If you’re laying tiles you’ll probably need to lay sarking or underlay on the roof with the reflective side facing down before you attach your battens.
There is a wide range of insulation blankets and reflective type sarking available for metal roofing.
Your choice here will depend on your roof design and choice of roofing materials as well as what you’re trying to achieve.
For example if you have a roof cavity where you can install thermal insulation then your main focus for using foil backed blanket type products will be to reduce condensation and create a vapour barrier under the roof.
Specific tie-downs may be required for attaching battens to support structures in high wind areas.
Fixing timber battens to timber supports:
When joins are necessary in timber battens ensure that the join meets over a rafter or truss. Plan your batten layout so that joined battens are staggered across the roof.
Use the appropriate fasteners. This is extremely important because using the wrong fasteners may lead to roof failure.
For example it might appear that using 75mm nails to attach a 35mm batten to a rafter would be sufficient.
But according to the table in AS 1684.2-2010 this is insufficient for battens at 900mm centres in a N1 wind speed area.
Avoid any contact between CCA treated timber and steel roofing as this can lead to discolouration and may void the warranty.
Fixing steel battens to timber supports:
A 12 x 40mm timber fixing screw through each flange is the minimum fixing size for fixing steel battens to timber.
Fixing steel battens to steel supports:
M5.5 x 40mm batten zips are usually the minimum fixing size for attaching steel roofing battens to steel beams and supports.
When attaching metal roof battens to the supports pairs of screws should be in line with each other and the supporting rafter.
Most steel battens have a convenient groove on the bottom flange to make inserting screws a simple non-slip process.
It’s important that you avoid contact between metal roof battens and copper.
Copper may be present in hot water overflow piping or downpipes and even the water flowing from this copper could cause serious corrosion issues for your metal roof battens or roof cladding.
Other metals and materials may be incompatible also so keep this in mind when choosing your battens.
And you can always call on the helpful experts at No.1 Roofing and Building Supplies when you need some reliable advice.