Replies

1. 
   Guest_ | Jul 31, 2000 08:33pm | #1

   *
   If the rafters at the wall ends are to be connected by joists...then the ridge board is unsupporting and does no more then make assembly easier...The rafters should be tied together still at the peak to resist the wind driven forces of uplift and such....

   If your ridge is to be supporting all then a trip to the lumber yard will answer your questions....They have charts and if needed a call to an engineer and or truss plant or beam company...

   near the stream,

   aj

1. 
   Guest_ | Jul 31, 2000 09:04pm | #2

   *What AJ said!If the attic space has floor joists or if there are collar ties to keep the walls of the house from spreading, than you don't even need to use a 2x12. Anything to but the rafters against will work.If there is nothing to stop the walls from spreading, the ridge board will sag, the rafters will drop and the walls will spread out in a few years. (or as soon as you start to roof it) In this case you need a "structura' ridge beam" such as an LVL sized accordingly and supported at each end.

1. 
   Guest_ | Jul 31, 2000 10:40pm | #3

   *I probably should have provided a little more detail the first time around. The house is a 1 1/2 story, 10/12 in front and 4/12 in the back. Back rafters are 2x8, fronts are 2x12 for cathedral ceiling.There are no true collar ties. There are some 2x8's that span from the second story wall/ceiling joist to the 2x12's. This creates the peak of the cathedral ceiling.

1. 
   Guest_ | Jul 31, 2000 11:14pm | #4

   *If I understand correctly, the part of the house that has a second story has ceiling joists that run from the outside wall to the rafters on the front of the house.If this is right, the rule of thumb is that these are effective collar ties if they are no higher than 2/3 of the way up the rafter. If they are higher than that, they're not effective. Of course, this is an area where bolting pattern, is also important.Sounds like this is more complicated than most roofs and you might want to have an engineer look at it. Or, even have custom trusses made that you know will do the job. Trusses are cheaper and easier than stick framed roofs almost all the time. I love trusses.

1. 
   Guest_ | Aug 01, 2000 05:01am | #5

   *It sounds to me like a 10:12 pitch on the front slope (forming a cathedral open the the first floor below), and a 4:12 pitch on the back slope, to enclose a second floor living area.What I'm seeing here is a need for a ridge beam supported by a bearing wall... in cross section, a triangle in the front, a parallagram and rectangle in the rear. Sort of the classic "shed dormer on the back of a cape support problem", only made more critical by the absence of first floor ceiling joists in the front section of the house.But heck, it's late, and maybe I don't have the right picture...Drowsily, Steve