Long span shelving - support material

Hi,

Not model engineering, but hopefully there are folks with experience \ knowledge that can help...

I have a space above my garage door that I'd like to use as a storage area. To do so, I need to run shelf supports across the 3 meter width of the garage.

My initial thought was box section mild steel... I imagine that I'd need something rather beefy - but can't decide just how beefy.

Then, having thought about box section, started thinking about rusting from the inside out - so maybe angle iron that I can paint is a better option. Found some that is 40mm x 20mm x 4mm thick - but is this too wimpy?

Was thinking 3 supports - front, back and centre. Load to bear - say 200kgs

Thoughts welcome.

4mm thick is miles too heavy. My high-level shelving is made from 40x40x1.6mm thick and it spans 2m+. It's loaded up to the nines with no sign of distress.

I've even made a rack to hold the working heads from my mill which are up to 50kg each. The rack is just short lengths of this same box section welded to the wall frame one end and they too seem to hold up with no issues.

Cool, thanks. I am prone to over-engineering \ over-thinking designs

Hi Puddleglum, 3 metres is quite a wide span for anything without a bit of depth to it, and a beefy bit of box section will be heavy, rust inside would be the least of you problem, but you can put those plastic bungs in the ends which would slow down the process. Lightweight rectangular section, say 80mm deep would be better, but better still would be to have a central support from the roof, if it's strong enough. Bearing in mind that the larger section you have, the more expensive it will be. 40mm x 20mm x 4mm would be OK if you made a Lattice type beam of a suitable deepth.

Regards Nick.

Hi , I think it would be easier for members to give answers if you put photos of location of shelf on.

Maurice

3m wide, but what's the front-to-back depth of the space?

Not really anything to show - 2 walls, 3m apart. To run a shelf across, will need support "beams" that span the 3m. As they'll only be supported at the ends, worried about deflection \ bending failure.

Edited By Puddleglum on 29/05/2023 18:00:26

That's kind of irrelevant... but about 600mm.

Edited By Puddleglum on 29/05/2023 18:00:45

Does this have supports in the middle, or just the ends?

Yep - it's a fair span. What got me thinking it might be possible was the pallet racking in warehouses. Like this. Doesn't say what the cross section dimensions are though

Unfortunately, not possible to add central support from roof
 

Edited By Puddleglum on 29/05/2023 18:18:55

Supported either end, cross-bars between the front and rear spans every couple of feet just to support the chipboard shelf.

If you want to know about deflection for 200kg load just get a piece of the steel, span it across and get two chunky people to hang on it in the middle.

Ah cool

It might come to actually testing - was hoping to avoid ending up with a bent 3m length of box \ rectangle that I haven't a use for

There are several free beam calculators on the internet that will let you do deflection calculations. You can test out various materials and cross sections without risking your box section - or the bodies you hang from it!

Hi,Have you considered using 4 x 2 timber ,I’d use 3 pieces of 4 x2 to span the garage and put a piece of 18mm plywood on the top of it . Cheaper and easier than steel.

Maurice

It might be I'm a bit thick - but the ones I found required all sorts of parameters I haven't a clue about. Unless you could kindly point me in the direction of a simple one...?

Yes, I considered 4x2s, and my gut feel is they'd deflect over time.

What is above the proposed shelving?

If there is a way to support it midspan, that will help a lot. Could be as simple as a piece of rope tied to the ridge timber.

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The 4" x 2" timber and plywood has a structural depth of over 100mm. That might be a consideration if headroom is limited.

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The 200kg person hanging on the middle will give a conservative over estimate of the deflection as the 200kg load is distributed evenly over the 3m x 0.6m area, and shared between more than one support.

I am having difficulty visualising this. For medium loads, I put supports every 700-800mm. and use 18mm thick plywood sheeting cut in strips.

My only comment is that the shelving will be rather high up. OK when you are young and middle aged. I now find all my high shelving, above 65", slightly difficult to reach. I put a shelf above one garage door and have not been there for years.

JA

could put more than one beam from side to side to increase load capacity