Oblique Hip Roof Pictures & Text from previous Trade notes – course 5158 M. S. Martin – June 2005 Revised – February 2008

Ridge Gathering Detail Copy detail into student notes, top of page

Set out of members Add to text notes bottom of page The first members marked on the top plates being the centre lines for crown end and centring rafters, with the remaining common and creeper rafters measured into and over from these members.

Set out continued 1)Lengths of oblique end and offset established (eg) Oblique end = 6.400m Offset = 3.800m

Set out continued Copy into notes bottom of page 2) If the ridge was extended it would bisect the oblique end. 3) This point ‘x’ is transferred to the offset and bisects the offset 4) Half the oblique end is the radius of a semi-circle. XA = XC = XB. Therefore XC is equal to half the oblique end.

Position of Centring Rafter Copy into notes 5) Distance BE = Half Oblique end minus half the offset 6) Distance DA = Half Oblique end plus half the offset

Position of Crown End Copy into notes 7) FB is equal to BE (similar triangles)

Creeper set out Copy into notes 8) Thickness of material marked on the centre lines and remaining creepers set out, into and over.

Establishing Bevels Just like any other roof you have done, the bevels can be established in a number of ways, the oblique end is no different Geometrically Direct Method or Steel square Your first drawing will be to establish these bevels geometrically Example on next slide