Very wide alcove shelves

[burritofan]

Typical 3-bed Victorian terrace with the front two rooms knocked together by previous owner, to make one long room with two chimney breasts. They haven't left any upright wall between the two chimney breasts to use as support for putting in alcove shelving.

Consequently the middle alcove is 202cm wide – we can get planks to fit and we were planning on DIYing basic baton + plank type shelves, with batons on each side (against the chimney breasts) and a long one at the back.

But will they be strong enough to hold (a lot of) books or do we need to think about putting something upright in the centre to prevent sagging? Or opting for thicker wood (fnar)?

We had this and did batons all the way around the sides and back otherwise it wasn't storng enough in the middle.

Thanks – we're planning on a long support at the back, as sturdy a bit of wood as we can. Did you find that was enough to support a full shelf of books?

We have normal width shelves in our Victorian house as the rooms haven’t been knocked together but the shelves are made from scaffolding plank and look pretty good ( previous owners made them). I’d have thought that if the wood for the shelf was thick enough it shouldn’t need middle support?

A framework of 2x1 wood, with cross braces at intervals, secured to three walls with long fixings would give enough support. I did this for a platform bed for my son and it was enough to hold him as a teenager! You'd only need thin ply or MDF on top (and underneath if you want to hide the supports) and you'd have lovely chunky shelves.

There are guides
www.popularwoodworking.com/projects/aw-extra-3614-stronger-shelves/

www.thespruce.com/recommended-shelf-spans-and-spacing-1824823

Oh, brilliant – thanks everyone! You've set my mind at ease that we can do this without bringing everything tumbling down. Those links are great, AND have replenished my supply of "firm wood"-type single entendres with which to entertain DP while he holds the spirit level and I go "Mmm, up a bit more?"