|Forum topic by PaulMD||posted 09-15-2015 10:23 PM||633 views||0 times favorited||1 reply|
09-15-2015 10:23 PM
Ok I am planning out the replacement of the roof on my 1950’s Cape Cod.
I spoke with the local Permits office and ended up as confused as before I started talking to them.
My current roof system has 2×6 rafters (actual 1 7/8” x 5 3/4”) with 1×4 purlins and metal roofing (older rib style w exposed fasteners) with a 7:12 slope/pitch. The metal roofing has been neglected over the years and cannot be saved at this point.
The rafter span is 12’6” (house is 30’ x 25’ with the ridge running the 30’ length ) with a length of 16’ per rafter. The second floor of the house has finished bedrooms with plaster walls/ceilings (approx 1” thick). From what I have seen the roof would be considered a light roof for dead load purposes and based on my location there is a 40 psf snow load.
I am planning on replacing the roof with a composite shingle roof system (5/8” OSB, ice/water, felt and architectural shingles).
Based on the current load span charts modern 2×6 lumber will not be sufficient to support the roof system (i cant seem to find any older span charts that would cover the larger 2×6 rafters that are installed on the house) and I was told by the Permits guy that I could “sister” a second 2×6 to the existing rafters but he would recommend “sistering” a 2×8 to the existing 2×6 rafters”.
Anyone have any idea what the load span of sistering 2 – 2×6 rafters is vs sistering a new 2×8 to the existing 2×6?
I am planning on doing the ‘glue and screw’ type of mating the new rafters to the existing ones I just want to make sure I select the correct size for the new rafters.
Based on what I was told from the permits office I do not need to pull a permit to replace the roof and from the sound of it they didnt really seem to want to be bothered with it lol.
Thanks for any help with this.