hip cut

[Larry]

Can someone tell me how much to drop the birdsmouth cut or how much to bevel the top of the hip rafter on a hip roof? I want the underside and top to plane in. I mean I will be sheathing to top of the rafters and adding paneling to the underside. I will use 2x6 rafters and I thought doubled 2x6 hip to keep the hip from "hanging" below the jack rafters. It been many years since I've stick framed a roof, all roofs are trusses so I am rusty. Larry

[Joe Carola]

Larry,

All you have to do for the drop is to mark your hip length plumbcut line (outside corner of plate) at the birdsmouth and then come in plumb towards the top plumbcut (ridge end) 1/2 the thickness of the hip which in your case would be 1-1/2" for your double 2x6 hip and then mark the HAP cut (height above plate) the same as the common HAP cut and that will plane your hip in at the top with the rest of the commons.

Joe Carola

[Joe Bartok]

Is the Hip roof two equal pitches with the eaves meeting at a 90° angle in plan? Calculations for bevelling, hip drops, and matching the Hip rafter to Common rafter depth are affected by changes in pitch and plan angle.
I want the underside and top to plane in.
Larry, do you mean plane in only to the flat, or do you intend to back the inside and outside of the Hip rafter? I assume you intend to back the Hip rafter inside as well if you're panelling. Not trying to be picky, just making certain I understand your question.

[R Birch]

Larry,

There is a thread topic at the bottom of the topics list about this subject. (Hip and Valley rafter heel height adjustments)

http://www.construction-resource.com/forum/ftopic3070.html

Joe Carola’s explanation above is a simple way to do it for Regular Hip/ Equal Pitched Roofs.

I always use 2/8 (or better) rafters for chamfered ceilings, above the plate height, under a Hip. A double 2/6 Hip will most likely sag. It does not offer much strength or room for insulation. I use a double 2/10 Hip and rip the area of the ceiling to plane with the 2/8 jacks.