basement subfloor question

[bhostasa]

Hi guys. I am finishing our basement and have a questions re: the flooring.

The basement has had some water issues in the past (which I'm addressing w/ a sump and drain when the weather breaks). I am planning on installing engineered wood flooring in some areas and carpet tiles in others.

I've been thinking about installing a subfloor beneath the wood and carpet to help with warmth and the comfort factor. I'm looking at installing 1/2" styrofoam that is moisture resistant and 1/2" OSB (with a vapor barrier underneath). I have to watch my total height as I have 1-1/2" to the bottom of my exterior doors.

Does this seem like it would work? I am planning on using construction adhesive and tapcons to adhere the OSB to the concrete.

Any thoughts on this? Thanks!

 

[studor]

www.dricore.com/en/aboutus.aspx
Given the thickness you have to work with and the wet conditions I would use (and have) this stuff. It works, makes the floor warmer and is probably about the same price or less as your planned approach

 

[bhostasa]

I looked at that stuff. I think it's out of my price range. It was about $1.75/sf. The way that I was describing is about $.53/sf.

I have approx. 1300 sf to do so that's a pretty big difference.

 

[framer]

Snap in flooring floats. They have 3/8 product to lay under for bsmt.
less than inch thickness.We have a floating floor love it. Good luck

 

[GPintheMitten]

My advice is do your water management tasks and then do nothing for one year. In doing so, you'll have given yourself the opportunity to see various conditions throughout one year cycle and determine if the water proofing has worked successfully and address any issues.

I would do this, before I put all the time, effort and money in floor coverings and other improvements.

If you have to come back and rip out a bunch of stuff because it got wet/damp and moldy, it will cost you a lot more.

 

[robb01]

Id go with the floating interlocking grid system, it worked well for us

 

[Egon]

My advice is do your water management tasks and then do nothing for one year. In doing so, you'll have given yourself the opportunity to see various conditions throughout one year cycle and determine if the water proofing has worked successfully and address any issues.

I would do this, before I put all the time, effort and money in floor coverings and other improvements.

If you have to come back and rip out a bunch of stuff because it got wet/damp and moldy, it will cost you a lot more.

That is very sound advice.

And maybe reconsider that OSB to some exterior grade plywood.

 

[JB4310]

I've never used it but would recommend those panels with the plastic bridging underneath, it's similar to the geotextile materials we use in the basement waterproofing work we do. You need a break between your concrete floor and sub-floor and that's the easiest way to get it, worth saving for.

I usually recommend against sub-floors in basements but if you have to then those panels seem the way to go. Would not glue OSB to floor, though you mentioned vapor barrier and foam insulation so not sure what your planning?

In general for water control we recommend less layers and more free space/buffer between concrete and finished building materials.

JB.

 

[Luremaker]

Instead of using the expensive drycore panels why not use the Platon dimpled membrane right on your floor. Tape and seal then place your T&G plywood right on top of the platon.

System Platon - Flooring

 

[Egon]

There is also a "Schluter system".

http://www.schluter.com/2080.aspx

 

[JB4310]

Instead of using the expensive drycore panels why not use the Platon dimpled membrane right on your floor. Tape and seal then place your T&G plywood right on top of the platon.

System Platon - Flooring

Yup I was thinking the same thing, that's how I buy it in 4 ft wide rolls, probably easier than those 2x2 panels and cheaper.

Lowes had a similar product but I think it had a filter fabric glued on the dimple side (Cuspated core)

JB

 

[bp fick]

My advice is do your water management tasks and then do nothing for one year. In doing so, you'll have given yourself the opportunity to see various conditions throughout one year cycle and determine if the water proofing has worked successfully and address any issues.

I would do this, before I put all the time, effort and money in floor coverings and other improvements.

If you have to come back and rip out a bunch of stuff because it got wet/damp and moldy, it will cost you a lot more.

