Installation Guide

Shakes
In shake application, battens of 25 x 50mm minimum
are spaced on centres equal to the weather exposure
(Table 4, page 16) at which the shakes are to be laid,
measured from 38mm past the fascia board.
Maximum weather exposure for 455mm shakes is
190mm, and for 610mm shakes is 255 mm.
Breathable membrane interlay at the eave and between
the shake courses is required whether battens or solid
sheathing is used. The felt interlay, complying with
BS747:4016/5250/5534, acts as a baffle that prevents
wind driven snow or other foreign material from
entering the attic cavity during extreme weather
conditions. The interlays also increase the roof’s
insulating value. The first row of 1 metre felt interlay
is placed at the eave line, then the first double course
of shingles or shakes is applied, overhanging the fascia
by 40mm. The next row of .5 metre felt paper is
placed so that its lower edge is at a distance of twice
the weather exposure from the butt. Installing the felt
paper any lower will expose it at the gaps between
shakes and detract from the roof’s performance.
The top of the felt paper should be tacked to a batten.
When succeeding rows of felt paper are then installed
at the actual weather exposure distance, the bottoms of
the felt paper rows will act as convenient placement
guides for the butt lines of succeeding rows of shakes
(Figure 5). The tips must be tucked under the second
row or felt paper as application proceeds up the roof.
Shakes, like shingles, are normally applied in straight,
single courses. The split face is always installed to the
weather, the sawn face to the deck. The starter course
may be one or two layers of cedar shingles or shakes,
overlaid with the desired shake. Spacing between
adjacent shakes should be a minimum of 9mm and
maximum of 16mm. Joints between shakes should be
offset 38mm over adjacent courses (Figure 5).
Fig. 5 Shake Application
3
Felt laid over top portion
of each course
Spaced sheathing
should be 19mm x
140mm or wider
Eave protection
380mm starter course
Rafter
Rafter header
Drip edge 38mm
Fascia
Gutter
Adjacent courses
should be
offset 38mm minimum
Exposure
Nail with 2 nails per shake
approx. 19mm to 25mm from edge
and 38mm to 50mm above butt line
Space shakes 9mm to
16mm apart