I have started working on finishing my basement. I have install Dow's Wallmate against the sealed walls. Talking to a friend, he said I should have first sealed the area between the floor and wall to reduce radon levels and then install a pressure treated 2x4 on the floor before installing the Wallmate on it. He said the 1x3 boards used to attach the Wallmate are not pressure treated and since it runs all the way to the floor (to insure it will hold the future drywall board) it would be in direct contact with the cement floor. Placing the pressure treated 2x4s as a sill plate, the non-treated wood would ride on top.

The Wallmate is 1 ½ “ thick, a 2x4 is 3 ½ “ thick, do I use a 2x2s instead?

Once the Wallmate was installed, I planned to build a second 2x4 wall to house the electrical and provide for future expansion once the drywall was installed. Should a vapor barrier be used, where?

What is the correct process for installing Wallmate in a basement? The house was built in 1990 and I have cinder block walls treated with Drylock and a poured basement floor. I will remove all previous work, as I don’t envision energy costs going down anytime soon.

Thank you in advance for any insight into my dilemma.

Bob, lets start with a basic question or two. Has your home every had any seepage at all? Have you tested the floor for moisture coming up through the concrete. Test by taping all four sides of a plastic sheet or bag to the floor with duct tape. Check it tomoorw to see if thyere are any droplets of water in the bag. Radon sealing, not a bad idea but don't count on your seal preventing an issue with radon. Do radon test before you go any further, a radon medigation system may alter your room. Could you clarify this statement "build a second 2x4 wall " is there another 2x4 wall already in place? Your friend is correct about the floor plate, pressure treated for sure. Back to you for some more info.

Thank you for the reply.

I have placed and taped plastics to the basement floor and will see what tomorrow brings.

The "second 2x4 wall" should have read, "in addition to the Wallmate being placed against the foundation wall, I would want to install a second wall between the Wallmate and the interior space consisting of 2x4s for the drywall to hang on. This then gives me a hollow space for electrical and provide for future expansion once the drywall was installed."

I will email you the results of my moisture test tomorrow.

Thank again and good night.

That will be great. Most basement walls are constructed laying on the floor and then raised into position. Floor plate nailed with a nail gub and the top is shimmed once it is square and level. This wall never actually touches your wallmate.

ballengerb1,

I have pulled the plastic test strips from the cement floor. I had placed two about 40 feet apart. I remember when the concrete was poured. The crew had placed heavy plastic down on top of the slag before the rebar and concrete pour. I don't know if this had anything to do with my results but both test squares of plastic came up bone dry. That is a very good thing. I don’t want any mold or mildew growing in the basement.
One other thing about the basement: I have a sump pump and drain tile both inside and outside of the foundation with both empting into the sump basin
.
Now to the wall: I would like to run the following plan by you.

1) Remove all previously constructed wall down to the cinder block, which was sealed with Thro-seal.

2) Clean up the edge where the floor meets the wall.

3) Chalk the edge where the wall and floor meet. Radon prevention.

4) Place a 2x6 pressure treated sill plate, using nail gun and construction adhesive. I’m using the 2x6s as the Wallmate is only 1 and 1/2:” wide while a normal 2x4 is 3 1/2” thick. By using the 2x6, I don’t have to cut down a 2x4 for the Wallmate.

5) Install Wallmate to treated walls, resting on sill plate, using pressure treated or painted 1x3s to attach Wallmate.

6) Install plastic vapor barrier over the Wallmate.

7) Construct a 2x4 wall on the floor and place on the pressure treated 2x6 installed earlier. (The Wallmate will use 1 ½ “, the stud wall will use 3 ½”, for a total of 5”. That will leave a ½” lip for the drywall to rest on, keeping it off the floor.) The stud wall will remain as a hollow cavity to run wires and for future expansion.

8) Cover the framed wall with 5/8’ paperless wallboard. Tape, mud and sand as necessary.

9) Paint and enjoy basement.

Boy does that sound easy but I know it will be a lot of work.

Your thoughts on the above.

Thank you in advance for your time, effort, and insight,

Magicman Bob

Yes, your moisture tes gave great results. Did not recall that the walls were cinder bloc (concrete block) but you never answered my very first question completely. Has there ever been any seepage at all including the walls. 1. sounds good but reseal any anchor areas that are l;eft fromtaking down the walls. 2. wire brush and vac 3. Its OK but doesn't really stop radon. Check the aisle where they seal Thor-seal, they have a caulj in a gallon can that can be troweled on. 4. don't see that a 2x6 is better than a 2x4. The wallmate and the stud walls should not really touch. Wallmate goes on the actual wall and will follow the waves in the blocks. The stud wall stands off the back wall by about 1/2". I think your thought might become an issue if the block wall has any wave or bump to it and most of them do. 5. I have been meaning to ask you why you want wallmate when you plan to drywall, just for insulation? 6. the vapor barrier should be under the wallmate. You are stopping moisture from entering not leaving. 7. Yes construct on the floor and raise into position on the floor plate, shim at top and square, plumb. 8. paperless is good for this application. If you have done any taping you know how long that first coat takes to dry. Buy a couple of bags of 45 minute dry mix compund and mix it yourself. Dries rock hard in 45 minutes, use the 5 gallon can of redimix for the next two coats. Avoid sanding and try a well wrung sponge to feathger the edges. 9. Hit it with primer so you'll only need two coats of the good stuff. 10. Pop a brew for me too. Sounds like you have a great plan. Now you can get to the flooring materials.
Good luck, Bob