Best "option" for basement floor

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Old 06-20-16, 07:00 AM
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Best "option" for basement floor

I am considering a few options for our basement floor. Under the concrete floor the contractor put down poly to block ground moisture from coming up. We do not have any moisture when taping plastic to the inside floor.

In the past I always raised the plywood subfloor on 2x4 sleepers however I am unable to do that because of the walkout basement door, the final step on the stairs, and for headroom.

Would my best bet be:

a. put down plastic, following by 1x4 pressure treated decking then the plywood? Or would it be better to put 1x4 decking followed by plastic on top of the sleepers, followed by the plywood?

b. put down DMX 1 step or delta fl followed by the plywood?

c. plastic followed by 1/2 in. of XPS then the plywood?

On top of the plywood will be padding and carpet.

Should I use any concrete sealer on the floor prior to this?

Is there a code where the final stair (last step to the basement floor) has to be the same rise as the rest of the stairway? I figure there does.

Thanks for the help
 
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Old 06-20-16, 07:17 AM
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It looks as if you have taken the proper precautions and have done the proper tests for moisture. IMO, none of the above. You won't be gaining anything by installing a sleeper system, nor applying XPS under your carpet. Since you plan on carpet rather than hardwood or laminate, I would have the padding and carpet installed directly on the concrete. You would save your walkout height, and probably eliminate the riser height problem. And, yes, risers need to be within 3/8" of each other. I feel adding your subflooring system will cause problems there, right?
 
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Old 06-20-16, 08:48 AM
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If I were to do the delta/plywood and carpet it would not impact the last riser as the builder had already adjusted for this and it would not impact the walk out door either. If i were to add sleepers then yes it would be too high for the last riser.

I am just worried about the carpet sitting on the cold concrete and any moisture that is in the air might condense on the concrete would slowly wick into the pad, but then again we run a dehumidifier down there.

Maybe I will just do with the delta fl for piece of mind.
 
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Old 06-20-16, 10:25 AM
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Delta fl without additional plywood, right?
 
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Old 06-26-16, 08:18 PM
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Fastening basement sub floor with Hilti powder shot.

It is now recommended to use tapcon when securing plywood to concrete (over delta FL in this case). I already have a good hilti and would would like to use this instead of drilling and screwing as its a large 900 square feet area. Are there any downfalls to securing the subfloor with the hilti and washer fasteners? It is a 6 month old pour of concrete so it should not be that hard. I might have to hit a few a second time with lighter load.
 
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Old 06-26-16, 08:53 PM
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I'm not the pro here but I have a question for you. Do you plan to attach a plywood subfloor directly to concrete with no sleepers (2x4's) under it to allow it to breathe ?

Even with plastic sheeting down I'd be worried about moisture under the floor especially in a northern state.
 
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Old 06-26-16, 09:10 PM
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Going to need far more back ground info.
What's the finish floor going to be?
Is this below grade?
No way would I be using a power driven fastener for a subfloor!.
 
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Old 06-26-16, 09:15 PM
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I've added a link below which discusses many of the issues related to concrete floors, not all related to what you are doing, but the science is good. Near the end of the article it discusses the issues PJ mentioned with an air gap below the plywood.

The majority of basements are not well suited for a living space conversion. If the builder followed all of the proper design steps and your soil and drainage favor you, then you may have good results. Unfortunately, you will not have the test of time to tell you what might have been missed.

As for the Hilti vs Tapcons, it would be nice to thing that the floor will never get wet, from outside, below, or a broken pipe, but that would be optimistic and removing those hilti fasteners, if necessary to dry things out, well, more difficult than the Tapcons.
Bud
Concrete Floor Problems | Building Science Corporation
 
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Old 06-26-16, 10:13 PM
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The subfloor has been laid over Delta FL (a plastic dimpled membrane) so I is raised slightly and not in direct contact with the concrete. The delta FL directions say to use tapcons 8 per sheet. Why not a hilti?

It's new construction... Foundation is waterproofed on the exterior.. And the basement floor has poly underneath the slab. Moisture test shows not moisture coming up. The basement is bow grade walk out colonial house.
Has anyone tried to remove a tapcon in 5 years after the concrete has hardened further? Either way I imagine your going to be ripping up the floor in a flood and cutting the powder fastner or broken tapcon out. (same as if any other part of your house was damaged from a flood).

In the past I have done 2x4 sleepers laid flat as you suggest... Which were powdered to the concrete... Then plywood screwed to th e sleepers. Why can't the ply be powdered through the delta to the concrete?
 
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Old 06-27-16, 04:10 AM
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I have merged the two threads you have going on this subject. One reason not to use hard fasteners through the Delta FL is that it is a moisture barrier. You put holes in it and it becomes a sieve.
 
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Old 06-27-16, 05:02 AM
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The instructions that come with the delta say to screw it down with tapcons.... isnt this hard fasteners? Believe me I would love to not have to tack it down and leave it without any holes but am afraid the carpet will pull the sides up and the t/g will slowly walk and bow. The delta instructions say 8 per sheet (4 corners, outside edge of the middle and the center 1/3). This seems overkill, especially with T&G. How few do you believe I could get away with and where on the sheet?

I put the delta and ply down to give the floor a warmer feel over the concrete. Carpet will be on top of this. As I mentioned earlier there is poly under the slab which sits on about a foot or so of crushed stone so there should not be much moisture coming up. In addition all downspout are piped underground downhill and exit approx. 20 feet from the house. I did not want to do carpet directly on the slab because the sub gives it a warmer feel. The hot water heater has a pan under it that is tied into a footing drain... and I also plan on adding a sump pump extra backup.
 
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Old 06-27-16, 06:25 AM
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Since I used tongue and groove, can i just tapcon/ramset around the perimeter of the entire basement to hold it all together and keep the edges from curling due to the carpet? Or will this all start to warp. If i only did the edges I would also only screw down where there is notable bounce. This way there is minimal holes in the DeltaFL.

Would gluing the TG seams help if i only did the perimeter?
 

Last edited by hammerdown22; 06-27-16 at 08:28 AM.
 

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