How to cut bevel lengthwise along rafter

I'm planning a garden office where the roof is angled diagonally, so one corner will be lowest, the two adjacent corners will be mid-height, and the final corner will be the tallest. The gradient of the roof will be in the range 1:10 to 1:12.

For this to work, the rafters will need to have a bevel along the top. This is so that the rafters, which will be 2x6 timber, can sit vertically on the frame, but accommodate the roof boards which will be at an angle. They'll already have the right angle end-to-end because they'll be sitting on frames.

How could I cut a bevel along the length of the rafters?

Options I've considered are:

• A track saw
• A hand plane
• A band saw

I have a track saw and a hand plane, but I'm not sure if these are good options. I have a router, but I can't figure out how I could use it to make a bevel. I guess I could use a table saw, but I don't have one, and I'd prefer not to have to use one unless it is the only way.

I haven't managed to find any description where someone has already done this.

• Oh this is easily done on the bandsaw, you just need to arrange a tilted fence. As you know this is a bevel cut, as distinct from a chamfer, but the two terms can be and are frequently mixed up these days. So that might help searching out other people who have done this in various ways. Anyway, although a lot of work you could quite simply do this with 'a' handplane (many would want to use more than one) but it would depend on what you had available... could be done with a no. 4 if you absolutely had to, but a plane with a noticeably cambered edge on the iron would make it a lot easier. – Graphus Apr 1 at 16:12
• If I understand correctly you are spanning the rafters across the roof rather than from top to bottom. Most rough carpentry framing of this type would be executed using a rough carpentry circle saw. Just set the blade angle and run it up the length using the corner as your guide. – Ashlar Apr 4 at 2:16