I’d like to first thank all for the help I’ve received in designing my front porch. I’m now to the roof structure. This is a gambrel roof where the porch roof will be coming off the long side that is perp to the gable ends. The existing roof that is the steep portion curves into what become the soffits. I’d like to keep this detail for the new shed porch roof, that is as I bring it from under the second floor windows out to the outboard posts I would like to have it curve from a steeper pitch into a flatter one.
My original design was a simple 3/12 shed roof that would extend out about 12′. Now that I am considering this new design the question is how to come up with rafters that would allow this curve. What would be a good way to do this. In addition would one use skip sheathing thru the curve portion of a roof deck such as this?
By the way what is the term for the side of a structure that is perpenduclar to the gable ends?
Replies
Non- pointy?
The other sides?
Not being glib, I can't think if they have a specific name....long side?
"If 'tis to be,'twil be done by me."
Cut straight rafters that are extra fat, tens should do depends on the curve. Try with one as a sample. Lay out the curve with a thin strip of quater or half inch, anything that'll bend without being floppy. You can estimate the existing by laying a straight edge on it an measure the farthest point over the span of the straight edge. If the existing won't match start with a shallow curve and trust your judgement. Draw what looks good to you. Cut the rafter, jigsaw works best but a circular saw can do it unless it's too tight a radius by starting shallow and following with progressively deeper cuts. Don't force it, if you bend a blade no biggie but you don't want to bend the arbor. Listen to the saw, if it sounds like its complaining ease up. If you make extra cuts to the waste side of the line you'll give room for the blade. Relief cuts perpendicular to the tangent of the curve will help.
Once you get a close match use it as a pattern for the rest of the rafters. Try to place the rafters so that they stack up onto the wall studs. If in doubt add some. To sheet the roof use 1/4" ply, it should bend with some coaxing. Layer it up , staggering end joints and seams and don't be shy with the nails. You could use construction adhesive between layers but that may be overdoing it, not necessarily a bad thing.
The walls perpendicular with gables are known by too sets of terms, depending on where the main entrance is; either front & back or left side & right side. They will also be load bearing walls.
Get your curved rafters from Home Depot.
GDR
~Peter
"The way to find out who you are is to ask yourself, "Who amI?".
I'm with MBDyer on the technique. The term you're looking for is "eave side," as opposed to "gable end."
Mike
Thanks Mike, I thought it might be eave side just wasn't sure of the nomenclature. Without the help of pictures I've always found it helpful if one can use descriptors that are concise and specific.
the "ROOF"??!!
"I think natural selection must have greatly rewarded the ability to reassure oneself in a crisis with complete bull$hit."
Witty tagline...
say what?
The ROOF is the part of the building perpendicular to the gable end"I think natural selection must have greatly rewarded the ability to reassure oneself in a crisis with complete bull$hit."
I'm Swiss!
In retrospect I missed your mention of "skip sheathing". What is your planned roofing material? Whatever it is I would still lean towards sheeting with ply and then felt at least. Ice and water shield would work better and may bot be cost prohibitive if the roof is small enough. On top of this you could then nail down the battens for the shakes or what not. If 3/4" strapping won't bend to fit, use the same principle as for the sheeting and rip strips of 1/4" ply and build the strips up. Time consuming but then everything dealing with curves takes more time. I examined a Japanese roof at the Phila Art museum, or was it Brooklyn?, where they made the roof from shakes with only a 1 1/2" or 2" exposure. I think they may have actually soaked them and put them up wet to form the curve-drainage is obviously key. Then end result was very interesting asthetically speaking.
Thanks for the response. I did plan on using bitumen over the entire porch roof structure since it will be low slope, along with archy shingles at a small exposure. I asked about the sheathing because I wasn't sure how best to deal with the curve either with say 1x3s that could follow the curve fairly well or with bendable ply as you suggest. I do most of my own work but will be hiring out the framing on this job so I was just wondering what would be the best approach to put in my plan for the framers.