Hi Michael:

?

This looks like a great project. I note that the main thrust of your post is about board product selection, which I can’t help you with as I’m based in Australia. However, there are some similarities to your project with a solid wood library fit-out I did in 2016 and thought perhaps I could provide some inspiration.

?

Some feedback on your description:

?

Half inch back

I would increase this to a 3/4” back. Half inch does not allow for reliable rebate + glue + screw from the case sides, nor does it provide a “life-time” robust back that will not bow, warp, separate (etc.) from the cabinet back over time. It looks clear that you will be installing your library units permanently (reference to building a base onsite, plus the ladder usually needs something that ain’t moving), which means you’ll want to level the base and install the case units plumb with a wall that will most certainly not be flat or plumb itself. This means you’ll have gaps (sometimes largish gaps) behind a significant portion of your installation. If the backs somehow delaminate from your case sides, there is no scope whatsoever for rectifications. I would not want to take such a risk with 1/2” material.

?

Adjustable shelves

Adjustable shelves are nice, but I would counsel against them for a library of this size. Fixed shelving makes each case unit much stronger, and the fact that you can nail/screw the back into each shelf is a bonus. The library I did was only 2850mm high, so not quite as tall as your project but mine had an aggregate width much wider than your 18’. For a library of this size, in my opinion, complete freedom to arrange books with maximum flexibility is most desirable. Yes you’ll pack in more books if you size shelving exactly for novels, and shelving for a reference collection, but I’d rather miss out on a little saving of space for the flexibility of arranging books in whatever way you or the client wants. I tried to counsel my client to have a very large shelf at the bottom (350-400mm tall) but it was rejected for a uniform 300mm spacing between all shelving. I’d be happy to share detailed plans with you offsite if that is helpful.

?

Unit widths

You don’t reference the width of your units, but I suspect they are much wider than I would typically recommend. I have found that even with a substantial stiffener, unsupported shelving spans of more than 900mm always sag without steel reinforcement. I have made dozens of bookcases over the decades, from 1200mm, 900mm, 800mm, 700mm, and 600mm widths. You probably have too and I don’t mean to sh4t on your own experiences. For bookcases which absolutely must have wider shelves, I incorporate an upright which is housed into the front of each shelf, directly behind the two doors. This upright still allows books to stack on the shelves unbroken (behind the upright), and said upright is invisible when the doors are closed. This upright can be installed with fixed or movable shelving. For the 2016 library, I settled on 600mm widths. This was narrower than the client wanted, but the shelves exhibit minimal sag year after year. Something to consider.

?

Unit depths

Again, I know you didn’t ask, so forgive me for answering the unasked questions (David B. knows I specialise in these sorts of answers! LOL), but most designers (not necessarily you) make bookcases which are too deep. Almost all books fit on a 200mm or 8” depth shelf. Yes, there are some that require 220mm or more, but these are fairly rare. Now most bookcases are 300mm deep because the designer is working towards a “one size fit all” solution, and also because most bookcases are freestanding and need a wider (deeper) base. In your case, with fixed units, you have more choice to reduce the depth of your unit. 200mm would be radical. For my client, I chose a unit depth of 250 and a shelf depth of 210mm (with a 20mm back) which was perfect (IMO). That said, your shelves have doors (mine did not) so there is no scope for the odd book “sticking out”. In such a case, a 300mm deep unit might be warranted, less 20mm for doors, less 20mm for backs, for an overall shelf depth of 260mm.

?

Ladder

My library also had a ladder and great care is needed to make sure there is sufficient strength and space for a horizontal sliding rail (unless your ladder is an independent A-frame)? I can visualise a horizontal rail at the 2/3rds level (from the floor), more or less aligned with the solid “mezzanine” shelf on the right of your rendering? I would be happy to explore this further if relevant including pictures of my bespoke ladder.

?

Assembling units onsite

Looking at your rendering, I see that you are making many units and “stacking” them together. Definitely the right way to go. But I would look very closely at how you plan to make the installation look like a single unit or a single installation. Very closely.

?

For example, right now you have rendered horizontal face frames which are full-width, with upright face frames captured between them. I would strongly reconsider as you will have end-grain butted up against end-grain, and it will very difficult to get this many frames aligned to your satisfaction. The render also shows a strongly horizontal emphasis – which may be exactly what you want? I would push you to consider vertical elements, preferably full length as a way of tying all the units together.

?

I made individual units which were flanked by hollow (constructed) columns, which might be more elaborate than you have time or space for. But you should at least consider a full-length panel to cover the ends of your unit so the entire upright looks like one. (Don’t forget to make it extra wide so you can scribe it into the wall for a seamless look.) If you take up this advice, you’ll have a double upright on the far left of your installation. That extra thickness can look fantastic, and fit in perfectly with your internal uprights (if you take up my option of full-length vertical elements covering case sides).

?

Currently, as you have rendered it – you have a single upright on the outer or left side of the installation, but double uprights between each unit (since each unit has its own upright). Instead: butt each case hard up against each other, and then apply (during installation) a prefinished full-length upright to cover the exposed edges. This will allow you to have uniform vertical elements, that are say 36mm wide, at the full left, and between units.

?

I used a very large crown stapler and urethane glue to secure each unit to each other. My units had machined rebates on the front edge, read to receive the full-length vertical elements. After installation, I glued and headless pinned the vertical face frames for a seamless look.

?

If you like, I’d be happy to take this discussion offsite and share more details. I have no vested interest whatsoever except to be helpful. Take what is helpful and ditch the rest! ? Pictures to follow.

?

Before

?

?

After

?

?

Vertical Upright Detail

?

?

Sequence of shots showing the installation of units, crown staples, and installation of uprights in machined rebates…

?

?

?

?

?

Dr David Luckensmeyer

?