Setting up a power cage platform, quick questions

[TheToolbox]

I am setting up a power cage platform over hardwood. My current idea: Drop cloth on the very bottom (size 6 by 8 feet), two pieces of plywood (4 by 6 feet each, or possibly one piece 6 by 8 -- not sure what's available yet), and two tractor supply company mats (4 by 6 feet each).

I have a few quick questions:

1. The tractor mats are heavy as hell. Will they be fine just being set side-by-side? Will they move at all even if I don't "fuse" them together in some way, via nails or clamps or whatever?

2. My power cage is not a bolt-down. Is it necessary to bolt/screw anything together in the platform?

3. Is a drop cloth going to be sufficient for the bottom layer? My intention here is to protect the hardwood from getting scratched by the plywood. The plywood is meant to prevent any rubber from melting/degassing into the floor and to help further distribute the load.

[KBKB]

I am setting up a power cage platform over hardwood. My current idea: Drop cloth on the very bottom (size 6 by 8 feet), two pieces of plywood (4 by 6 feet each, or possibly one piece 6 by 8 -- not sure what's available yet), and two tractor supply company mats (4 by 6 feet each).

Plywood is sold in 4 foot x 8 foot sheets. You can have the lumberyard cut it to 4x6, but I think it makes more sense to purchase two 4x8 sheets and have one of them cut to 2x8. (Use some mending plates on the edges to keep the two pieces together.)

I have a few quick questions:

1.The tractor mats are heavy as hell. Will they be fine just being set side-by-side? Will they move at all even if I don't "fuse" them together in some way, via nails or clamps or whatever?

I think you'd be best fastening the mats to the wood in some fashion, because I think it's likely that they'll shift somewhat. Maybe use some screws and washers at the edges and corners where weight won't likely get dropped. You probably won't need many of them - you need to secure it just well enough to prevent the mats from shifting.

Something like contact cement could also be used to glue the mats to the plywood. If you don't go nuts with it, you'll probably be able to peel it up from the wood if you ever want to disassemble it.

2. My power cage is not a bolt-down. Is it necessary to bolt/screw anything together in the platform?

It's not necessary, but stability will be improved. If you do it right, you could then use bands with the rack as well.

3. Is a drop cloth going to be sufficient for the bottom layer? My intention here is to protect the hardwood from getting scratched by the plywood. The plywood is meant to prevent any rubber from melting/degassing into the floor and to help further distribute the load.

Not sure, but I would say that it's better than putting plywood directly on top of the hardwood floor.

If the floor is perfectly flat, the plywood is not warped, and you're careful to not have any seams from the dropcloth between the wood and the floor, it'll probably be fine. But if one or more of these conditions are not met, some part of the hardwood floor will have considerably more pressure placed upon it than the other areas, which could potentially cause problems.

You might consider using a carpet pad (underlayment) between the plywood and your hardwood floor. It's squishier and might mitigate problems from having a much thinner layer of canvas between the two surfaces.

[cmarti063]

KBKB provides good info as usual. A few notes, stall mats won't melt and off-gas into your floor. That is a very irrational concern. Mats will move a little without being secured, even with tons (literally) of weight on them. You could simply forego the plywood, then you wouldn't need to worry so much about putting something under the plywood.

[TheToolbox]

KBKB: Thank you for the great advice.

I think you'd be best fastening the mats to the wood in some fashion, because I think it's likely that they'll shift somewhat. Maybe use some screws and washers at the edges and corners where weight won't likely get dropped. You probably won't need many of them - you need to secure it just well enough to prevent the mats from shifting.

I'm not great with this, but I do know the mats are .75 inches long.

According to windsorplywood.com/how-to-detail.aspx?id=1274 it seems as though plywood comes in varying thicknesses.

How thick should the plywood be, and how far down would I need to screw? (I'm guessing I'd need screws of length .75 + (thickness of plywood)/2 inches or so). I'm guessing .75 thickness for the plywood would probably be enough as well?

You might consider using a carpet pad (underlayment) between the plywood and your hardwood floor. It's squishier and might mitigate problems from having a much thinner layer of canvas between the two surfaces.

Ahhhh, this makes me wonder...

I do have a rug I was intending to get rid of (5 by 8)... I wonder if I could use this somehow. Would still be short a foot but it'd be near the edge of the platform anyway. Hmmm.

[TheToolbox]

KBKB provides good info as usual. A few notes, stall mats won't melt and off-gas into your floor. That is a very irrational concern. Mats will move a little without being secured, even with tons (literally) of weight on them. You could simply forego the plywood, then you wouldn't need to worry so much about putting something under the plywood.

Good to know, thanks. However, the mats do still have some grit to them, so I figure I'd still need some sort of protective layer. I feel like I'd also still need the plywood even if only to have a "hard" surface upon which the load can be distributed (as opposed to having the soft mats distributing the load down into the hardwood).

