Hello,
I am a recent first time homeowner who has been looking forward to finally be able to make changes/improvements to the house I'm living in. I don't have a ton of experience but I pay close attention to detail and thoroughly plan out these kind of projects

With that disclaimer out of the way, I'm hoping to get some advice regarding my options for installing a engineered hardwood floor over a concrete slab (house built in 70s). The wood is 1/2" thick 7" wide engineered Oak by Somerset. I was originally planning to glue down because thats how the pros do it and I wanted to do it right. I found Bostik Vapor Lock adhesive at a good price and was about to purchase. Then I pulled up some carpet to take a look at the slab and found that the slab is nice and flat but also very smooth. I did the water drop test and while the concrete did darken around the water drop, the drop itself remained beaded on the surface for a while. So, I don't think the slab is sealed, but the top layer is very nonporous.

At this point I took stock of my options: 1) mechanically abrade surface to get a csp 2-3; 2) chemically etch the surface; or 3) float instead of glue.

Option 1 kinda intimidates me. There is a tool rental business just down the street from me that has a couple concrete grinders but it just seems like the process may need a more experienced hand to get the finish right.

Option 2 seems a little more straightforward. I found some products by Surface Gel Tek that seem a bit more controlled and easy to apply than muriatic acid. Their HD24 Pregrind created a 100-80 grit surface which is about a csp 2-3. Their Tek Gel makes a 120 grit profile.

Option 3: My main concern with a floating install is the noise/feel of the floor. I have read that the higher quality underlayments can make the floor sound as if it were glued down. If I got this route, I think I'm going to go with the Floor Muffler Ultraseal.

Questions:
- What option would you go with?
- Are there different products that you would recommend?
- Would the acid etch be effective enough?
- I can't find many reviews about about the Surface Gel Tek products, any experiences?
- Can I replicate or come close to the sound/feel of a glued down floor with a floating floor with the right underlayment?

Thank you so much for any help you can give.

 

Welcome to the forums! If it were mine, I would install 3/8" (at least) full engineered click lock flooring. Fast, simple, clean (as opposed to gluing), and it wears well. I would not glue flooring to concrete as I have found it best to let it float. With proper underlayment, it won't have that "clacking" sound/feel that laminate has. Be aware, too, some vendors are selling MDF/HDF cored flooring and hawking it as "engineered". It is not. Engineered flooring will look like skinny plywood with layered cross sections of real wood.

Time to go shopping. Make note of your likes and post them here so we can help you with your final decision. Not that we would have the final say, but any input can help make the decision easier.

 

You perform a water vapor test by taking a plastic garbage bag and taping it to the concrete and leave it for a couple of days. Remove the bag and see if the concrete has darkened or if there is condensation underneath the bag. You check for a sealed stone (such as granite countertop) by seeing if the water beads up when a drop is placed on it. You can also get a moisture meter and test in various spots around the house.

I would steer clear of glue down. Wood should not come in direct contact with concrete unless it is pressure treated. Leave the acids and scarifying equipment on the shelf.

Floating engineered would be the best option in your case. Click lock engineered is the most DIY friendly and can actually be fun to install. Your underlayment must be one of those approved by the flooring manufacturer or it will void the warranty. Thicker is not better as excess movement can damage the click lock mechanism. You also need an underlayment that is also a vapor barrier to go over concrete.

Do you have a specific link to your actual wood selection?

 

Thanks for the replies. I really appreciate it. Here is a link to the floor I'm getting: 7 IN. Somerset Wide Plank by Somerset Hardwood Flooring. Its Somerset 7" wide by 1/2" thick, 8-ply, .125" wear layer.

You both seem to prefer floating floors. How is it better? Longer life-time? easier to fix? What underlayments have you had success with? I am leaning towards Floor Muffler. What do you think?

I'll be glueing the tongue and groove joint. Any recommendations for the glue would be appreciated.

 

Very nice flooring and in a good design/size. Floating as in click lock is what I was referring to. I don't like to glue flooring down, nor do I like the mess of gluing the T&G. HOWEVER, your flooring is substantial enough for direct stapling/cleating through the tongue.

Floating floor will allow for expansion and contraction which is inherent in wood products. If acclimated properly you won't have a problem with the staple/nail down process. As far as underlayment check with the manufacturer to make sure the underlayment you choose won't void your warranty. I like Roberts with the white dots, but that is a personal choice.

 

In the flooring department of the big orange store, as for Roberts Engineered Flooring Glue. It comes in a round tube with narrow spout for getting the glue well into the groove of the plank. Even though it looks like elmers glue, don't be tempted to substitute as elmers is not rated for flooring.

The glue goes in the groove of the plank to be put down next. The previous plank already on the floor is dry on the outside before the glued groove is set. However, links to your flooring only state that "detailed installation instructions are packed with your flooring", which makes it hard to verify exact techniques required by the manufacturer. So it is possible that the recommend glue placed on the tongue, which would be a little messier. Have a wet towel handy and temp. hold the planks in place with blue painters tape overnight until the glue sets up.

It also looks to be random length pieces, the largest of which is 6.5ft. You will only get a couple of those so learn to weave the abundant smaller pieces so the the joints are always offset by at least 6". Will be tricky given the amount of 12" to 15" pieces you will be fed.

Approved underlayments only. Thicker is not necessarily better. Underlayment must be vapor barrier as well as sound deadening. Secure the seams between underlayment pieces with a good quality duct tape.