Flooring Underlayment

[Dr Dave]

Menards and Home Depot have roles of a dimpled plastic product that you lay down first, plywood on top, it is not secured. It works like the drylock panels, but cheaper.

Dave

[Milo]

Rather than go to all the expense of raising the floor I would just install a vapor barrier then lay down one of the premium (thicker) sound deadening, insulating, underlayments and choose one of the thicker, maybe 8mm+ laminates. Then make whatever kind of transition pieces necessary for where the laminate terminates or meets another surface.

[KennyG]

I've used dri-core and it's great, but the OP said he only wanted 1/2". Isn't all the dri-core thicker than that? I would test the floor for dampness by taping down plastic for a day or two and seeing if it's significantly wet. If not, I would just put down a layer of cushioning underlayment and let the laminate float on that.

[B7510HSD]

Thanks for all the ideas guys I'll check them all out and try to figure out what will work the best! I need 1/2" as the rest of the floor will also be laminate!

[Tractor Seabee]

Thanks for all the ideas guys I'll check them all out and try to figure out what will work the best! I need 1/2" as the rest of the floor will also be laminate!

I just did a whole basement (1200SF) with laminate. It was very uneven, lots of cracks, and in a moist subgrade area. Checked all levels and determined high spots. Highest point became the reerence level. Prep: Used a cup shaped carbide concrete grinder in a 6" anglehead grinder to remove all paint and previous tile cement, gouged out all the cracks with a diamond saw blade in power hand saw, filled with epoxy patch,and put a layer of drywall fiberglass tape over all cracks embedded in epoxy. Finish: Went to a contractor specialty supply (the big box stores do not have the big sacks) and bought a pallet full of high grade self leveling underlayment. Installed a piece of ripped lumber (thickness based on reference level) at each door (5)and Rolled down a coat of masonry latex bonding agent. Mixed underlayment per instructions (water is critical measurement) and poured in place one room at a time. A small bull fload works well to consolidate and spread around. After curing of underlayment rolled down a heavy coat of asphalt waterproofing emulsion, put down a 15# asphalt roof felt in the emulsion and put two coats on top. After that cured I layed the floating laminate floor on top. Turned out beutiful. total material including laminate was less than $1.5K. Costco was closing out laminate at 50% off which helped on the cost.

Depending on your conditions; some of the above steps can be bypassed. I had the worse of all conditions to mess with.
I would not hire out to do this for someone else for less than $3K labor cost.

Ron

[B7510HSD]

I just did a whole basement (1200SF) with laminate. It was very uneven, lots of cracks, and in a moist subgrade area. Checked all levels and determined high spots. Highest point became the reerence level. Prep: Used a cup shaped carbide concrete grinder in a 6" anglehead grinder to remove all paint and previous tile cement, gouged out all the cracks with a diamond saw blade in power hand saw, filled with epoxy patch,and put a layer of drywall fiberglass tape over all cracks embedded in epoxy. Finish: Went to a contractor specialty supply (the big box stores do not have the big sacks) and bought a pallet full of high grade self leveling underlayment. Installed a piece of ripped lumber (thickness based on reference level) at each door (5)and Rolled down a coat of masonry latex bonding agent. Mixed underlayment per instructions (water is critical measurement) and poured in place one room at a time. A small bull fload works well to consolidate and spread around. After curing of underlayment rolled down a heavy coat of asphalt waterproofing emulsion, put down a 15# asphalt roof felt in the emulsion and put two coats on top. After that cured I layed the floating laminate floor on top. Turned out beutiful. total material including laminate was less than $1.5K. Costco was closing out laminate at 50% off which helped on the cost.

Depending on your conditions; some of the above steps can be bypassed. I had the worse of all conditions to mess with.
I would not hire out to do this for someone else for less than $3K labor cost.

Ron

Wow sounds like alot of work!! This is new concrete it was an add on 22'x10' to the existing older house...and it is above grade so other than the moisture in the concrete it shouldn't have a water problem..

[Tractor Seabee]

Wow sounds like alot of work!! This is new concrete it was an add on 22'x10' to the existing older house...and it is above grade so other than the moisture in the concrete it shouldn't have a water problem..

It was a lot of work. For the underlayment go to Addison Supply in Tacoma. They are great and will help you with the details. I have been using them for 10 years.
Get the latex bonder at Loews as it is cheaper and comes in gallons.

Ron

[smilindave]

if your floor is fairly level, just use some 1/2" hardy backer? 100% water proof and it lays flat. Lowes and Home Depot usually carry it. Since you are using laminate flooring, no need to cement or fasten in place

[clemsonfor]

I would never use Laminate. I know 2 people with it. One is super cheap stuff. Its chipped at edges and is "blown up" where water sat on it unnoticed and then the "sticker" for the fake wood wore off. The other couple has what they call cheap laminate. To me its not really that cheap, was something like $3-4 sqft. It was real wood veneer adheared to like 3/8 ply. The finish is worn off in high traffic areas after like 3 years or so.

Now i dont deny that some of the stuff looks good and will last, but the good stuff costs more than real hardwood??

I laid solid 3/4" hardwood 3.5" wide planks in my home in a room that i redid the floor in. If memory serves me right i paid i think Around $3.50sq/ft give or take $0.20? Yes i had to finish it but thats really not that hard if you can stay off of it for a week or so.

[radioman]

I saw a show where holmes for homes took blue foam board and used that to insulate the concrete basement floor and installed 3/4 plywood on top. He used tapcon screws to hold all this down. This is obviously much thicker then OP needs, but it gives you the idea that tapcons should be ok. If you dont have water issues, and once the floor is in, you really dont need to worry about rust of screws - it probably will last 20 years or more and still hold.