[KBKB]

I'm not great with this, but I do know the mats are .75 inches long.

According to windsorplywood.com/how-to-detail.aspx?id=1274 it seems as though plywood comes in varying thicknesses.

How thick should the plywood be, and how far down would I need to screw? (I'm guessing I'd need screws of length .75 + (thickness of plywood)/2 inches or so)

Use 3/4" plywood. Screws can be 1.5" long provided you use at least one washer with them. The thickness of the washer will prevent the screw from coming out the bottom of the plywood and marring your floor.

You might consider using two washers, one normal sized one on top and a fender washer just below it. (Fender washers have a much larger outside diameter than normal washers.)

If you use screws that are 1.5" long, you will want to take care to not compress the mat too much. Use of a fender washer will help to prevent this as you'll be attempting to compress a much larger area when driving the screw.

You can use a shorter screw, but 3/4" is not a lot of wood to work with; you want to use as much of it as possible without going all the way through.

You should drill some suitably sized pilot holes through the rubber and the wood. It's okay to go all the way through the wood, but you should place a piece of scrap wood on the bottom when making these holes. This not only prevents you from making a hole in your hardwood floor, but it also minimizes splintering on the bottom of the plywood.

Ahhhh, this makes me wonder...

I do have a rug I was intending to get rid of (5 by 8)... I wonder if I could use this somehow. Would still be short a foot but it'd be near the edge of the platform anyway. Hmmm.

I think a rug would be fine, but it'd have to be big enough to fit.

[KBKB]

I feel like I'd also still need the plywood even if only to have a "hard" surface upon which the load can be distributed (as opposed to having the soft mats distributing the load down into the hardwood).

This makes sense to me, especially if you're going to set your deadlifts down hard.

[TheToolbox]

I like the idea of .75 plywood + .75 mat + fender washer + normal washer + 1.5" screw.

I don't yet own a power drill so I'll likely need one to actually get through the rubber. Does it matter how "thick" the screw is (i.e. the diameter), or will anything do in this situation?

[OneForCrom]

If you're sticking with a bottom layer of plywood and you're worried about protecting your floors, you can get a thin (1/2" maybe) sheet of foam board insulation. It comes in different sizes, but you could do dropcloth, foam board and then your plywood.

[KBKB]

I don't yet own a power drill so I'll likely need one to actually get through the rubber. Does it matter how "thick" the screw is (i.e. the diameter), or will anything do in this situation?

It's not that critical, though I wouldn't use an extremely skinny screw. Maybe go for something like a #10x1-1/2" Phillips Round Head Wood Screw. If you can't find this screw exactly, don't sweat it. Pan head sheet metal screws will work too. (Don't forget the washers.)

A power drill and a set of bits is a tool that everyone (IMO) should own. I happen to like tools with cords. (I have a cordless drill, but do not remember to keep the batteries charged.)

Edit: Stall mats are dense enough that it might be possible to use a conventional wood screw with them. The advantage to doing it this way is that there would be nothing protruding above the surface of the mat. If you use this approach, you should get a screw that is less than 1.5" in length so that you can countersink it a bit.

If I were doing it, I would probably not use screws. Instead, I'd use a small amount of glue to secure the mat to the wood at each corner of the mat. As noted earlier, you'll probably be able to peel the mat up if you ever need to disassemble it.

[Cleveland33]

I like the idea of .75 plywood + .75 mat + fender washer + normal washer + 1.5" screw.

I don't yet own a power drill so I'll likely need one to actually get through the rubber. Does it matter how "thick" the screw is (i.e. the diameter), or will anything do in this situation?

why are you using a fender and normal washer? I wouldn't recommend that.

If you don't have a drill, get a self-drilling sheet metal screw, preferably with a hex head (and then a corresponding nut driver), you should not have any problems going through a stall mat and plywood.

[KBKB]

why are you using a fender and normal washer? I wouldn't recommend that.

Because I recommended it. I was worried about the screw pulling through the mat. But the mat is probably dense enough that this will not be a problem.

If you don't have a drill, get a self-drilling sheet metal screw, preferably with a hex head (and then a corresponding nut driver), you should not have any problems going through a stall mat and plywood.

That sounds okay too. Though it's probably better to not use screws at all. (See my earlier post about using a patch of glue at each corner of the mat.)

[Cleveland33]

Because I recommended it. I was worried about the screw pulling through the mat. But the mat is probably dense enough that this will not be a problem.



That sounds okay too. Though it's probably better to not use screws at all. (See my earlier post about using a patch of glue at each corner of the mat.)

I understand the use of a washer to keep it from pulling through, but why double them up? When you double them up, you get flat steel on flat steel and that will start to allow slop and the screw to start to work it's way out.

