Bonnet or gable hip

Figure 7.5 illustrates a typical construction for this hip form. To carry the weight of the hipped element of the roof, the Fink of the main roof would probably not be strong enough on the bottom chord. The Howe configuration has an extra support on the bottom chord, dividing the span into four rather than three bays of the Fink. Again a girder will be formed of two (or three) Howe trusses, and this time the monopitch truss will definitely be bottom-chord supported in truss shoes. The upper part of the Howe (that triangle above the monopitch roof), will have to carry some form of cladding, possibly rendering or boarding. The additional weight of this cladding must not be overlooked when designing the truss.

Exposed triangle at end of ridged roof

Compound or multi-ply truss

Eaves fixing

Truss clip

Exposed triangle at end of ridged roof

Compound or multi-ply truss

Eaves fixing

Truss clip

30 x 5 mm galvanised wall tie

TW962 truss shoe supporting monos and loose ceiling joists

30 x 5 mm galvanised wall tie

TW962 truss shoe supporting monos and loose ceiling joists u o f

Fig. 7.5 Bonnet or gable hip trussed rafter layout.

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