I am no engineer, however, while it may be theoretically possible to convert
rafters and ceiling joists into a truss, most roofs are not constructed in a
way that would allow a conversion to a truss, most notable the connection
between the rafter and the joist at the outside support walls plus any
splices or joints in the ceiling joists that may not align or not have any
torsional strength. Trusses are normally built unloaded, installed and the
load added. It would be difficult to conceive how to build it in place while
under load.

If you are just supporting a ceiling and not a second floor, it should be
possible to add a modest size gluelam beam to support the ceiling joists.
Getting it up and in the attic is the biggest challenge, but you may have
the same problem getting wood up and installed to create trusses.

wrote in message
...
Hi All,

I want to remove a load-bearing wall that separates my living room
from my kitchen. The attic is constructed of regular roof rafters and
the span is roughly 25 feet. I'm exploring different methods of
accomplishing this. The obvious method is to install a beam, but I
also want to look into the prospect of converting the existing roof
rafters into trusses. I've been unable to find much useful
information online so far.

Can anybody recommend any resources (preferably online) that detail
the pros, cons, risks, and methods for a do-it-yourselfer to do such a
conversion? I don't know if I will do it this way or not, but I would
like some reputable websites that would at least tell me whether or
not I can.

Thanks to everyone for any information you can provide!

Ken