Replies

1. 
   Fbart | Aug 31, 2002 09:47pm | #1

   Henry: If your overhang is a dimention which is multipules of 5" ( assuming 5" exposure on shingles) or something close to it, you should be able to make your technique work.  How are you attaching the extention to the old roof and supporting it? Might be best if you could have your new sheething extend up onto the old rafters to help tie the two together. This however precludes the shinglers doing the whole roof before you start.  You could have them start 4'above the bottom of the new extention, and you procede as above. but that seems like a hassel.  As small as the roof is it might be as simple to shingle that side your self when you are done.  Good luck

2. 
   awschmidt | Aug 31, 2002 10:57pm | #2

        Here in climate heck (michigan), I do soffit additions frequently.  The "salt box" houses around here suffer from lack of soffit venting during our unstable winter freeze-thaw cycles and their general lack of adequate insulation.  When I do the job, I either cut the decking back 10" or (as is most often) I am replacing the lower most decking due to ice daming.  I sister (glue and nail method) rafter tail extensions of 24" length which allows 2 additional courses of shingles with plenty of support.  I usually use exterior screws in a quickdrive to attach the new decking, also use constr adhesive on low pitch roofs to add rigidity.  The soffit panels are supported by sleepers nailed to the house ext. wall and tails normally.  I have not tried preassembled soffit ext. but have seen them used before.  Basically, you would assemble the extension framing with a plywood back plate which is lag bolted to the original rafter tails.  I'm more comfortable with extensions transfering the load to the house frame (y yes i'm a german who does everything overkill), rather then expecting the lagged assy. to hold the snow load without roof line distortion.  oh yea, have the roofers order and leave you enough extra shingles so you can match what they are putting on.  nailing topdown is easy, but if your roofers are good, have them either short nail the first course or high nail (if weather in region and wind on that side of roof) to make your job "quick and easy".

         Kevin

   
   

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   Edited 8/31/2002 3:59:21 PM ET by MAULEBOY

3. 
   Piffin | Aug 31, 2002 11:37pm | #3

   It's hard to imagine a "technique" that will do this adequately without tying into the roof similar to what these guys have mentioned. Beyond that, yes, it is possible to lay up under but the roofers need a line from you to start from so that the exposures will run even. It's better for them to run a little low though. eg. if your exposures are 5" and you allow them 20" but make a 1" mistake high, it'll be hard to hide but if 1" low you can just go to 4-3/4" exposure per run to use it up. Go over the recommended exposure to 5-1/4" and you void the warrantee.

   Excellence is its own reward!
1. 
   RobP22 | Sep 01, 2002 02:34am | #4

   Sounds like a plan. In defense of my own techniques. Yes I did tie the tails to the existing rafters with sufficient overlap to provide planty of nailing area. And I nailed the sheathing into the "scab rafters". My overhang is very strong and secure. My main concern was shingling the new area so it would blend nicely with the rest of the roof.

   Both the roofers and I agree this would have been a much simpler project if the owners gave me more time to complete framing the overhangs before the new roof went on.  

   Thanks for the tips.

1. 
   rez | Sep 01, 2002 02:40pm | #5

   Henry- Was wondering how far up the existing rafter you place the new 2x and how long that 2x is? What nailing pattern do you use to secure the two together?Half of good living is staying out of bad situations.

1. 
   RobP22 | Sep 01, 2002 08:40pm | #6

   I used 2x6's 6ft long, 16" o.c. with 3ft overlap onto the existing rafters and after the tail cuts were made the overhang came out to 18". I used the cutoffs for blocking in between the rafters. I think the term for the blocking is "frieze" blocks. I'll pull several blocks out later for ventilation. I nailed 1 ft in from the high end of my "scab rafters" in a pattern like this:

   . .

   .

   . .

   each n represents a nail. Then where my rafters bird's mouths meet the top plate, I toe nailed from each side into the plate and put two more nails into the overlap just above the plate. So it came out to 9 nails per rafter that way. I also nailed the sheathing into the overlap areas making sure I spiked into both old and new rafters. I weigh 200lbs and I suspended myself from the edge and it did not budge. The roofers also had no problems with the rigidity of my overhang.

   The roofers who followed me on this job comlained that I left high spots and they had to trim the tops down on some of my rafters and blah blah blah, but I looked at the finished work today and it looked good. With these old houses settling and all, it is a real pain to get everything straight and level. Next time I will probably recommend leaving well enough alone. If you want perfect build new.

   Have fun crawling around in the attic.

   Edited 9/1/2002 1:49:47 PM ET by Henry

   Edited 9/1/2002 1:50:21 PM ET by Henry

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   Edited 9/1/2002 1:51:49 PM ET by Henry

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   Edited 9/1/2002 1:54:27 PM ET by Henry

   Edited 9/1/2002 1:58:52 PM ET by Henry

1. 
   rez | Sep 01, 2002 09:24pm | #7

   Thanks Henry-  Good stuff.Half of good living is staying out of bad situations.