Subfloor suggestions for this room

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vinny186

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this space is going to be an exercise room so there is going to be a lot of extra weight on it. I'm going to frame the inside of the hole and lay down plywood or OSB.
There are a couple issues. First, the border around the hole is slightly raised, about 1/4" or slightly less which shouldn't be a problem.
My primary question is should I lay down 1x2's or possibly 1x3's because of the weight or skip that all together and go with a dimpled subfloor then plywood/OSB on top?
 

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ChrisAtTech

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Check the weight limit on the dimpled subfloor product you plan to use but that should be a good solution. I looked a couple up and they had high compressive strengths. You'll need to also put a vapor barrier down against the concrete under the framing you use to fill in the hole. I think elsewhere most of those dimpled products work as their own vapor barrier but if you went without it you'd need a separate one.

That border around the hole may be a problem, most flooring require very little height change, something around 1/8" or less over a 6' length (varies by product). Could you add your framing to match the height of the raised area then use a different thickness plywood on top? For example 1/2" plywood in most of the room and 3/8" over the opening? Then, your surface for the flooring would be more even.
 

vinny186

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I thought whether I used 1x2's laid flat or the dimpled flooring, I could notch out the wood or cut the dimples where they pass over the elevated border.
That's a good idea to check the weight limit.

As time is money, I wonder which would be cheaper, to tapcon all the 1x2s then screw plywood into those or roll out the dimpled subfloor and screw the plywood to the concrete with tapcons.
 

AndyGump

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I don't really understand what it is that you are trying to do here but if you end up framing anything in that concrete hole you should use pressure-treated wood if it is going to be in contact with the concrete.

Andy.
 

havasu

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....And paint a mmoisture barrier on the slab to stop underslab water intrusion.
 

vinny186

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There's a product called Ghost Shield meant for coating cement floors but if there moisture and it can't penetrate the cement, where does the moisture go?
 

BuzzLOL

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There's a product called Ghost Shield meant for coating cement floors but if there moisture and it can't penetrate the cement, where does the moisture go?
The moisture stays in the concrete... where it always is...
 

havasu

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The moisture stays in the concrete... where it always is...
And under the concrete, through breaks in the moisture barrier, if you are lucky to have one.
 

vinny186

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More detail:
I'm helping a friend with a basement exercise room. At one point there was a 9x4 resistance pool but it's been removed. The concrete curb you see in the pic is about 1/4" higher than the rest of the floor so it has to be accounted for with any subfloor we choose. I plan to first frame out the hole level with the rest of the floor or 1/4" below the concrete curb. There will be 2 treadmills, an exercise machine with a weight stack and a rack of dumbbells on top of this floor.

We see three subfloor options:
1. Dimpled subfloor (5/16") with 3/4 tng osb on top and rigid vinyl flooring planks
2. 1/2" Foam board with 3/4 tng osb on top
3. Floor leveler with vinyl floor planks installed directly on top

I'm concerned about the weight with the foam board and dimpled floor. I figure I can notch out the foam board where it passes over the curb or flatten the dimples.
 
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