[KBKB]

I understand the use of a washer to keep it from pulling through, but why double them up? When you double them up, you get flat steel on flat steel and that will start to allow slop and the screw to start to work it's way out.

Fender washers are usually thinner than normal washers. When I've used fender washers by themselves in the past, I've seen the washer deform as the fastener is tightened. Thus, the normal washer is used to spread out the load over a larger area of the fender washer. For this application, I think that so long as the stall mat is compressed, it's unlikely that there will be any slop. (The fender washer is probably overkill though.)

But, after thinking about it some more, I'm not all that fond of the idea of using screws at all. Doing so places something rigid through a surface that is intended to compress. It'd be bad if a weight were dropped on one of the screws.

[Cleveland33]

Fender washers are usually thinner than normal washers. When I've used fender washers by themselves in the past, I've seen the washer deform as the fastener is tightened. Thus, the normal washer is used to spread out the load over a larger area of the fender washer. For this application, I think that so long as the stall mat is compressed, it's unlikely that there will be any slop. (The fender washer is probably overkill though.)

But, after thinking about it some more, I'm not all that fond of the idea of using screws at all. Doing so places something rigid through a surface that is intended to compress. It'd be bad if a weight were dropped on one of the screws.

Hmmm, never noticed fenders being thinner, I'll have to check.

I don't know, if you put screws in the four corners I don't think you'd have much to worry about.

[KBKB]

I don't know, if you put screws in the four corners I don't think you'd have much to worry about.

Probably not. But there's definitely nothing to worry about if screws are not used at all.

I've (definitely) changed my mind about the type of screw to use (if screws are used at all). Due to the fact that stall mats are (most likely) dense enough to not have to worry about the screw pulling through, I now think that flat head wood screws should be used. These can be sunk slightly below the surface of the mat which means that you won't catch your foot on one.

[KBKB]

OP,

When buying hardware, check your local Ace Hardware. The store near me has an absolutely fabulous Bolt Room which has a far greater selection of hardware than either of my local Lowes or Home Depot stores. (I go to Home Depot when buying lumber though.)

[TheToolbox]

After reading this discussion a bit I think I'd be more comfortable using glue. I think I need more experience with tools and screws etc first before committing to such a large project, especially when a simpler alternative exists. I think the glue would also be enough to hold the mats in place on the wood (especially if I do it in multiple spots).

Do you think something like Liquid Nails would work here?

[KBKB]

Do you think something like Liquid Nails would work here?

I have no experience with Liquid Nails, but my impression is that it's too strong for this job. It's possible too that it won't work well on rubber.

I think that a contact cement is good for this job. See: http://home.howstuffworks.com/uses-f...act-cement.htm

Try this product or something similar:



You apply the cement to both surfaces, wait about 15 to 20 minutes for both patches to dry, and then you stick the two pieces together. If you try to stick surfaces together when the glue is still wet, it will not work correctly.

When you need to take it apart, I think it's likely that you'll be able to pry the surfaces apart using a putty knife. If the putty knife alone doesn't work, pry up what you can with the putty knife and direct hot air in between the plywood and mat using a heat gun.

Glue just a few squares inches at each corner. If you go nuts and do the entire mat, you probably won't be able to take it apart very easily.

[TheToolbox]

Vapors may unleash flash fire. :O

Seriously though this is very helpful, thank you. I think that may be what I end up doing. I'll probably do the 4 corners (and possibly two in the middle, one on each mat, to the board below).


EDIT: Based on my quick research, contact cement is not flammable once the solvent dries / evaporates, so as long as the platform is being built away from electricity or fire (which this is), it should be plenty safe as long as I don't breathe the stuff.

[KBKB]

Seriously though this is very helpful, thank you. I think that may be what I end up doing. I'll probably do the 4 corners (and possibly two in the middle, one on each mat, to the board below).

Earlier, I mentioned the use of mending plates to hold the plywood pieces together. They won't be very strong, but they will be strong enough to keep the pieces from separating. (The plates are very strong, the weak point is the wood / screw interface.)

This is what a mending plate looks like:



If you use that type of mending plate, you'll need four screws per mending plate. Choose a suitably a sized wood screw.

[maltralson]

Hey Tool Box, my only caution with gluing your platform is if you ever have to move it, it will be very difficult.

I built a platform out of 3 sheets of 5/8" plywood and 2 4x6 stall mats, and there is no way it is leaving my basement in one piece.

For mine I got home depot to rip one of the sheets down the middle so I had 2 - 4 x 8 sheets and 2 - 2 x 8 sheets, so I put the one 4x8 sheet down and one 2x8 sheet down beside it, then I put the 2nd 4x8 sheet down overlapping the gap between the 2x8 & 4x8 then placed the last 2x8 sheet down to fill the gap. I then put 1" flooring screws all over the place through the two sheets of plywood. I put the stall mats down alternating so I have a 6'x8' platform and screwed a bunch more 1" flooring screws through the stall mats and into the plywood.

