How to Reinforce a Bookshelf or Storage Unit for Extra Strength
A struggling bookshelf is nearly always one of two problems, and it's worth working out which before you buy anything, because a shelf that bows in the middle needs a completely different fix from a whole unit that sways when you lean on it.
Shelves that sag in the middle
Books are heavier than they look, and a long span of particleboard or MDF under a row of hardcovers will creep downwards over time, where solid timber of the same thickness holds out a lot longer. Turning the shelf over so the bow faces up buys you some time, but I'd treat that as a stopgap rather than the fix.
The proper fix is a strip of timber glued and screwed along the underside of the front edge, which stiffens the board a lot for very little money. If the span is long you can also add an upright in the middle so the shelf isn't carrying the whole load in one go. We cut timber to length on the saw bench while you wait, so bring your measurements in with you.
A unit that sways from side to side
If the whole thing racks or leans when you push it, the back is usually the culprit. A lot of flat-pack units come with a thin backing panel held on by a few small nails, and that panel is the only thing keeping the box square. Screwing a sheet of ply onto the back instead, with the unit pushed square first, makes a big difference, and so does a small angle bracket in each top corner where the top meets the sides.
Swap out the weak screws
The little screws that come in the box are often the weak point, especially in particleboard, which strips easily. Chipboard screws are made for exactly that material, and where a hole has already stripped it's better to move the fixing over a little than to force a bigger screw into crumbled board.
Fix tall units to the wall
Any tall unit that's loaded up should be fixed to the wall, and that matters even more with kids or pets in the house who'll try climbing it. An angle bracket screwed into the top of the unit and into a wall stud is the strongest option. Where there's no stud behind the plasterboard you'll want a proper hollow wall anchor such as a spring toggle rather than a plastic plug.
When it isn't worth saving
If the sides themselves are swollen or crumbling at the joints, usually from getting wet at some point, I wouldn't spend money reinforcing it, because the fixings have nothing solid left to bite into.
Shop related products
- Zinc Plated Angle Bracket 50 x 50mm. For bracing the top corners or fixing the unit to the wall.
- Macsim 8-10 x 25mm Chipboard Screws. Made to hold in particleboard.
- Macsim Spring Toggle 3mm x 50mm. A hollow wall anchor for plasterboard with no stud behind it.
- Supercraft Level Torpedo. Small enough to check a shelf is sitting level.
Did you know we also keep shelf brackets and cabinet shelf supports in the shop, and they aren't all on the website. Give us a ring on (08) 8536 4333 to check what's on the shelf.
The fixings that are online sit in fasteners and fixings, and there's more general gear in hardware.
Read next
- How to choose anchors and screws for heavy items
- Drill or impact driver, which one do you need
- Essential tools every first time homeowner needs
I'd much rather screw a strip of timber under a shelf than pick a row of books up off the floor.
Candeece
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