Association of Hydraulic Services Consultants Australia – Research Foundation 
Page 4 of 10 
3. Results 
3.1 DeltaOrb DPP1110 - 17.5 mm Ribs 1000mm Cover 
DeltaOrb roof sheeting (Figure 1) is classified as closely spaced sheeting ribs with depths 
less than 20mm in Table 3.1 (AS1562.1). Therefore, the minimum allowable pitch for this roof 
profile is 5.0º. Maximum roof lengths are shown in Table 2 and Figure 2. 
Figure 1 – DeltaOrb DPP1110 Roof Sheeting 
Table 1 - DeltaOrb DPP1110 roofing profile variables used for calculations 
m 
D 
hol 
w' 
w'/D > 2.5? 
Use Eqn. 
D1 or D2? 
dm
(0.75*hol) 
w 
a' 
76.9mm 17.5mm 9.7mm 38.3mm 
2.19 
D1 
7.3mm 
33.8mm 157mm2 
Table 2 - DeltaOrb DPP1110 Maximum Roof Lengths for Rainfall Intensities 
Maximum Roof Length (m)* 
100I5 
ARI 
(mm/h) 
Pitch 
5° 
Pitch 
7.5° 
Pitch 
10° 
Pitch 
15° 
100 
24 
27 
30 
36 
150 
16 
18 
20 
24 
200 
12 
14 
15 
18 
250 
9 
11 
12 
14 
300 
8 
9 
10 
12 
350 
7 
8 
9 
10 
400 
6 
7 
8 
9 
450 
5 
6 
7 
8 
500 
5 
5 
6 
7 
*The designer and installer must provide allowances for thermal expansion according to AS1562.1:2018 and
other relevant design codes.
dm =
Area = 157mm2
w =
33.8
17.5
m =
D =
8.8
D/2 =
76.9
9.7
hol =
7.3
38.3
w' =

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