MDF Sagu-Mare Shelves

[rideforever]

I've got a load of old sag going on, I blame it on all those diy programmes in the 90s.
They are 1.5 cm x 105 cm x 24 cm, attached only at the ends usually are half full of books, or lipstick and hairdryers if you know what I mean.
Can someone recommend the best reasonably prices material ?
White Oak is £35 a shelf of something.
Birch Ply is cheap but is it any good ?
thanks for your criticism and recommendations !

 

[opps]

They look like 18mm shelves. *edit- yeah, they might be 16mm contiboard.

In the meantime, you could take them out and turn them upside down. A bit of an issue with the lower shelf because of the notch. They will bow upwards initially, become level... and then sag down- rinse and repeat.

25mm would sag less, but will sag in time.

Ideally the shelves would have been screwed to the backboard, but...

A timber support along the underside would help to slow the rate of sag but will not prevent the inevitable gravitation creep.

Alternatively, you could fit vertical dividers in between each shelf to support them.