Floating Laminate floor question
 

Hey all,

I'm installing a new floating laminate floor in our sunroom. Its a concrete slab. Along with it I will be doing electric floor warmers so naturally due to the warmers and concrete there is a vapor/insulating barrier on the floor first.

So my question is - the floors we like have a 2mil attached pad preinstalled on them. Is it okay to have the underlayment and then install a floor with an additional underlayment? (4mm total)

I don’t see why not. As long as you have a solid and reasonably flat substrate the floor doesn’t care what it is installed over.

It will be fine. The more insulation the better

What system are you using under the floor?

Are you using Floor and Decor? I se there are stores near you. We like NuCore, and strongly do not like AquaGuard. As in will never use again.

For our downstairs bathroom we used Ditra covering then heated flooring and stone. This allows the concrete to breath as well. I’ve never been a fan of plastic right on concrete due to its’ porosity.

I’m using quietwarmth electric. Very thin system.

As far as flooring Were looking at mohawk/pergo.

Underlayment is roberts air guard. Breathable but with a vapor barrier

Check how water affects the laminates you are looking at. Some brands tend to act like a sponge and the edges swell when wet and then look like crap.

My Pergo does fine. I used a different brand (don't remember the brand) in a small sunroof that was terrible.

Well unless you buy vinyl they are all “water resistant”. . The room is dry and the underlayment is designed specifically for below grade concrete floor.

Vinyl click lock would be good if I expected a lot of wet, but part of the rehab was all new windows, weather sealing, and is above grade by 12”

Some of the underlayment pads are designed to allow some airflow, routing away any moisture.

Chris
I've been thru lots of floors in my concrete slab home over the years,from real wood to engineered wood / laminate. We finally installed the LVP (luxury vinyl plank) over a moisture proof paint & a 4 mil visqueen vapor barrier. I highly recommend it. It is scratch proof, water proof and beautiful. Make sure you go with a high quality/name brand whatever floor you pick. There is a lot of questionable flooring being sold.
Dave

Thanks. My logical side tells me thats a better way to go...

Recommend the 10 mm thick stuff. It seems to lay better and the joint edges are larger too.

Keep in mind that the thicker the underlay, the less efficient the heating source above the slab will be.
10 mm - you might not feel the heat at all ?
Bill K

I vote LVT, it looks better than laminate, is not slippery like laminate, is water proof unlike laminate. And, unlike any laminate, the good stuff carries a life time warranty. Use any mil visqueen (loose layed). Though LVT is waterproof, it blocks any possible hydrostaticaly transferred mineral buildup that can come from the slab up through the seams of the planks. I've seen it happen. The electric radiant heat mats lie on top of the visqueen and I would recommend a cushioned backed LVT product on top of that. A forever floor.
Of the many disadvantages of laminate, the biggest problem is water from the top not the bottom. Potted plants, pet water bowls, heavy mopping or a plumbing leak. Ponding water will find its way into the seams and swell the particle board or MDF core material and the seams are puckered forever. This will not happen with LVT.
I stopped selling laminate 25 years ago, too many call backs that were not my fault. My guys will install someone's laminate they bought elsewhere but not without signing a waiver of our responsibility for what happens down the road to their crappy floor covering. I'm a licensed flooring contractor in CA with 50 years experience for what that's worth

I would talk to the manufacturer of the laminate. Laminates aren't all the same with regard to adhesives, etc.

Excellent post.

Wood laminates are really coming back to haunt people that put them in 15 years ago or so. Agree with everything said above.

Call China?
Laminates are all manufactured using copious amounts of adhesives causing the product to gas off formaldehyde for years. LVT is not made this way

What’s the difference between LVPlank (click lock) and LVT?

LVP is a longer "plank" . LVT is square or rectangular "tile". Same material.

LVP is the same as LVT, just in wood plank form. The stone look Luxury Vinyl Tile is usually in 1'x2' tiles. I usually install them Roman style with butt joints splitting the butt joints of the last course. More waste this way but a good look.

