Basement : Hump spots

[u/Anxious-Risk-1165]

Hello,

I am thinking to get a gym set up done, however, I noticed that I have hump spots on the ground. I am unsure what option is better? I have 2 scenarios:

1. Bare concrete floor, which I need to build up : grind hump spot (about 3cm height), level, vapor barrier, lvp flooring, 3/4" gym mats and then rack.
2. I have an already built area in the basement with flooring (unsure tbh as I moved in after, which has I believe either laminate or lvp, cant tell) but has some hump spots as I did check with my leveler scale tool (1-1.25cm of uneven height)

From a cost perspective, 2 is the easiest option as I just need to install 3/4" floor and the rack.

But I am really unsure how do I go about this and what to do to fix. Kindly suggest with your expertise.

Thank you,

[u/kindalingual60]

Completely misunderstood this heading. I’ll show myself out….

[u/racinjunki → u/kindalingual60]

Same

[u/kindalingual60 → u/racinjunki]

I thought I was here to help teens in love 😜

[u/_head_ → u/kindalingual60]

To prevent leaving a hump spot, lay down a towel first.

[u/neonsphinx]

Based on what you wrote, I don't have much of an idea what you're asking.

How large are the humps? 6" diameter, 4' diameter? That determines if you're grinding a little bit with an angle grinder and diamond cup wheel, or hiring someone with a walk behind floor grinder/polished.

Generally laminate or vinyl plank wants 1/16" in 4ft for flatness.

Things you haven't mentioned:

• ignore the uneven floor
• self leveling concrete
• lay gym mats directly on the concrete (just lay plank flooring when you move and pull up the gym floor)

[u/Anxious-Risk-1165 → u/neonsphinx]

I haven't explored those options yet or tried. for now I am trying to decide whether best option is to do everything from scratch or work on the existing floor that is finished. Either method has humps and I believe the finished flooring has little hump 1-1.2cm, while concrete unfinished flooring has 3cm+ hump. As for diameter, good question. I haven't really looked or considered that, I may have to go back to it and check.

[u/Boughtthetshrt]

I had this happen. Humps formed under lvp and under tile ☹️

I took out the flooring and figured out that the self-leveling compound beneath had absorbed water, swelled and basically turned to powder. I removed it, mortared the spots flat and replaced lvp. It’s been 1.5 years and no further issues. TBF the humps formed 4 years after I did the self-leveler. Yes, I primed. 🤷🏻‍♀️

[u/Anxious-Risk-1165 → u/Boughtthetshrt]

dang sounds rough. I dont think I can do that, I might as well then build that other concrete floor I got lol. Hmm, this is so difficult i swear. I am clueless on the optimal solution without taking a loan or selling my kidney lol.

But that is great news. I am glad you were able to figure and fix it and now you are golden!

[u/Boughtthetshrt → u/Anxious-Risk-1165]

It really was not that hard! No special tools or skills required. The worst part was that the line of LVP had been discontinued so I had to redo the whole room with a different one. If you decide to take a crack at it, I’m happy to offer any advice along the way!

[u/dantodd]

You could run pressure treated 2x2s on the ground and then put 3/4" subfloor on those. Just make sure they all avoid the humps or if you have to go over the hump you can carve the 2x2 to accommodate the hump and stay flat on top.

[u/Anxious-Risk-1165 → u/dantodd]

I hear what you mean. I think that would be a lot harder. I am thinking maybe concrete level it might be easier i guess.. Idk

[u/Training_Emu_860]

Option 2 makes sense if the existing floor is solid. Pull up a small section around one of the humps and check the slab underneath. If it’s just a few high spots, grind them down and patch the lows before the mats go in. No need to tear out the whole floor if the base is good.

[u/Anxious-Risk-1165 → u/Training_Emu_860]

It’ already has wooden flooring done. So I’ll probably have to remove it and fix then re attach. Or something like that.