How to DIY a weightlifting platform and which type of plywood to buy?

[bilcruise]

Hi,

I am thinking to build a weightlifting platform for my garage gym, something like this.

As you can see the bottom layer is built by about 2 x plywood.

I went to bunnings website and not sure which plywood to purchase. The thickness is also a bit strange, I couldn't find one that is an integer number, e.g. 10mm or 20mm or something. The reason is that I want to put a rubber gym mat on the sides, just like the one in the photo and usually the rubber gym mat has a thickness of 10 or 15mm.

Any advice on this?

Also, would like some suggestion on which drill I should purchase to put screws on the plywood.

Thanks a lot!

[bilcruise]

By the way, this link does not work - https://www.bunnings.com.au/stanley-retractable-knife_p0203907.

[MitchellMc]

Hi @bilcruise,

Many thanks for your feedback on that link. I'll pass the details onto our team to look into. Here's an alternate link to our range of suitable Stanley Knife's.

We do sell Oriented Strand Board (OSB), but it sounds like @EricL's recommendation still lies with a material that has a solid timber skin coating like plywood. OSB, as with MDF, is a glued together material that can be susceptible to moisture and excessive wear and tear.

Please let us know if you have any questions.

Mitchell

[bilcruise]

Hi @MitchellMc , thank you. I actually went to Bunnings to take a look at your structural plywood the other day. I noticed the surface is rough and not sanded. It may be a dumb question but what is the easiest way to make it smooth?

[MitchellMc]

@bilcruise,

The budget structural ply is generally used for construction purposes and isn't necessarily finished smoothly. Coating it with something like Cabot's 1L Cabothane Clear Satin CFP Floor Polyurethane would smooth it out to a certain extent or, alternatively, an orbital sander would make quick work of it. You'll find smoother ply in our premium range, though there is also a significant price difference.

Mitchell

[bilcruise]

Thanks @MitchellMc , i just remembered @EricL suggested that premium grade plywood. i took a look again and realised the width is quite short, ~ 800-900 mm, whereas the structural plywood for the base has a width of 1200 mm. You guys don't sell custom sizes for those plywoods, do you?

For the orbital sander, would it do the job for the structural plywood? Or do I still need to coat it with that polyurethane after sanding it?

[MitchellMc]

@bilcruise,

We have 2440 x 1220 x 12mm AA Grade Mixed Hardwood Marine Plywood which has an exceptionally smooth finish.

The orbital sander has the ability to create a very smooth surface; it just depends on how smooth you want it. It would be worth considering whether the structural ply, sander and coating would cost you more than just purchasing the Marine grade ply I've linked to above.

Mitchell

[TedBear]

Hi @bilcruise , I am wondering why the ply needs to be smooth? The recommended method only has ply for the under base, which doesn't need smoothness. If you use a piece of MDF for the centre platform that you stand on,  the structural ply underneath would be fine. (My apologies if I have misunderstood your current plans.)

[bilcruise]

Hey guys, just another question I forgot to ask. Do you think the combination of plywood + the dense rubber gym mat (weightlifting platform) is enough to protect my porcelain tiled floor (underneath the tiles is concrete slab)? I'll be doing weightlifting so some good amount of weight will be constantly dropped onto it.

[MitchellMc]

@bilcruise, 

Not if you're dropping weights from waist height as is sometimes needed. It's a bit hard to tell. If they are older solid porcelain tiles with no air pockets under them, they might be fine, but I don't think I'd be comfortable in saying you won't see them crack.

Mitchell

[bilcruise]

Yeah that's fair enough. it's difficult to tell without trying it, which may not be a good idea Some folks suggested the following combo: EVA rubber mat, plywood then finally the rubber gym mat. But again, can't say unless you try it. This is the tile at my garage - https://www.tfo.com.au/product/luxor-grey-honed-concrete-look-rectified-porcelain-tile-3496/#/dfcomp.... Doesn't say whether it has air pockets or not.