Page 34 - Build 161

roo ng
● 90 mm for all roof pitches for EH wind zones – E2/AS1 Table 7, Situation 3 and Figure 47.
Barge ashing cover over roo ng is the same as for apron ashings installed parallel to the roof slope.
Eaves ashings
E2/AS1 requires eaves ashing (see Figure 7) to be installed with long-run pro led metal roo ng in VH or EH wind zones where the roof slope is 10° or less and the so t width is 100 mm or less from the cladding.
The ashing must extend 125 mm back up under the roo ng and have a 35 mm overlap to the back upstand of the gutter – E2/AS1 Figure 45(a).
Ridge and hip roof ashings
Ridge and hip ashings (see Figure 8) for pro led metal roo ng must provide a minimum cover as for apron ashings. They must have:
● soft edges dressed to a corrugated pro le –
E2/AS1 Figure 41
● the edges turned down and notched to
accurately match a trapezoidal pro le, leaving a 5 mm gap between the ashing and the cladding – E2/AS1 Figure 42.
All troughs ending under a ridge or hip ashing of pro led metal roo ng must be turned up.
Metal tile roofs must be installed with preformed ridge caps of 35 mm over 40 mm minimum metal tile upstands – as detailed in E2/AS1 Figure 34.
Clay and concrete tiles must have a ridge tile as shown in E2/AS1 Figure 23, bedded in mortar with weepholes at the pan of each tile.
roof underlay
rafter
125 mm minimum
Eaves ashing required when: • roof pitch ≤ 10° and
• so t width ≤ 100 mm and • in VH and EH wind zones.
fascia
spouting
35 mm
Figure 7
Eaves ashing.
Ridge/hip ashing should be:
• 130 mm minimum for L, M and H wind zones where roof
pitch is ≥ 10°
• 200 mm minimum for L, M and H wind zones where roof pitch is
< 10° and all roof pitches in VH and EH wind zones.
roll top ridge ashing
stop-ends to corrugates
corrugated roo ng
soft edge dressed over corrugate
purlins
roof underlay
Figure 8
Ridge/hip ashing (non-vented).
32 — August/September 2017 — Build 161