Adjustable shelves

[woodbloke66]

Andy, those shelves look to be about a metre or possibly a tad longer? It's a good looking bookcase and shelf arrangement, but I don't think for moi personally I could live with shelves with even that small amount of sag...it would irritate me beyond belief; nearly as bad as having a shelf on a wall that's not dead horizontal :twisted:

I'm coming round to the idea of using solid pine shelves, say 23mm thick, lipped all round with oak and then veneered both sides with 2mm bandsawn veneer, so total thickness would be around 27mm. I'd need to buy the pine in good time to let it dry or I could use quarter sawn, stack laminated boards which would be more stable but a bit of a 'faff' to make - Rob

 

[marcus]

Crikey it’s a while since I got a UK workshop email popping into my mailbox! Nice to see so many of you still chipping away.

FWIW I found that thick birch ply (long grain, obvs, with hardwood lipping glued with a spline) 7/8 or even 1” was very stiff and never visibly sagged in any shelf I used it for.

Absolutely no rule of thumb to offer though, I used it and it always did the job is all I can say. Not the cheapest option though....

 

[AndyT]

Andy, those shelves look to be about a metre or possibly a tad longer?

1180 mm Rob!

And as a diy grade woodworker, busy with a young family back then, my standards were not up to yours now!

 

[woodbloke66]

Andy, those shelves look to be about a metre or possibly a tad longer?

1180 mm Rob!

And as a diy grade woodworker, busy with a young family back then, my standards were not up to yours now!

Thanks Andy. I found the Sagulator last night very informative but as it's 'murrican, it's a bit tricky to work out some of their definitions of man made board material - Rob

 

[Demusss]

You could glue a strip across the front of the shelf which is thicker than the shelf. This would help prevent sagging.

Sent from my SM-G965F using Tapatalk

 

[MJP]

I'm a bookseller and twenty years ago I built a couple of dozen six foot tall bookshelves from 7" by 1" PAR pine.
30" wide shelves, screwed and glued into rebates in the side supports, no backing. The only protection against racking being a 3" wide kick strip below the bottom shelf.

These shelves have been filled with mainly hardback books (hefty technical stuff) for two decades and show no visible sag.

I think that 30" is about the limit before sag begins to show.

Martin.

 

[woodbloke66]

I'm a bookseller and twenty years ago I built a couple of dozen six foot tall bookshelves from 7" by 1" PAR pine.
30" wide shelves, screwed and glued into rebates in the side supports, no backing. The only protection against racking being a 3" wide kick strip below the bottom shelf.

These shelves have been filled with mainly hardback books (hefty technical stuff) for two decades and show no visible sag.

I think that 30" is about the limit before sag begins to show.

Martin.

That follows my train of thought. However, have a swift look at the Sagulator and punch in some numbers. You can, I reckon (not sure here) go to any reasonable length before sag is apparent, provided you choose an appropriate material with a commensurate thickness (which might include lippings) and select the load that the shelf is meant to carry - Rob