Thanks. I assumed so, but I didn't want to assume so. :)

Make sure your floor is flat.
Otherwise it will click and you will end up pulling it up to level it.
Ask me how I know.

Yep thanks. Its poured concrete so pretty darn good.

How much does thickness matter?

6mm vs. 8mm for example?

So was mine. It only takes a little dip.

Industry standard discrepancy is a quarter inch in ten feet. Flatter is better of course but click together is pretty forgiving. High spots are more problematic than low spots. A poured slab is generally not as consistently flat as a suspended wood sub floor. It all depends on how well they troweled it. A quick flash of Feather Finish patching concrete on low spots is easy. Don't use a gypsum based floor stoneing, always a Portland based on a slab.

Glue the stuff down, or it will make noise when you walk on it.
Not a fan.

^ not true if done correctly. Floating floors work better than adhered when done right. The loose layed method also eliminates a lot of prep work. The biggest mistake do it yourselfers make is not allowing a quarter inch expansion gap all the way around. When it's all clicked together it becomes a monolithic unit and will expand a bit when summer comes around and can lift the flooring off the floor. Undercut all door jambs and don't cut even one tile tight to the wall

How is the concrete guy getting the floor flat? Our guys use a power trowel and it seems like we are always going back and forth with the finisher and installer trying to get it flat. Concrete guys says it's within his specs and the installer says no. Of course, the installer doesn't want any call backs and wants it flat as glass.


We always leave a gap for expansion and contraction around the room.

It's very rare that I run into a slab that I don't have to fine tune. I just do it myself with Feather Finish. Great stuff, ramp it to 0 and it doesn't crack. For the glue down LVT the substrate has to be like a baby's bottom. The floating click together, not so perfect. We love the click! it's a money maker for installers

Are you grinding the high spots with a big walk behind machine or hand held?

I’ll bet. The installers can install 1,500 SF in a day.

Grinding is rare. It's messy, expensive and certainly not a fun job. Cutting humps out and pouring self leveling concrete is more common than grinding but it's got to be a pretty badly poured slab in the first place to have to do that. Most times I can doctor up a slab without grinding or cutting by using a self leveler or patching compound to get it to spec. A spinning laser helps.

No doubt grinding sucks. Dust everywhere and needs to be done early in the build process and the installers won’t do it.

I think you guys under estimate my willingness to put up with a little bit of floor unevenness in a sunroom. :)

I'll check it with a straight edge and call it good.

My vinyl plank floor walks perfectly, no noise, no clicking like the original Pergo laminates. My previous wood laminate was very spongy and the dark cherry finish showed every bit of dust and dirt (not to count the dog or cat hair) it was awful. Also if you have existing base down already it is a good time to rip it out and put a wider base down. It eliminates the shoe mold and looks much richer.
Dave

That's just it, you're not building a watch here . A teensy bit of imperfection ain't no thang. When after all said and done no one will notice a floor that's a quarter inch out. I try my best to do as perfect a job but within reason. No house is perfect and you just work with it. Don't sweat the small stuff, it'll be beautiful in the end

http://forums.pelicanparts.com/uploa...1608663640.jpg
Here's a house I'm working on at the moment. They're up to $20M and counting. And believe me us finish guys are dealing with plenty of little imperfections, that's just normal in construction. A good craftsman can make a crappily built house look great and a bad craftsman can make a well built house look like crap.
This is actually a really well built place. This is one interior wall with a row of 9' doors. Some people have too much money!

http://forums.pelicanparts.com/uploa...1608665555.jpg
This is my floor during installation

With due respect, my personal experience would indicate otherwise at least when it comes to Nucore Rigid Core Luxury Vinyl Planking (installed by a professional).

Luckily our baseboard trip is near 1/2" thick so I have plenty of room to allow for expansion. I plan on using it particularly since this room will ahve more temp swings than others.