A Stratco Clearspan attached on its side to a house is attached to
the existing eaves overhang at the fascia, or to an existing wall if
height permits.
The first objective in the construction is to fix a structural side beam
along the fascia or wall, to which the Gable Unit is attached. Most
existing houses have not been designed for the attachment of portal
framed gables to their side, therefore additional strengthening of
the house rafters must be performed. In order to strengthen the
existing house rafters, the roof tiles or roof sheets need to be lifted
to expose the roof frame. Steel rafter brackets and channels are
then bolted along the house rafters.
An attachment beam is bolted to the strengthening brackets at the
fascia. Once the attachment beam is secured to the house, the Gable
Unit can be erected and fastened to the beam.
The first step is to determine the number of rafters which need to
be strengthened and their location relative to the unit. You will have
to lift some roof tiles or roof sheets to discover the rafter positions
and spacings. The number of rafters which need to be strengthened
is determined by the builder, however spacing is recommended not
to exceed 1200mm.
Note: It is the builder’s responsibility to ensure the existing
rafters and fascia are adequately reinforced and strengthened to
accommodate any additional attached structure. The reinforcing
method must be approved by the appropriate council or engineer.
It is recommended an adjustable rafter strengthening bracket is used
in conjunction with an extension channel, as shown in figure 3.0.
The adjustable rafter strengthening bracket is shown in figure 3.1.
Figure 3.0
Figure 3.1
Figure 2.0
Before erecting any valley beams the capping needs to be fixed to
the top of the beams. The beam capping will support the Cooldek
when it is laid and the gable brackets will be attached to the beam
capping. When fixing the beam capping ensure that the double
thickness of the beam is on top.
Fix the beam channel to the top of the valley beam using 12x20 hex
head self drilling screws at maximum 500mm centres and with two
screws at the location of all rafters as shown in figure 2.0. Fix the
beam capping to the channel using 3mm rivets or 12x 20 hex head
screws each side at maximum 500mm centres and with two rivets
either side of the location of all rafters. Ensure the break is located
in the top groove (figure 2.0).
If attaching the valley beam to a header beam, notch the capping so
that it sits on top of the header beam as shown in figure 6.6.
VALLEY BEAM ASSEMBLY
ATTACHING ON SIDE TO HOUSE
locate the break
on the capping
in top groove of
valley beam
fix beam capping to channel
using 3mm rivets each side at
500mm centres. Fix with two
rivets either side at the location
of a rafter.
fix beam channel to top of valley
beam using 12 x 20 hex head self
drilling screws at 500mm centres.
Fix channel with two screws at the
location of a rafter.
valley beam
beam
channel
beam capping
timber rafter
M12 bolt
rafter
strengthening
bracket
60x44x2.0 G450
galvanised channel
Adjustable Rafter
Strengthening Bracket
