RossJarvis
Established Member
I may be cutting some rafters soon on two pitched roofs meeting at right angles and can't remember much about setting out the compound cuts.
I recently cut some "cripple rafters?"(ridge to valley) into an existing arrangement and set the CMS using a sliding bevel off some batten and the valley rafter, which worked out pretty well.
For cutting for a virgin roof I seem to remember that when marking out compound mitres for hand saw cuts it all got a bit complicated as the valley angles aren't straight 45 degrees, due to the effect of the pitch angle and probably involved knowing how to use a "rafter square" (I've forgot
) or phoning Pythagoras up. Is it necessary to do complicated geometric shenanigans on a CMS or do you just set the pitch angle and 45 degrees (or is it the opposite of the pitch angle...scratches head :? )?
Gentle answers for an idiot please, or links to an idiots guide
I recently cut some "cripple rafters?"(ridge to valley) into an existing arrangement and set the CMS using a sliding bevel off some batten and the valley rafter, which worked out pretty well.
For cutting for a virgin roof I seem to remember that when marking out compound mitres for hand saw cuts it all got a bit complicated as the valley angles aren't straight 45 degrees, due to the effect of the pitch angle and probably involved knowing how to use a "rafter square" (I've forgot
) or phoning Pythagoras up. Is it necessary to do complicated geometric shenanigans on a CMS or do you just set the pitch angle and 45 degrees (or is it the opposite of the pitch angle...scratches head :? )? Gentle answers for an idiot please, or links to an idiots guide
