We are remodeling a cabin in the mountains and are presently expanding the porch and house roof out over the deck. I replaced the railing posts with columns and installed double 2x beams. I had to build a small knee wall above a cross member to support the continuation of the porch rafters and the house roof rafters on one side. The other end will be supported by bearing walls for a mudroom that stops at the roof peak and extends outward the width of the deck.
I ran into a problem as I began running the porch rafters to match the pitch and overhand of the existing porch rafters. All was fine until I reached the 45 degree section of the new porch beams. As I turned the rafters 90 degrees to cross the 45 degree angle, each successive rafter became increasing higher from the top of the beam because the point where the rafter crossed the beam naturally moved closer toward the knee wall and causing the distance between the bottom of the rafter and the top of the beam to increase. By the time I reached the far end where the 45 met the outside beam, the distance between the rafter and top of beam was 3-1/2" inches. So in order for the top of the roof to remain level across the width of the roof expansion, I found it necessary to gradually raise the rafters over the 45 degree area.
The roof is level but when viewing the overhang from underneath, there is a very obvious increasing space from the farthest point of the 45 from the knee wall to the nearest point to the knee wall where it meets up with the outside beam. I realize that it's occurring because the rafters are crossing over the 45 degree area of the beam at different points and their pitch is producing the increasing space in relation to the position of the beam under them. The question is how can this area be framed to avoid such a circumstance? I tried running the rafters both 90 degrees to the 45 in that area and then just running them straight across it but it obviously makes no difference because the rafters nevertheless cross the 45 area of the beam at different points that produce a gradually increasing space. I've attached a drawing that is not to scale but generally depicts what I'm working with at this area of the house.
The roof obviously has to remain level and the rafter problem described is also going to produce a sub-fascia and fascia that will rise from one end of the 45 to the other end, a height differential of 3-1/2 inches and making it out of level with the beam below it. There obviously must be some way to frame this area to avoid the problem but I'm overlooking it.
Any help here would be much appreciated.
I ran into a problem as I began running the porch rafters to match the pitch and overhand of the existing porch rafters. All was fine until I reached the 45 degree section of the new porch beams. As I turned the rafters 90 degrees to cross the 45 degree angle, each successive rafter became increasing higher from the top of the beam because the point where the rafter crossed the beam naturally moved closer toward the knee wall and causing the distance between the bottom of the rafter and the top of the beam to increase. By the time I reached the far end where the 45 met the outside beam, the distance between the rafter and top of beam was 3-1/2" inches. So in order for the top of the roof to remain level across the width of the roof expansion, I found it necessary to gradually raise the rafters over the 45 degree area.
The roof is level but when viewing the overhang from underneath, there is a very obvious increasing space from the farthest point of the 45 from the knee wall to the nearest point to the knee wall where it meets up with the outside beam. I realize that it's occurring because the rafters are crossing over the 45 degree area of the beam at different points and their pitch is producing the increasing space in relation to the position of the beam under them. The question is how can this area be framed to avoid such a circumstance? I tried running the rafters both 90 degrees to the 45 in that area and then just running them straight across it but it obviously makes no difference because the rafters nevertheless cross the 45 area of the beam at different points that produce a gradually increasing space. I've attached a drawing that is not to scale but generally depicts what I'm working with at this area of the house.
The roof obviously has to remain level and the rafter problem described is also going to produce a sub-fascia and fascia that will rise from one end of the 45 to the other end, a height differential of 3-1/2 inches and making it out of level with the beam below it. There obviously must be some way to frame this area to avoid the problem but I'm overlooking it.
Any help here would be much appreciated.
