Replies

1. 
   ripmeister | Jan 18, 2005 06:15pm | #1

   It all depends on species etc.  Consult a span table.  My guess is that since this was a set plan you found and you are going to extend the span that you will need to beef up the rafters.

1. 
   dad6b | Jan 18, 2005 06:41pm | #2

   How do the cross-ties factor into the load it will hold? Would I need to beef up the rafters, the cross ties or both?

1. 
   ripmeister | Jan 18, 2005 06:58pm | #3

   I'm not sure about the cross ties.  I'm not a framer but my understanding of cross ties is that they work against lateral forces, i.e. walls spreading.  Why cross ties anyway, and not just ceiling joists?  Is the ceiling going to be open?

1. 
   dad6b | Jan 18, 2005 07:09pm | #4

   Yes the ceiling will be open.

1. 
   ripmeister | Jan 18, 2005 07:54pm | #5

   perhaps someone more knowledgable than I will respond but I don't think you would have to change the ties unless by the fact that you change the rafter size which would increase the dead load of the roof you also increase the lateral force.  I don' t think however that would necessitate increasing the size of the tie.

2. 
   woodguy99 | Jan 18, 2005 08:43pm | #6

   Dadunn, depends where you are.  Roof loads vary a lot depending on what part of the country you're in.  Can be snow, wind, or seismic loads.

   Here in southern New England, you would probably need to size up the beam and rafters, but the rafter ties would probably be ok.  You really need to talk to a local contractor, architect, or engineer.

1. 
   dad6b | Jan 18, 2005 09:12pm | #7

   Thanks, I figured I would need to talk to an architect but I was hoping to figure out as much as I could on my own first.