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I'm planning to make a bunch of shelves in-leu of a bookcase (see picture). Individual shelves will be attached by a small corner bracket to the wall and to two support posts approximately in the middle of each side.

The question is about support of support posts. Posts themselves are 2 glued 1x0.5 inch oak planks. The corner would be a glued lap joint reinforced by a metal corner (1.5 inches, 2 screws on a side) and attached to the studs with another corner. So basically this would form a rectangle with the studs. Shelves (from 1x10 or 1x12 pine, if I manage to get the stuff straight), will attach to both studs and support posts.

Will such a construction be rigid and hold up a reasonable weight? Is there any way I can reinforce this without visible cross-braces or extending down to the floor?

Thanks!

Edit:

I think I will just drop the posts down to the floor, judging from the other shelves in the house the load on the shelves will be "pile it on until there is no more space". Really those posts should be from metal pipes...

Hungarian shelves is a great alternative that I'll definitely build elsewhere.

enter image description here

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  • With the large number of individual brackets you propose using I think this design could work but it's hard to be sure, but you may only be able to find out empirically — by building it and seeing if it holds up! Books are heavy, it's the reason so many traditional designs for bookshelves are so beefy. There's a load of levering force being put into each of those wall attachment points and as previous Questions have brought to light, the rough figures online for book weight per foot can be off by quite a bit — many of my paperbacks are way heavier than the general estimates for example [contd]
    – Graphus
    Aug 24 at 8:03
  • ...and the picture gets worse for hardback novels and especially for any hardcover picture books or coffee table books if you're looking to house any of those. If you do intend to heavily stack your shelving with paperbacks (like two deep, double row as I usually store mine) and/or there's a significant number of hardbacks I would suggest a redesign. And literally the first thing I thought of when I saw the Sketchup image was 'shoulda gone with "Hungarian shelves" ' :-) Simpler to build, cheaper and proven weight-carrying capacity.
    – Graphus
    Aug 24 at 8:10
  • Oh, thanks for the pointer for hungarian shelves, those look nice!
    – Eugene
    Aug 24 at 15:04
  • Would you define what you mean by "support beams"? Usually a "beam" runs horizontally, while a "post" runs vertically. In your drawing, I see what I would call 4 posts, supporting a bunch of shelves, but I see nothing that I would call a "beam". I'm sure it's just a terminology thing, so I'm looking for clarification.
    – FreeMan
    Aug 24 at 17:09
  • While you specifically ask about the support beams, the exact manner they connect to the vertical supports is critical. An enlarged sketch of this connection would be helpful to understand how the load is transferred to the vertical supports. However, my first concern is how the vertical frames are constructed including the connection of the horizontal to vertical parts. IT is also critical to consider how these frames anchor to the wall. All of the book load must be transferred at the top and bottom corners and the top of entire frame will want to rotate away from the wall. Details needed
    – Ashlar
    Aug 24 at 17:26
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The design, as shown, will likely put way too much torque on the bottom and top joints of your vertical supports. Replace, or reinforce, the short return-to-the-wall piece at the bottom with a triangular piece.

enter image description here

EDIT: This answer assumes the horizontal pieces in question are simply fastened to the wall with, say, a long screw through the sheetrock and into the stud. If this is the case the estimated torque, based on the scale shown, from four shelves of books acting between the bottom edge of the short horizontal "return" and the sheetrock would be in the range of 3000 N! This could be eliminated by running these returns into the wall and scabbing them to the studs, probably beyond the scope of the project. But even then there would still be about 300 N acting to bend that member. Making it thicker in the vertical dimension could compensate for this.

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  • Kudos for providing not one but two alternatives to add strength (although the left could do with being underneath the post, not behind it if you seek to avoid joint stress). But, I think you're overstating things when you say the design as shown WILL put way too much torque on the bottom and top joints. While I share the concern, we can't know this; so shouldn't state it as a fact. I'm very much put in mind of some modern chairs which look too spindly to survive yet apparently can take >100kg without flinching, e.g. the Conoid Chair, but even more so, this.
    – Graphus
    Aug 25 at 6:44
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Yeah, so 'bpedit' had a great suggestion (I would only use the design on the right hand side, the left side will have issues with the force transfer, and put undue stress on the fixing {whether glue, screws, nails etc.}).

I would note that the question is quite open-ended, so it's pretty hard to answer.

Taking a general approach to how the forces are applied is probably the best place to start.

Starting with the vertical columns; at the top of the column, you would expect an outward (away from the wall) force, this means the join at this point should cater for that. My suggestion is to have a screw coming from the top, through the horizontal support into the column, this should reduce the likelihood of the column slipping away from the wall at the top.

Looking at the bottom of the column, I would agree with the previous answer by 'bpedit', you need to transfer the force downward, and toward the wall, the easiest way to achieve this is to have a triangular piece. Worth noting that if you know all the weights and angles, you can work out the ideal angle for the triangle piece. Alternatively, you could use a horizontal and vertical piece, however this would not work with your design. Or you could even consider keeping the original design, and perhaps increase the thickness of the bottom horizontal beam in the vertical axis (the torque applied on the bottom beam is the most concerning part).

Again, the design will be mainly impacted by the design weight of the shelving.

Full disclosure, I am not an engineer. However I did complete 3 years of a civil engineering degree, completing all relevant structural components. If you have a decent handle on maths, I would encourage you to just do the calculations to find the forces applied in various areas, and adjust the sizes of wood and design etc. appropriately. Alternatively, just do it by intuition, though this may not work for everyone (and certainly won't work when you are looking at complex structures, this structure is not complex though, so should be safe). My main advice, is, think about how the forces would be applied at each area, and then design joins with this in mind. I.e. for the bottom section, you want the column sitting on top of something to transfer the downward force, and something sitting against the column (on the wall side) to also transfer the inward forces, this way the torque applied should be reduced, and the design safer.

Hope this helps a bit.

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