We have an addition with a shed dormer coming up. It’s Cape Cod style second floor with a shed dormer that spans 22′ or the total 24′ width.
Since the shed portion breaks up the tie that the ceiling joist provides in a normal roof situation, we need to have a structural ridge. I spoke with our engineer today and proposed a possible solution to the problem of the large ridge beam.
What I think may be possible (I have no idea if it’s cost prohibitive, that’s really not the point) is to use some LVL rafters in the center of the ridge span that would run from the plate of the wall that the second story rests on up to the ridge to create the “truss” section.
There is a partition wall in on the second floor that we could use to conceal this rafter, so in essence the shed dormer would be brokin up in to two sections.
Like I said, I’m not sure if this is practical but after my conversation with the engineer I have no information other than “it won’t work”. I realize that the rafters that we place to support the ridge may very well have to be huge to carry the load, but I’ve seen this detail with timber frames and I think Mike Smith may even be doing something similar on the “Adverse Conditions” job.
Am I batty or is my thinking relatively on target?
Replies
Ignoring the sizing issue ...
If you do it right it will work.
But then you are not paying me to do the engineering. Always leave with the girl you brought.
GHR,I assume that you are an engineer by your comments.If so, I have a question for you, what questions should I be asking my engineer to get the response I desire, which is an intelligent explanation of why or why not my idea will not work?P.S.- I never asked you to do the engineering for me.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
JonBlakemore ---I would suggest you take the picture you have and offer to pay him for his time.Ask him:1) How much load would be on this truss?2) How big would the members need to be?3) How would the load get to the foundation?
GHR,Thank you for your advice. I will see if it works.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Jon,
Do you have a side view of what you want to do? I'm trying to figure out why you need a structural ridge. Are you using the existing ridge and keeping it cathedral?
Joe Carola
Edited 3/27/2006 5:39 pm ET by Framer
Joe,This is the top floor of a Cape Cod, the back portion has a shed dormer running almost the full length. Since most of the rafters on the back do not fasten to the ceiling joists we will need to support the ridge, right?
Jon Blakemore RappahannockINC.com Fredericksburg, VA