I'm thinking about making / having made some bookshelves to replace some flat-pack trash "book" shelves that can't really hold books.

A lot of my books are on the larger and heavier side. The most conservative estimate I've seen for linear weight of printed materials is 40 lb/ft. The shelves would be 30" wide and six high, so call it about 600 lbs of books plus another 200 lbs (conservative) for the actual shelf.

Critically, a) the shelves would have two "feet", about 1"×12" in size, and b) would be on an outside wall parallel to the joists. Also, the "feet" probably aren't resting directly on joists. Also, as there are multiple shelves, it's possible any single joist would see "up to" 800 lbs just from the shelves. (That load won't be directly over a joist, however; some should be shared with neighboring joists.)

Is this safe? (The house was built in 197x.)

  • 1
    If the legs are over joists by a wall, then maybe okay. Legs not over the joists will depend on the sub floor thickness, 197x might be a 1/2 inch. Having a nice stained 2x12 base for the legs to sit on, will not hurt.
    – crip659
    Commented May 16 at 21:35
  • @crip659, for... reasons... elevating them that much is likely problematical. What I probably could do is build "rafts" out of 1" (nominal) boards. Actually, as I'd forgotten I'd intended to put feet on them, which would significantly reduce the contact area, that might be a good idea, since I can then omit the feet.
    – Matthew
    Commented May 16 at 21:52

1 Answer 1


The 800 lbs would be shared between the 4 legs, so that isn't an issue unless you have a very poorly built home.

The issue I would have is danger if the shelf fell. It would be prudent to have it anchored to the wall in a couple of places near the top.

  • Imagine a heavy sofa with 4 legs and 3 big guys sitting on it. Not far off OP's design, in fact OP's may be less demanding because the 12 inch boards have no feet. Nobody would imagine that a normal house floor would not be able to support a sofa. I think "a very poorly built home" here is an understatement. Is it made of cheese cake? If it is please invite me. I'll help you with your book case. :) +1, and another if I could for wall anchoring.
    – jay613
    Commented May 17 at 17:18

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