OSB or Ply?

[Richard_C]

We need to quickly (as in tomorrow) build a ramp to get large but not very heavy wheeled musical instruments - timpani mainly - into a Transit. As cheaply as possible, appearance unimportant, this is a rough and ready job. We have angle iron from an old bed frame, so the simple plan is to use that for the long edges and drop a sheet of something into the "L" on each side, use an adhesive gloop and screw through from the bottom. The angle iron has a 40mm ish depth so with a 12mm sheet there will be enough upstand to stop casters running off the edge.

The ramp will be 1200 long and 600 wide. It won't be left outdoors. You do need to put one foot (and some weight) on the ramp as you push instruments up.

The local builders merchants has 11 mm OSB and 12mm Elliotis ply in stock, the OSB being much cheaper. OSB should be strong enough, but I have never used it in a project before. My thinking is that its good enough for my shed floor. Any thoughts on OSB vs cheap ply?

 

[Bingy man]

I’d rather put my faith into or in your case onto ply , only you will know the weight involved eg those loading it and gear combined-600 mm wide and 1.2 m long will I imagine flex quite a bit in the middle . Myself I’d be looking at 18 mm ply if it will be used on a regular basis or if using the 12 mm then consider a third support in the middle making a 300mm span max . Cost is one thing but a broken ankle or leg hurts more ..

 

[Spectric]

Why not just use scaffold boards, they take a lot of weight.

 

[Richard_C]

Looks like ply then, might engineer some lateral supports if it seems to flex. I had thought of scaffold boards but timpani have three smallish wheels in a tricycle arrangement so you need a wide flat smooth surface. If it all seems a bit flakey after it's been used this week I will do a redesign when I have a bit more time. Thanks.

 

[Jameshow]

A

Why not just use scaffold boards, they take a lot of weight.

3.9m length scaffold board could be cut into three 1.3m lengths and screwed together with some 2x2? Useful afterwards too.

Also proper angle iron is a pig to drill btw.

 

[profchris]

A

3.9m length scaffold board could be cut into three 1.3m lengths and screwed together with some 2x2? Useful afterwards too.

Also proper angle iron is a pig to drill btw.

From memory timpani wheels are more like casters, so might jam at the joins. But some hardboard or 3/8 hardwood ply on top would give you a smooth surface to run on.

The scaffold board idea seems easiest to do and cheapest, so I'd go for that.

 

[Limey Lurker]

A

3.9m length scaffold board could be cut into three 1.3m lengths and screwed together with some 2x2? Useful afterwards too.

Also proper angle iron is a pig to drill btw.

Old bedstead angle iron is high-tensile steel, and can be difficult to drill with hand held tools.

 

[trvlr]

If you go for either osb or ply of whatever whatever thickness... brace it underneath with something like 2x2 - preferably 3x2. Chopping up scaffold boards is a sin in the eyes of those who use them for their designed purpose... Also you"could insert metal strips between the sections where the board join; something T- shaped and maybe slightly convex, though flat would be equally fine. Key area to brace is of course where the boards abutt (join to one another); an extra thickness in that are would be useful (3x1 perhaps straddling the joint area across its length). That might reduce the need for "runners/braces" length wise. Although I'd be inclined have three of those - one on each edge and one in the centre, with the wider 3x1 between them straddling the joint.

 

[trvlr]

Agree the hardboard as single sheet coverage over the boards would give a very smooth surface and obviate the need for anything to cover the joints in any multi board design.