Maybe it's we Mitten guys, but I agree!!!! Whole heartedly. Do absolutely nothing until you are sure, sure, sure you have your water table issues resolved. Your budget would really be stung if you put down anything, only to have it soaked. Also, do not build in a natural home for dangerous mold.

 

[studor]

I agree with checking the water problems but when you add up the cost of the Schluter and other membranes the Dricore may not look so expensive. I would say that even with a basement dry for a year I would still use one of these systems rather than invent my own -- the cost of doing it right the first time is always less than doing it right the second time

 

[bhostasa]

Instead of using the expensive drycore panels why not use the Platon dimpled membrane right on your floor. Tape and seal then place your T&G plywood right on top of the platon.

System Platon - Flooring

I've never seen that stuff before. Looks like a good alternative.

Since you used the T&G, did you have to fasten every piece?

How thick is that stuff? Any idea of cost/sf?

I'm going to try to go to Menards today and see if they carry it around here.

 

[bhostasa]

I agree with checking the water problems but when you add up the cost of the Schluter and other membranes the Dricore may not look so expensive. I would say that even with a basement dry for a year I would still use one of these systems rather than invent my own -- the cost of doing it right the first time is always less than doing it right the second time

Good point.

 

[bdeboer]

I've never seen that stuff before. Looks like a good alternative.

Since you used the T&G, did you have to fasten every piece?

How thick is that stuff? Any idea of cost/sf?

I'm going to try to go to Menards today and see if they carry it around here.

Lowes has a similar product which I used last fall. I can't remember the name right now. Comes in a roll with tape for the seams. It prices out cheaper than dri-core.

We carpeted the room over 3/4" tongue and groove osb and let it float. There is a noticeable difference when stepping from the concrete floor onto the carpet.

 

[bdeboer]

Delta-FL is the product I used:

DELTA®-FL - Vapor Barrier for installation on concrete slabs, provides a warm and dry floor

The spec's are on this website. Installation instructions are located under the download tab.

I chose to not drill my floor. They do recommend plywood "H" clips for the 4' ends of the plywood, hard to locate for 3/4" locally. They do recommend securing the subfloor to the concrete for laminate or hardwood.

 

[Luremaker]

I've never seen that stuff before. Looks like a good alternative.

Since you used the T&G, did you have to fasten every piece?

How thick is that stuff? Any idea of cost/sf?

I'm going to try to go to Menards today and see if they carry it around here.

I have never actually used this product. It's sold at the local Home Depot store and seems to be the same dimpled plastic base as used on the drycore product. See the manufactures web site for detailed installation instructions. The local Home Depot sells it for $129 for a roll 6-1/2 ft x 65-1/2" long ($0.302 /sq ft CAD). I am sure it is cheaper in the USA. It is 24mm thick.

System Platon - Flooring

The photo came from an installers website.

 

[bhostasa]

I really like the raised, plastic subfloor idea. Seems like exactly what I need.

There are two available in my area: Platon and Delta FL. There is a $.3/sf difference between the two. Beyond that, the only other difference that I can find is the Delta recommends 5/8" OSB and Platon recommends 7/16".

Does anyone have any additional thoughts or preference between these two?

 

[JB4310]

You want tongue and grove or equivalent hurricane clips to keep the edges aligned if you don't want to have to screw the heck out of it.

I would think 1/2 would be fine, not sure which sheathing would be better, OSB or reg plywood? I would definitely put SOME screws in each sheet.

The advice about waiting a full 4 seasons is good, and exactly what I tell my own customers after doing a basement water control job for them. I know it's not very practical but as mentioned if we have to go back under the floor to add or repair footing drain system, there will be no collateral costs dealing with finished walls/floors.

In your case if you only had minor seepage that didn't require extensive work, or if you are unwilling to do extensive work, then I would say do what you planned now, definitely use the dimpled drain material under sub-floor, you would IMO need that regardless of known water issues for a wood floor, if it were just carpet you might get away without it, most people do. but for any type of wood you need that break.

JB.