How to make a LACK shelf carry 36kg without external brackets

I’ve always loved the clean look of a LACK shelf with its supporting bracket hidden inside. Problem was, you couldn’t really put much weight on it. Even with the solid brick walls that we have in Malaysia, the maximum load was 15kg & it had to be spread across its surface. I tried to put a 10kg speaker on one end of it & the load pulled the wall plugs out.

So, I hacked it using just a couple of steel anchor bolts & threaded rods through the hollow tubes of the bracket. If you don’t know what these are, have a look at the pics below, different hardware shops may have different names ie- drop-in anchors, endless screws, studs, screw rods, etc. Just tell them it’s the stuff used for hanging cartridge type air-conds from the ceiling!

Pic 1

The LACK shelves we get in Malaysia have this kind of brackets & this hack will only work with solid brick or concrete walls:

Pic 2

This hack will NOT work with the brackets for drywalls shown below:

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When I first did this hack 9 years ago, the tubes on the brackets were open on both ends. With the LACK shelf I bought recently, I had to drill out the inside hole to fit the 3/8” rods:

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The rods are usually sold in 6ft lengths so have to be cut to fit, I estimated about ¾” to fit into the anchor bolt in the wall & maybe half an inch to fit 2 nuts on the outside end:

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Make that 9 ¾ ” or slightly longer at 25cm if you prefer… I know, it’s kinda weird… in Malaysia, some hardware stuff are sold in Imperial units, others in Metric… so I use both!

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So long as it fits easily inside the shelf:

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Next, I marked & drilled the usual 6mm holes in the wall for the normal plastic wall plugs, with 2 additional 9mm or 10mm holes for the drop-in anchors:

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Use a 9mm drill bit if your wall is soft, 10mm if its hard concrete. Drill bits are sold here in mm but threaded rods & anchor bolts mostly in inches.. go figure!

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Screwed the rod into the anchor bolts by hand as far in as possible:

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Then put 2 nuts on the end of the rod:

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And locked them tight against each other:

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I could then seriously tighten the rod into the anchor by turning the OUTSIDE nut clockwise. If both screws are turning instead of the rod, you’ll need to lock them together tighter:

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After the rod had gone in as far as it could, I just unlocked the nuts by turning the INSIDE nut clockwise. If it’s locked too tight, just use 2 spanners instead:

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I removed the nuts, fit the bracket through over the rods & fastened the bracket with all the screws for the normal wall plugs first:

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I had to make sure I got just the right sized washers, they have to be bigger than the tubes to fit over them, yet smaller than the holes in the shelf to fit inside them. Use 2 or 3 washers if they’re the thin, flimsy type:

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This next step was THE crucial part. I tightened the nut as hard as I could, locking the bracket tight against the wall. I mean, it was locked rock solid, no give at all. This is important because it’s the tension that holds the weight, not the size or stiffness of the rod:

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Not absolutely necessary but I felt safer locking in a 2nd nut:

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Slid the shelf over the bracket & fastened it. It still looks exactly the same as a normal LACK shelf installation:

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BUT… it holds 24x 1.5litre bottles of water easily!

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That’s 36kg, about 80lbs just sitting there near the edge:

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LACK Shelf hacked by:

~ Bino Nga