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

[postie101]

@MitchellMc So things are going well for the most part - I'm fighting against some fairly uneven brick walls though.

Can't blame this one on that though, accidentallyput one of my brackets up out of level. Doh.

Is this an acceptable solution? I'd be placing the ply shelf on top of those to level things out, and then screwing through the hole into the washer into the wood. I'm not sure about the structural validity of this approach though. I'm basically reducing the contact area between ply and bracket significantly.

Is that an issue and if yes, is there a better approach? Cheers.

[EricL]

Hi @postie101 

I don't think it will be an issue as long as the timber shelf is properly anchored to the angle bracket. Since you won't be putting anything extremely heavy at the very top, the shelf should be fine. I recommend putting the empty luggage and other small items at the top so that it will not put a lot of stress on the shelf or bracket. 

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

If you need further assistance, please let us know.

Eric

[Nailbag]

Hi @postie101 

I wouldn't be worried with that shelf being out a few mm off-level. It's very easy to do when drilling into brick as standard masonry drill bits have a habit of walking off the mark as you start the hole. And never trust that the brick's are level either if you're using them as your horizontal guide.

Using those washers as spacers to compensate for the variances in the brick facings is fine. But before tightening the screws fully, let the washers hang of the screw, not held centrally. Since the washer hole will be much larger in diameter than the screw, it will have the potential for the shelf to drop those few mm. For extra fastening strength, you could make the centre of the brick below then on the bracket. remove it and drill a hole a size the screw can slip through. Then mark and make another fastening hole in the brick.

I can't tell by this photo if you're using "stayed" brackets. This a much stronger than once that don't have an angled support arm. They come in a large range of configurations, sizes and colour.

Nairbag

[Dave-1]

Morning @postie101 

Nice way to gain some space back  

I do have a question about the bracket and teh way you have attached it to the wall tho.

What type of bracket are you using? If its the stayed bracket as @Nailbag had suggested then it should carry the load.

Im not  keen on the rawl plug and screw that you have used tho. It would hold a shelf yes but not a mezzanine floor (Unless I have it wrong and you are just putting an extra shelf in?) I lile concrete screws (they go into brick very nicely) and I find they give a lot more support and last a lot longer. I havnt had one fail yet or even split a brick. The holes on the bracket would need to be larger is all.

Ramset 8 x 60mm Galvanised AnkaScrew Masonry Anchor  just to show the type of screw I am meaning.

Dave

[postie101]

Hi mate, thanks much for your reply. That definitely has been my experience, I certainly underestimated how much variance the bricks would have in them and how much that would pass on to the bracket being square to the wall and level. Still fit for purpose (I’ll post some photos when all done), but it annoys the perfectionist in me.

So basically dont worry about trying to get the screw centrally in the washer, just let it sit up next to the metal?

Also I’m not quite sure I follow your tips about getting some extra fastening strength - are you talking about the washers on the wall face or the ones going on top of the bracket?

And yep, I am indeed using stayed brackets, linked previously in the thread.

Cheers,

Lachlan

[postie101]

Hi Dave,

Original plan was to put in a mezzanine floor, but in previous discussions ended up deciding to put shelving in around three sides of the perimeter of the room, leaving a gap in the middle for access. It’s actually a much more sensible idea, I’m glad I went with this approach.

Yes, I’m using stayed brackets (linked earlier in thread), and I’m using flat head 6mmx75mm dynabolts for the fixings (also linked earlier) - no plugs. I did also consider the ankascrew type - unfortunately these brackets have quite small 6mm holes for the fixings, so it’s quite limiting in what you can use. I think I did look and couldn’t find any suitable screw type fixings to fit. I guess i could have drilled the bracket fixing holes out a bit though.

Washer approach for levelling look fine to you?

Cheers

[Dave-1]

Morning @postie101 

Ahhh bingo makes more sense now. I must have misse dit in the thread. Yes the washer levelling is also what I would do (and have done so for one of my walls) I do like @Nailbag's explanation about letting the washers rest on the screw instead of holding them centered. Much easier instal and long term makes sense as well.

I think the extra fastening strenth @Nailbag is mentioning is to drill another hole in the bracket that matches the middle of the brick it is against and then add another screw to hold the bracket.

Dave