I’m fitting out a small room to be an office. I’d like a desk along one wall and want to mount it.

Battens is the accepted norm it seems, but could I use gallow brackets upside down so they’re a bit of a feature? Or is that daft?

I wouldn’t expect upside-down gallows brackets to be as strong as the upper fixings would pull out more easily? Could look cool though….

Geometry is the same up or down so the leverage us the same.

The bracket itself is potentially slightly stronger upside down as it removes the potential of buckling. I guess how it joins the brace on to the l bracket might need considering but assuming its welded i’d say crack on.

Edit: actually what you really do need to consider is how you affix the worktop. You are putting alot of pullout force on the threads you might be better to drill all the way through and bolt. Would look interesting and the brace will give you a nice book end to work with. Or they’ll get in the way…

Edit2: the comment about leverage isn’t true it is actually a worse case but decent fixing i wouldn’t worry about it. Just don’t stand on it.

have the brackets not usually got 2 holes at the top of the bracket (to double strength of pulling action also screws on shelf are only for holding shelf in place the right way round)

If they are on top the action of the bracket is to pull the wall fixings out. Mounted underneath they push against the wall. You could fit some on top as well just for appearance if you like them.

What kind of brackets?

I used some steel heavy duty shelf brackets from Screwfix upside down over an up and over garage door to hold boxes of stuff, fairly heavy.

I didn’t die.

Batten it for structural integrity and add the brackets as a cosmetic feature?

Is the worktop proper wood? If you just screwed it into MDF upside-down the screws would just tear out as soon as you put any serious load on it. Maybe put a metal strip underneath the worktop and bolt rather than screw?

What’s on the shelf?

I did upside down to use the diagonal as a bookend.

I think what people are saying is you want them underneath the right way up AND on top upside down, bolted together. Of course your house might fall down.