Need advice for floor removal

[Nazer]

Hello everyone,

My house is a slab in NW Georgia. I ripped up a 1'X1' section under the fridge today and it looks like I have real hardwoods stapled to plywood that has been glued down to the slab (also has some nails with barbs into the concrete). The floor has some bad spots where it makes poping sounds when you walk on it, I am not sure if that is the staples being loose or the glue having air pockets, but Im pretty set on completely redoing the floor. Refinishing is not really an option since there is so many noisy spots when you walk. I plan to lay a floating LVP. I have a few questions I would love some feedback on.

1. Should I try to keep the plywood and lay the LVP on top of it or should I rip it up and take up all the glue and grind the nails down? The floor seems to be pretty flat, but Im nervous that they did some trickery with the plywood and glue to hide a uneven slab.
2. It seems they generally have 2 kinds of LVP, flexible vs rigid. If I go down to bare concrete which type would be better for going directly on the slab?

 

[Guyfromtexas]

I'd remove the hardwood flooring for sure and then grind the staples down. For any popping and soft spots in the plywood I'd shoot 1 1/4" concrete nails in them spots with a Ramset. If removing the hardwood is too much and you're aren't worried about the height difference then keep the hardwood down and shoot 2" concrete nails in your popping spots and then install the LVP. Removing everything would be the way to go though and then use leveler over the slab if needed. Both products will be fine for slab but use a moisture barrier on it. Good luck.

 

[Nazer]

I just removed the flooring, the plywood looks to be in pretty good condition. The noise was from the cheap underlayment they used and low spots where there was a void between the hardwoods and the plywood. The plywood itself doesn't make noise. I going to to mimic it in the bedrooms to bring everything up to the same level.

Someone told me that even though the plywood hasn't had moisture issues in 24 years, that it will if I lay LVP over it as it will cause water vapor to get trapped? Is that true?

 

[Guyfromtexas]

Your subfloor floor actually looks pretty good. If there was moisture under there you would of already seen it. The plywood would be buckling and discoloration in places and you don't see that. You usually don't need a moisture barrier over plywood, that usually gets done before placing that plywood. Just float out your plywood joints with some leveler or floor patch (mix latex additive instead of water) and you're good to go.

 

[Nazer]

That defiantly sounds doable and will save me from death by wife, she doesn't want to tare up the plywood lol. Do you have any recommendations on mimicking this in the bredrooms where it is just the slab? I would like all the floors to be on the same grade.

From my research it seems I have 2 options, seal the slab then use flooring glue to glue down the ply followed by some tapcons or just lay a 6mil plastic down and use only tapcons to secure the plywood.

Appreciate your input.

 

[Guyfromtexas]

Do you have any idea why they used the plywood over the concrete to begin with? Sorry if I missed if you explained that. Only one way to keep the same height for the bedrooms is to put plywood down like they did in the living room. You could possibly put a reducer in your doorways and keep the bedrooms as they are and just install the LVP over the plastic. Only other option is to put plastic down and fasten the plywood with 1 1/4" Ramset nails or Tapcon screws.

 

[Guyfromtexas]

That defiantly sounds doable and will save me from death by wife, she doesn't want to tare up the plywood lol. Do you have any recommendations on mimicking this in the bredrooms where it is just the slab? I would like all the floors to be on the same grade.

From my research it seems I have 2 options, seal the slab then use flooring glue to glue down the ply followed by some tapcons or just lay a 6mil plastic down and use only tapcons to secure the plywood.

Appreciate your input.

Here is a my Ramset Cobra concrete nailer. Heck of lot faster and easier than the manual. Ebay has some good used ones for sale. The nails and 27 cal. loads I have pictured.

 

[highup]

I'm not agreeing with them trying to hide an uneven slab. If they wanted wood floors, they probably had to install plywood...... Well, maybe not these days because there are moisture limiting adhesives and coatings. Back when that slab was done, maybe not.
The areas with popping sounds could probably be fastened down, possibly with screws that are designed for concrete. Look up Tapcon fasteners to see what I mean.
You would probably have to coat the screws or holes with a long lasting sealant when driving them in.
Staples that may have poked through or otherwise compromised whatever sealant is under the plywood is your call since we can't see what you can. Maybe not an issue.... maybe it is.

 

[highup]

I didn't see you were already up to speed on Tapcon screws.
There are a lot of pop areas or just a few?

 

[highup]

Bruce floors had a method where you troweled something similar to roofing patch onto the concrete, then rolled out 6 mill plastic into the adhesive.
I'm sure something similar is done when nailing down plywood. I've never done either.

 

[Nazer]

There is no noise now that the the flooring and roofing paper is gone. The Plywood doesn't make noise, it has some hollow spots but you don't notice them unless you tap on them with a hammer. I plan to drill a hole in a few of the bigger hollow spots and fill with construction adhesive then drive a tapcon.

The floor definitely isn't level, Im going to have to level some spots on the plywood and there are quite a few hollow spots. So either they really wanted nail down hardwood or they were trying to avoid leveling. Either way the plywood feels solid and this isn't our forever home. So I don't want to screw the next owner with a crap job but I also need to keep the cost low since we have 2100 square feet of flooring to buy. I think in the end the plywood will be a benefit to the feel of the floating floor. Should give it more "give" and stay warmer.

 

[highup]

The clicking sound that you heard may have just been the tar paper sticking to the plywood and then unsticking from the plywood each time you stepped on it. Especially noticeable if the floor is cold or cool. The tar paper isn't necessarily sticky, but it's tacky enough two stick then release especially in hollow spots where the floor gives or flexes.
There has to be some sort of a membrane or more tar paper and adhesive underneath your plywood. If you drill into that and pump in something that's not compatible with the moisture blocking material underneath you might run into trouble. Find an unimportant area maybe the back corner of a closet and saw out a 6 by 6 inch square of plywood and find out what's underneath it.

 

[highup]

I wish our old buddy from Arizona would pop in to assist you he's familiar with plywood on concrete. I simply know that it's done, but I've never done anything like that personally.

 

[Nazer]

I cut a 1'x1' piece completely out under the fridge and it looks like the only glued it to the slab. Shotty work imo, but its what I got to work with. I wish I had the money to do it right and go down to concrete and get it leveled, but that isn't in the budget. I'm tempted to cut up a piece in the middle of the floor to make sure they didn't just glue the edges. With the hardwood flooring they stopped the tar paper about 3 inches from the wall and glued the edges down.

 

[highup]

I didn't know that top photo was the concrete. I would expect the roofing paper be glued to the concrete and the plywood installed on top of that. I mean, why trap moisture in the plywood?
Maybe there is a vapor barrier under the slab and moisture isn't such a concern. You'd have to ask local be builders or lumber yards if that's something common in your area. (Speaking about vapor barrier under the slab)