I guess anybody could tear out their ceilings, move the plumbing and wiring to a non-exposed area and then install the shelves. It doesn’t seem worth it, though.

Oh, and don’t try this if your home is fancy enough to have a sprinkler fire system. You’d be placing all the combustibles in a (very hot) location inaccessible to your sprinkler!

Takuan, cross-bracing isn’t always necessary, especially with joists of ten inches or less.

I’m only keeping reference books and books that I use to study. All other books are put on the give one/take one shelf at the library and I vowed to only use the library for fiction and political non-fiction.

It’s been great and my apartment is not as cluttered and when I move this year, I won’t be lugging a lot of books!

/It helps to live a few blocks away from one the best public libraries in the world, though. HA!

http://www.flickr.com/photos/fyngyrz/582936293/

…we keep most of our paperback SF up there.

Use of artificial i-beams (BCI’s) at close spacing and without the requirement of supporting anything other than furniture overhead pretty much eliminates any concerns of overloading the beams.

I take that back – all rooms with a floor or roof above the occupied space have joists or rafters of some sort.

“Hey! Get back to your video game and Big Mac, Junior!”

I would be careful for 3 reasons:
1) Additional load — Book storage is quite heavy. One of the heaviest load patterns in structural engineering is for library loads, due to the book storage.
2) Earthquake hazards
3) Creep — Sustained loads on timber structures slowly make them permanently deform. You don’t want to have a bunch of sagging joists and a sagging floor above.

(By the way, I don’t think the members that you refer to are rafters. Rafters are used to create a pitch on a roof. I think you are looking at using joists, but no one will care unless you’re an engineer or an architect.)

Also, take care in designing the connection. From the picture, it looks like you’re nailing or screwing through the bottom of the shelf board into the bottom of the joist. This could wreck your joist if you split it and could help the pull-out of the nails since you’ve put them in tension. A better connection detail would put the nails or screws in shear, having the nails or screws come into the joints horizontally from the side.

They will roll if not braced, the shelving visible helps slightly but the overall appearance is not good.

I suppose the planking used as shelving may have been intended as bracing – with the upper mezzanine only intended for light storage.

What’s upstairs?

My father came up against this problem while I was in high school. When we moved into our newly-built house, he put most of his considerable library against the interior walls of a 2nd-floor room, and didn’t think anything of it for three or four years.

Then one night, I’d just gotten home when I heard a loud squawk and the sound of his shoes pounding up and down the stairs. When I went to find out what was going on, I found him frantically stacking piles of books against exterior walls and bringing them downstairs. It turns out that he’d been rehanging the door on the 1st-floor bathroom for the 2nd or third time that year when it finally struck him that whole side of the house was sinking into the basement.

We learned after the fact that our builder may have cut a few corners securing joists, but that just accelerated the progress from a span of decades to a span of years.