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Framing Common Roofscapes
Dog Leg or Skew Corners
A dog leg or skew corner is formed by the intersection of two roofs at an angle other than 90 degrees.

It is usual for the incoming and outgoing roofs to have the same span and pitch, although it is possible to frame the roof using trussed rafters, if these differ.

The cross section may be of any of the usual shapes but is generally mono-pitched or duo-pitched.
The typical framing plan shown for a duo-pitch roof is characterised by the minimum number of different truss types and provides a practical solution to the problems raised in these situations but using loose infill.

The multi-ply girders used have a number of vertical webs to allow the fixing of the loose timber purlins, which support loose timber rafters. 
The example shown needs a lot of site loose work. However now that there are proprietory metal hangers available to join trusses to girders at angles other than 90 degrees the whole of the corner could be framed with trussed rafters.
The feasibility of this framing method depends on the design of the longest purlin. Although installation of loose ceiling ties from girder to girder may be
simpler in carpentry requirements, it is generally preferable to adopt the layout shown (incorporating loose timber binders at ceiling level), in order to
simplify plasterboarding.

The ceiling binders should be supported on the bottom chords of the girders and located against the vertical webs. Arobust structural connection for example, with two proprietary angle plates should be made between binders and loose ceiling joints. The ends of the binders may need to be notched or blocked-up off the girders, to ensure that the undersides of the loose joists
are level with the girders.