ECOply Corrugated Steel Roof System
A 15 mm tongue and grooved ECOply is placed directly over the rafter or trusses with the face veneer perpendicular to rafter direction.
The butt end joints must be supported. They should be made over the rafter edges or where free ends are unavoidable over a nogging running between the rafters not less than 70 mm x 35 mm set flush to the top of the rafter can be used. Each panel must be continuous over more than one span. Readily available ECOply stress grades are F11 or F14.
Fixing of the ECOply to the rafters is the same as
for fixing of ECOply flooring as detailed in AS 1684
Residential Timber Framed Construction Standards.
The fixing requirements are repeated below.
Nails and screws shall be spaced at 150 mm centres
at panel ends and at 300 mm centres at intermediate
rafters and noggings. ECOply should not be fixed less
than 10 mm from edges.
| Hand driven nails |
2.8 mm minimum diameter, flathead or bullet head nail of a minimum length of 40 mm (2.5 times ECOply thickness) |
|---|---|
| Gun driven nails |
2.5 mm minimum diameter gun nail of a minimum length of 40 mm (2.5 times ECOply thickness) |
| Screws to timber rafters | No. 8 x 30 self drilled countersunk wood screw |
Insulation
The void between the ECOply deck and the underside of the metal sheet is to be filled with 75 mm Anticon glass wool blanket.
At the interface of the metal roof sheet and the fascia, an oversized Fibretex 650 Rockwool strip is to be used to seal between the ECOply and the roof sheet. The Rockwool is to be a minimum of 75 mm wide by 90 mm long and placed on edge. The Anticon glass wool should also be compressed with the Rockwool.
At the ridge and hips a 90 mm wide strip of Fibretex 650 Rockwool is to be compressed to 50% of its size under the ridge cap.
Roof Sheet
A 0.42 mm corrugated roof sheet that complies with AS 1445 can be used. The roof sheet is to be fixed in accordance to normal practices except that double fixings are to be applied along the leading edge of the roof into the Z flashing.
Battens
Either timber or metal battens can be used. Batten depth should not be less than 40 mm and the batten fixed with consideration of the relevant tie-down required for the location.
Further information can be found in Building with tile roofs in bushfire prone areas – A guide for builders and roof tilers, Roof Tile Association of Australia – www.rooftile.com.au
July 2010 (2)
