Clerestory roof

[UcfSE]

What would be some concerns with this style roof in a moderate seismic region with high wind (US VI)? I'm thinking diaphragm irregularities and dealing with shear transfer, maybe some ductility issues with columns. I'm just looking for some ideas or advice on what to watch out for, feasibility, solutions or how you dealt with something similar.

 

[csd72]

A few points:

Vertical push/pull reactions from overturning.

Concentrated horizontal reactions at the point of the diaphragm penetration.

Of ten they want to have windows all around so you have to have cantilevered posts to take the lateral load from the clerestory roof (think unresolved bending moments).

May be some local wind concentrations on the cladding also.

 

[jike]

Control your lateral deflections if you have windows around.

 

[UcfSE]

Thanks for the replies.

What I was looking at was a truss framed with a clerestory on one side like so: pic

My concern was how the diaphragm would behave and how that would affect seismic response and calculations, but I wanted to get some opinions on this.

Thanks again.

 

[haynewp]

I designed a similar looking roof years ago but we used steel joists and beams instead of trusses. I designed the edge angle along the top of the clerestory as the chord for that side of the diaphragm, and the continuous angle along where the clerestory attached to the lower roof as the chord for the right side of the diaphragm in your picture. Then designed the roof attachments for the 2 separate diaphragms. Concentric frames at interior and exterior locations, SDC C.

I figure this is steel and not wood since you mention column ductility. Are the lateral supports around the perimeter or at the interior also?

 

[UcfSE]

All I have right now is a rendering showing different views from an aerial position, so no plans, details or proper elevations. This project is in the very early stage.

 

[csd72]

Oh, that is different to what I pictured. I was thinking of a box shaped object sitting on a flat roof! All my comments above are based on that.

Where I come from, what you show is called a skylight and not a clerestory.

 

[apsix]

" box shaped object sitting on a flat roof" also known as a roof lantern (subject to regional variation).

 

[csd72]

Apsix,

Yes I have heard them called that as well.