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brownmoose 04-27-2010 10:39 AM

supporting large bookcase
I am looking to build a large bookcase. Approx 10' long by 10' tall with a desk at the bottom. Problem is that it runs along a floor joist, not across. This means that if I do not find some way to support it then the entire load will be resting on a single floor joist. I'm just afraid that this will lead to a failure. I'm open to any recommendations and have even considered putting a new beam above the bookcase (16' wide row home) and suspending the bookcase from the beam but that would be a lot of work and I would love some other suggestions. BTW - looking to keep a classic look so a hanging wire bookcase is out of the question unless wire can be concealed with wood.

BTW - I don't have access to the floor beneath it - would require a lot of work cutting ducts and such to sister the joist.

jogr 04-27-2010 09:12 PM

How much do you think it would weigh loaded with books? Off hand, I'm thinking it shouldn't be a problem if your floor is rated to current standards (40 psf live load).

oh'mike 04-27-2010 11:07 PM

I'm with jogr --The floor should take that--However, I would think that you would also be transferring a fair bit of the weight to the walls,also.

There will also be screws holding this to the wall ,right? That portion of the weight will be removed from that joist.


Scuba_Dave 04-27-2010 11:21 PM

A 10' tall book case is pretty tall, how many shelves ?
If each shelf is 12" tall that can be 10 shelves ?
So 12" x 12" base then going up 10' = 10 shelves

If each 12x12 area holds even 5 lbs of books thats 50 lbs psf
If each holds 10 lbs that's 100 lbs psf
Take some books that fit into a 12x12 area & weigh them

And then you are loading the joist for a 10' length
That's quite a bit of possible weight

I would locate the studs & put shelf brackets in so that the wall holds the majority of the weight

brownmoose 04-28-2010 10:58 AM

The walls are just sitting on the joist - not exterior walls and no interior walls are load bearing. All joists stretch directly from one exterior brick wall to the other. This is a 100 year old house so it's not a brick veneer - it's a solid brick wall on each side. This means that tying the bookcase to the wall will keep it from falling over but won't take the weight off of the joist as the joist already holds the weight of the wall - the more I think about this the more it sounds like I'm going to need some more support for it.

eisert 04-28-2010 02:59 PM

Keep in mind that floors are built as a system, not as individual joists. The bridging or lateral bracing helps distribute the weight to nearby joists, and the subfloor helps ditribute this even further.
