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Architecture/Needing a rough idea about a contruction problem


Hi and thanks very much in advance,

We have a detached garage pad that was wiped clear of the garage by a hurricane a few years back and I'd like to construct a 20x20 workshop in its place.

To collect rainwater (and look kinda cool) I'd like to use an offset, galvalume, "V"-shaped roof sloping up from the center 8 ft  to 10 ft at the N and S walls with about 18" of overhang all the way around. I'd like to do clerestory windows at the N and S walls right under the roofline.
Where I'm stuck is how to tie the roof into the rest of the structure using, if at all possible, dimensional lumber (#2 yellow pine) alone.

So far, it seems the solution is to run a beam E/W and tie the rafters into it at the roof valley.  

So, at long last, my main questions are:

1) Can I forego ceiling joists with a low-sloped, v-shaped roof like this? (I've seen several smaller (like 14X14), low pitch roof structures that had no ceiling joists and would prefer to have the light from the clerestory windows not be blocked by ceiling joists.)

2) If I must use ceiling joists, can I use big enough lumber (2X10's or 2X12's) that the rafters can just sit on the ceiling joists?

3) If I do need a 20ft E/W beam, what size dimensional lumber might work if I support it at the 10 ft point with something like a 4" metal pole?

Thanks very much for any guidance you can give me.


Hi Mike,
Sorry I never got around to answering your question. I sketched out options for you several times, but unfortunately I was so busy with a new job and had recently moved to Australia at that time. I was really interested in your project, I hope you managed to get it completed, how did it turn out?

As I said, I am genuinely sorry, it was a very interesting project to discuss.
With Regards


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Brendan Cotter


Domestic extensions, planning permissions, house renovations, using solar power, renovation, adding value to a property, getting a house that the client wants


Im a graduate architect, with a Bachelor of Architecture from DIT, Ireland. I have a number of years of experience as both a design architect and a site architect, and have brought domestic projects through from initial client meetings through planning to construction and to completion and handover

Bachelor of Architecture, Dublin Institute of Technology, Dublin, Ireland

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