Roof Framing

Started by dougpete, September 03, 2010, 11:14:52 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.


Greetings -

We modified the Universal 20 x 34 to be 24 x 34, using a bearing wall in the basement, 1st floor and second floor.  I have 2x10 o.c. attic joists and have been planning on using 2x8 o.c. rafters going up to a 2x8 ridge board.  (I used a program called Easy Rafters)

Now I am not so sure this will work - I would prefer not to use collar ties if I can avoid it as the roof will be much easier to insulate and drywall if I don't.

Should I use a ridge beam instead?  If so, how can I find out how big it needs to be?




The basic idea will work fine.

If your 2x10 attic joists are tied to the rafters and to each other... in other words if you are building a triangle, you have a stable roof. The attic joists are the required "rafter ties". So a ridgeboard will work, no need for a ridgebeam yet.

The ridge board needs to be at least the depth of the plumb cut on the top end of the rafter. Since the rafter is cut at an angle up top the ridge it meets will need to be a size or two deeper than the rafter material. 

"Collar ties" are needed at the tops of the rafters. These are either ties from rafter to rafter up under the ridgeboard, or anywhere in the upper third of height, OR meatal strapping up over the ridge tying rafter to rafter over the top.

The rafter depth is determined by your snowload.