Expert: Dan Griffin - 11/15/2011

Question
I just bought a house (2,800 sf), built in 2001, in Fort Worth, TX.  I have a massive library of about 10,000 books and 40-45 bookcases, plus 14 filled file cabinets. I am filling three rooms upstairs with this weight, very compact. One room is over the garage (about 17 by 14) and there are two other rooms (about 14 by 16 and 12 by 15), plus a hallway. The question is: I keep finding books to put in those rooms. Is there any danger that the floor can't handle all of this weight (I guess some tons)?  I can't use the garage since that will be filled with cabinets and books as well. What should I do? Should I trust the floors?
Thank you so much. Richard

Answer
Richard, you are quite right to be concerned.  Code always used to require 40#/SF capacity, but newer limits have decreased some bedroom situations to 30#.  I don't know what you have, but books and paper storage can hit and exceed 100#/SF quickly.  I assume you are talking about arranging freestanding book shelves a bit like a library.  Code requires library stack areas be designed for 125#/SF, using book weight at about 65# per cubic foot.

I don't know how to advise you as I don't know how you intend to arrange the books, store the books, or how high the book cases are.  Floors tend to be stronger near the walls, you create more bending of joists out in the middle of the floor, though not all walls are load bearing.

YOu might be well advised to have a structural engineer or good builder look at your actual arrangement and circumstances.  I cannot just say to go ahead and fill the rooms up.