of JD5 or better and all hardwood and cypress wall framing.

The fixing references account for both nail withdrawal and head ‘pull through’.

The fixing references only apply where the cladding is fixed direct to wall frames forming an enclosed wall cavity sealed with internal lining. For other wall systems refer to a registered professional engineer.

The nail sizes indicated in the Table below are commonly available hot dipped or mechanically galvanised coil gun nails, as follows:-          

      A = one 45 x 2.5 galvanised flat head (plain or ring shank, head dia. approximately 5.5mm) - one per board for either
             Face Fixing OR Concealed Fixing.

      B = one 50 x 2.5 galvanised flat head (plain or ring shank, head dia. approximately 5.5mm) - one per board for either             Face Fixing OR Concealed Fixing.

      C = two 50 x 2.5 galvanised flat head (plain or ring shank, head dia. approximately 5.5mm) - two face fixed

 

Non - Cyclonic Regions

Wind
Class'n
General Wall Area
Studs at
Within 1200 mm of Corners
Studs at
  300 450 600 300 450 600

70 mm Cover Widths x 12 mm & 18 mm

N1 / N2 A A A A A A
N3 A A A A A A
N4 A A A A A A

120 mm Cover Widths x 12 mm & 18 mm

N1 / N2 A A A A A A
N3 A A A A A A
N4 A A A A B B (1)

Cyclonic Regions

Wind
Class'n
General Wall Area
Studs at
Within 1200 mm of Corners
Studs at
  300 450 600 300 450 600

70 mm Cover Widths x 12 mm & 18 mm

C1 A A A A A A
C2 A A A A A A
C3 A A A A A B (1)

120 mm Cover Widths x 12 mm & 18 mm

C1 A A A A A A
C2 A A A A B B (1)
C3 A A B B B (1) C (1)

NOTE :-

  1. Minimum Softwood Joint Group JD4
     

Primary and Secondary Fixings with Face Fixing
The sketch below is included here specifically to illustrate the difference between
a 'Primary Fixing' and a 'Secondary Fixing'.
For more detail on both Face Fixing AND Concealed Fixing and the benefits of each, see Fixing Options.

 



 

 

Fixing through the face of cladding and incorporating a nail or screw with a flat or distinctive head - where the head of the fixing is visible and forms an integral part of the character of the installation.

For 100mm nominal boards, the primary fixing may be sufficient. 

For 150 mm nominal boards, the primary and secondary fixing positioned and spaced to a specific pattern may provide a better overall appearance. 

 

 

 

 

 

The fixings used on all weather exposed surfaces should be a minimum of hot dip galvanised steel. If bullet head nails are used for face fixing, the resultant nail hole generally requires filling. An alternative to this is to use a fixing with a different head pattern and allow the head to remain proud of the cladding face.

By far, the best options in this category are from the manufacturers of non-ferrous fastenings - deformed shank silicon bronze nails and stainless steel screws.

For silicon bronze nails, similar nail lengths apply but gauge may need increasing when fixing into higher density framing timbers.
 

For face fixing any cladding, the Spax Pacific Decking Screw provides probably the ultimate solution.The outer section of the dual thread device provides the holding required within the cladding thickness allowing incorporation of a much smaller diameter head.

 

Can we be of further assistance?   Contact our experienced staff