I cant lift this thing now on my own.

[TheToolbox]

Hey Tool Box, my only caution with gluing your platform is if you ever have to move it, it will be very difficult.

I built a platform out of 3 sheets of 5/8" plywood and 2 4x6 stall mats, and there is no way it is leaving my basement in one piece.

For mine I got home depot to rip one of the sheets down the middle so I had 2 - 4 x 8 sheets and 2 - 2 x 8 sheets, so I put the one 4x8 sheet down and one 2x8 sheet down beside it, then I put the 2nd 4x8 sheet down overlapping the gap between the 2x8 & 4x8 then placed the last 2x8 sheet down to fill the gap. I then put 1" flooring screws all over the place through the two sheets of plywood. I put the stall mats down alternating so I have a 6'x8' platform and screwed a bunch more 1" flooring screws through the stall mats and into the plywood.

I cant lift this thing now on my own.

Would you not be able to take the screws out of everything and move it piecewise?

[maltralson]

Would you not be able to take the screws out of everything and move it piecewise?

Totally, and thats why I didn't glue it.

[Seatard]

A pressure sensitive, releasable vinyl floor adhesive would work well to keep stall mats from sliding around on plywood. It is cheap, safe/easy to use, and available at all the home stores in the flooring section.

For joining plywood sheets together edge-to-edge the ideal fastener is a "tite joint fastener", sometimes in conjunction with a few dowel pins, often used to connect counter-top sections. These require an intermediate skill level and some basic tools for installation but are inexpensive.

I would suggest a non-slip rug underlay for the first layer of wood floor protection. They are some what breathable and formulated to not stain common floor finishes.

[TheToolbox]

A pressure sensitive, releasable vinyl floor adhesive would work well to keep stall mats from sliding around on plywood. It is cheap, safe/easy to use, and available at all the home stores in the flooring section.

For joining plywood sheets together edge-to-edge the ideal fastener is a "tite joint fastener", sometimes in conjunction with a few dowel pins, often used to connect counter-top sections. These require an intermediate skill level and some basic tools for installation but are inexpensive.

I would suggest a non-slip rug underlay for the first layer of wood floor protection. They are some what breathable and formulated to not stain common floor finishes.

Would such vinyl floor adhesives be able to hold them to the plywood even with all the weightlifting going on on top of the mats?

[KBKB]

A pressure sensitive, releasable vinyl floor adhesive would work well to keep stall mats from sliding around on plywood. It is cheap, safe/easy to use, and available at all the home stores in the flooring section.

For joining plywood sheets together edge-to-edge the ideal fastener is a "tite joint fastener", sometimes in conjunction with a few dowel pins, often used to connect counter-top sections. These require an intermediate skill level and some basic tools for installation but are inexpensive.

I would suggest a non-slip rug underlay for the first layer of wood floor protection. They are some what breathable and formulated to not stain common floor finishes.

Good information here. (I didn't know about tite joint fasteners.)

Repped.

[Cleveland33]

Good information here. (I didn't know about tite joint fasteners.)

Repped.

you think that's cool, searching for that lead me to this, which I think you'll enjoy Mr. T-Nut

http://www.rockler.com/riveting-t-nu...inserting-tool

[KBKB]

you think that's cool, searching for that lead me to this, which I think you'll enjoy Mr. T-Nut

http://www.rockler.com/riveting-t-nu...inserting-tool

Okay, so I know about T-Nuts (and have used them before), but I didn't know about riveting T-Nuts. (Reps on recharge / spread...)

FWIW, I disagree with this instruction from their overview: "Simply set the T-nut first with a hammer..." If you try that in oak plywood, the prongs will often bend or deform. I found that it's better to pull the T-Nut into place using a bolt from the other side. A piece of scrap wood with washers is needed distribute the load so as not to mar the work. Their advice is probably okay for softer woods.

The OP could use T-Nuts to bolt his rack to his platform.

[Cleveland33]

Okay, so I know about T-Nuts (and have used them before), but I didn't know about riveting T-Nuts. (Reps on recharge / spread...)

FWIW, I disagree with this instruction from their overview: "Simply set the T-nut first with a hammer..." If you try that in oak plywood, the prongs will often bend or deform. I found that it's better to pull the T-Nut into place using a bolt from the other side. A piece of scrap wood with washers is needed distribute the load so as not to mar the work. Their advice is probably okay for softer woods.

The OP could use T-Nuts to bolt his rack to his platform.

However you set them, I have to admit that riveted flange these create is awesome - both aesthetically and if you move things around a lot (like say changing grip placements on a rock wall) I have to imagine it maintains the integrity of the placement better.