How do I engineer a floating mezzanine storage floor for my storeoom?

[postie101]

I've got this storeroom that's been added on to the house at some stage. The wall on the left is the original exterior wall, and I believe the construction is double brick all around.

The space is very small, so I'm looking to add a mezzanine floor for storage. It needs to be above head height - I'm imagining it going roughly where those existing boards up on the wall are, just needs to be big enough to storage storage bins, xmas tree, etc. Most of the stuff in photo would ideally end up being stored there, aside from lawn mowers of course. Would certainly need to be able to handle me climbing up there to grab stuff.

Since the space is so small, I'd really like to use a floating design - having a box frame would make things even more cramped. It's an old house, and none of the walls seem to be particularly plumb either, which I imagine would complicate things if trying to build in a frame.

The span would be just under 1.5m, and the platform would be just under 1.5m in depth also. The depth might end up being slightly increased (~1.75m), let me know if this changes things at all.

What timber / fixings should I be looking to use for this?
I've found this article, but not sure how reliable it is.
https://www.bhg.com.au/homes/diy/build-a-mezzanine-garage-storage/

A lot of the designs I've encountered are based off a stud wall - I've got masonry all around so want to make sure I'm doing things right.
Cheers 👍

[MitchellMc]

Moving from a 415mm to 550mm spacing would be negligible to their weight rating @postie101. Remember that's 250kg per bracket. If you have four brackets, that would be 1000kg spaced at 415mm centres. Even at 550mm centres, your brick wall would collapse before the brackets failed. You shouldn't be putting much more than 100 kg on the wall, as brick veneer walls are not designed to take side loads.

Those Dynabolts are exactly what you would use.

18mm ply or MDF would be the way to go as 12mm is too thin. I'd recommend cutting down sheets of CUSTOMwood 18 x 2400 x 1200mm Raw E0 MDF or SpecRite 2400 x 1200 x 17mm Film Faced Non Structural Plywood.

Mitchell

[postie101]

Great @MitchellMc. Just on the side load point - is the height at which I'm planning to mount these shelves acceptable? I count 8 courses of brick on the shortest wall (rear and left wall appear to have slightly more, sloped roof), above where I'd want to mount them. Is that enough for this purpose? I know more is preferable as they add weight to the brick holding the mountings which would reduce the chance of the brick getting pulled from the wall.

Potentially overthinking again as I would only have around 25kg-ish being held up between each bracket, but thought it would be worth asking.

[MitchellMc]

Hi @postie101,

I don't think it particularly matters too much where you put the shelves. Just don't go and load several hundred kilos on each shelf.

Mitchell