# How to frame a curved porch roof



## hick23 (Apr 11, 2012)

Hello, I'm adding a porch and am wondering how you frame a roof like on the front porch of this house. It's a cathedral ceiling, but the beam is not supported on the front or doesn't appear to be and there are no collar ties to stop the sides from pushing out. Does anyone have any information on how this would be framed?

http://archadeck.files.wordpress.com/2012/10/front-porch-montgomery-maryland.jpg


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## GBrackins (Apr 26, 2012)

they could have used rafter ties. a rafter tie is a means of constructing a structurally sound roof without the need of a ridge beam or ceiling joists. basically if you measure from the bird's mouth (where rafter sits on beam) to the ridge a rafter tie would be located in the lower 1/3 of that distance. it is normally installed on the side of the rafters to connect them together and looks like the letter "A". if the rafter tie is located at the bird's mouth we would normally refer to this as a ceiling joist.

you would then frame the barrel vault ceiling using the rafters and rafter ties.

Hope this helps.


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## roofguy (Feb 5, 2012)

I frame barrel vaults, most of the time I use 4x8 to sheathing make my arches. then make multiple patterns. then strap it with ferring. hope that helps


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## sixeightten (Feb 10, 2009)

The front arch there also serves as a collar tie.


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## oh'mike (Sep 18, 2009)

Front of the arch is often made of a doubled sheet of 3/4" ply (1 1/2") that is plenty of strength to keep the structure straight----


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## Willie T (Jan 29, 2009)

Interesting. I'd almost bet that roof would be done with small scissors trusses today.


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## GBrackins (Apr 26, 2012)

scissor trusses would certainly work!


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## hick23 (Apr 11, 2012)

I like the idea of the plywood. I'm not too sure if I could get scissor trusses that could spand the 9 feet I have to span but I will look into it.


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## Willie T (Jan 29, 2009)

hick23 said:


> I like the idea of the plywood. I'm not too sure if I could get scissor trusses that could spand the 9 feet I have to span but I will look into it.


Do you feel it is too short a distance?


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## mae-ling (Dec 9, 2011)

I could get Trusses including scissor trusses any size I wanted.
The idea of double 3/4inch plywood for the gable end is good.


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## GBrackins (Apr 26, 2012)

if you're looking to use plywood for the ceiling of a barrel vault ceiling I'd recommend checking out the required bending radii for plywood from the Engineered Wood Association. 


http://www.apawood.org/level_c.cfm?content=pub_searchresults&pK=bending%20plywood&pT=Yes&pD=Yes&pF=Yes&pubGroup=tch

sometimes it is easier to use two layer of thinner plywood that attempting to bend a thicker panel.


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## paintdrying (Jul 13, 2012)

wow, who put all those plumbing vents on the front of that house.


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## oh'mike (Sep 18, 2009)

mj12 said:


> wow, who put all those plumbing vents on the front of that house.


I'll meet you there with a case of Hula Hoops --we can play 'roof top ring toss'---:laughing:


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