Long span shelving – support material

[PuddleglumParticipant @puddleglum]

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.

[PuddleglumParticipant @puddleglum]

[Pete RimmerParticipant @peterimmer30576]

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.

[PuddleglumParticipant @puddleglum]

Posted by Pete Rimmer on 29/05/2023 17:11:07:

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.

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

[Nicholas FarrParticipant @nicholasfarr14254]

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.

[Maurice TaylorParticipant @mauricetaylor82093]

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

Maurice

[DiogenesIIParticipant @diogenesii]

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

[PuddleglumParticipant @puddleglum]

Posted by Maurice Taylor on 29/05/2023 17:49:21:

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

Maurice

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

[PuddleglumParticipant @puddleglum]

Posted by DiogenesII on 29/05/2023 17:50:49:

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

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

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

[PuddleglumParticipant @puddleglum]

Posted by Pete Rimmer on 29/05/2023 17:11:07:

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

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

[PuddleglumParticipant @puddleglum]

Posted by Nicholas Farr on 29/05/2023 17:36:39:

3 metres is quite a wide span for anything without a bit of depth to it

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.

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

[Pete RimmerParticipant @peterimmer30576]

Posted by Puddleglum on 29/05/2023 18:03:03:

Posted by Pete Rimmer on 29/05/2023 17:11:07:

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

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

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.

[PuddleglumParticipant @puddleglum]

Posted by Pete Rimmer on 29/05/2023 18:16:06:

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

[Peter Cook 6Participant @petercook6]

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!

[Maurice TaylorParticipant @mauricetaylor82093]

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

[PuddleglumParticipant @puddleglum]

Posted by Peter Cook 6 on 29/05/2023 18:50:56:

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!

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…?

[PuddleglumParticipant @puddleglum]

Posted by Maurice Taylor on 29/05/2023 19:08:29:

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

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

[DC31kParticipant @dc31k]

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.

—

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

—

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.

[John Doe 2Participant @johndoe2]

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

[JAParticipant @ja]

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

[martin haysomParticipant @martinhaysom48469]

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

[PuddleglumParticipant @puddleglum]

Posted by JA on 29/05/2023 20:22:10:

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

Worry not – step ladder. It's for the stuff that is in the "I don't often need it, but I will probably need it in future" category.

[PuddleglumParticipant @puddleglum]

Posted by martin haysom on 29/05/2023 20:39:22:

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

Yes, minimum of 2, maybe 3 or 4. Working out what the minimum needed would be.

[Mike LondonParticipant @mikelondon]

Have you considered "Dexion"?

Deep angle section without the weight. For extra strength bolt two lengths together back to back to create "T" section.

Can be found second hand quite cheaply, from various sources. I use it all over the workshop.

[John Doe 2Participant @johndoe2]

You could go for 4 supports but I would advise that you go for 5, which would mean you would never need to worry about overloading, nor about the shelf sagging between the supports.

Assuming an inset of 20mm from each end; the shelf support centres will need to be at;

20mm

760mm

1500mm

2240mm

2980mm

As measured from one end

[Author]

Posts