Bump

My husband just put floating floor in his new office (which is on the second floor). He went with a cork backed floating floor. The cork helps with noise, subfloor imperfections and cushion. He's super happy with the choice.

Kitty, we have permission as long as we use sound suppression at 70db or better.

Also wondering how much the floor thickness matters with floating. I would guess thicker is better but maybe it's the opposite?

Another factor is repair costs. Getting concrete to let go of properly adhered wood floors is nearly impossible. I had to machine the adhesive off the concrete. 15lf of replacement boards was nearly a thousand dollars with pre-finished material provided by the homeowner.

ker9....not much survives underneath the crushing weight of a floating floor. Not to mention the lack of air to maintain life. A floating floor, say 1000sf is (roughly) 2-3 lbs per 1sf foot. That means your floor could weight 3000 - 5000 lbs. Not much survives that level of "crush". The lack of 02 also makes it difficult for anything to survive.

And the acoustic rating your HOA is quoting is "absurd" to say the least. Sound suppression of 70 dB is IMMENSE. That would require a concrete slab of 10" - 12" just to start. If your building does NOT have 10" - 12" concrete floor/ceiling assemblies then you won't reach 70 dB. Nothing hits 70 dB.

A 6" concrete slab averages 30 dB. That means your floor + underlay has to have 40 dB. Ooops. The subfloor should make up 60%-70% of your acoustics. They have it bass akwards.

An 8" concrete slab averages 33 - 37 dB. A 10" concrete slab is close to 40 dB. A 12 in concrete slab (seen only in multi-million dollar apartments in NY and LA) averages 45 - 47 dB.

A 12mm cork underlay will offer 22 dB. Add that to your floor/ceiling assembly (47 dB + 22 dB = 69 dB). It is one of the MOST ACCOMPLISHED underlays we have....and even 12mm cork underlay cannot reach 70 dB. Technically your condo board has asked for something that is impossible to achieve under normal circumstances. That makes it "illegal" for them to ask for it. I've already seen several Canadian condo boards taken to court because of this and they have lost. If it is physically impossible for your building to achieve "70 dB" (without causing undo hardship on the owners of the unit) then the rule can be struck down in court. It can and it will be struck down. It just takes someone to file the lawsuit.

I would guess your condo building will require 12mm cork underlay or 8mm solid rubber (stinks to high heaven = intensely expensive). They sound like one of the "uneducated" HOA boards working with "out of date" industry standards from the 70's that "look good on paper" but are completely out of sync with today's understanding of material testing.

Have fun. Work with 12mm cork underlay under a floating floor. You will be fine.

Cancork, thank you for the information, it is helpful. FYI: a rating of 70 stc or above is typical for Florida condos. Floor muffler and Proflex 90 both meet the sound requirement.

@ker9 - if you read the testing document for Floor muffler and Proflex 90 you will notice that they tested the things with MASSIVE concrete slabs (10" or even 12" slabs), thick "wood" floors and the ever familiar (but always missing) "drop down ceiling". All this adds up to "72". I see this on a daily basis.

This is common practice to "inflate" the value of the underpad by using thousands of dollars of someone else's material (Armstrong Drop Down Acoustic Ceiling = $10K just to use in the testing facility) and then to publish the WHOLE THING as if one little scrap of 3mm material will "eat" 70 dB worth of material.

A drop down acoustic ceiling adds 14 dB to those already inflated numbers. That's how they reach "72". Nothing else can get you there except the drop down acoustic ceiling. That is more than the "acoustic underlay" itself. Not many people will purchase a $10,000 acoustic ceiling for their DOWNSTAIRS neighbors.

I would say 99.9% of STC/IIC ratings are bogus. Just be aware. Ask for Delta IIC ratings for underlay. They cannot be manipulated. They are as "pure" as we get. And they show how little the actual underlay offers once all the "extras" are stripped away. Which is why many manufacturers will NOT test their underlay using the Delta IIC rating. They don't want a document showing how BADLY their underlay performs. They already know how poor it performs so they don't even bother testing it to the Delta IIC level.

Good luck.

Du Chateau floors are not interlocking. How does that affect a decision to float or glue? It does state that it can be installed floating, just wondering how that affects things (that it isn't interlock).

ker9 - the edges are glued. So long as the floor you choose (they have multiple lines...not all have the same installation application) is designated as a floating floor, it can be floated. The flooring installer adds glue to the tongue of each plank (the adhesive must be rated for wood flooring and flexible enough so that it doesn't make noise when stepped on) and then the groove is slid into place. While they work, they will use blue tape to hold the floor together (so they planks don't slide away from each other) while the adhesive cures. Once cured (usually 24 hours or so) they remove the tape and give it a bit of a clean. Done.

The install is not as fast as a nail/staple/cleat in place floor, but it is NO WHERE NEAR as timely/expensive as a glue in place hardwood.

Cancork, thank you so much. You have been incredibly helpful and I greatly appreciate it. It's a big, expensive decision.

The particular floor I'm looking at does say it can be floated. I expect that the levelness of the concrete and the underlayment will make a difference in how it feels and sounds.

This discussion is very informative and useful. I'm going through the same decision process - glued vs floating. Am concerned with the "clicking" sound a floating floor makes. Does the cork underlay address that concern? Thanks.

@ker9 - I'm so glad I could help. The floating option will work out just fine so long as the subfloor is dealt with AND the appropriate (read: flexible) adhesive is used on the joints. It will save you a TON of money (as you've just discovered by the recent quote for floating install).

@tsarina94 - the only thing that will "address that concern" = subfloor preparation. That means paying the piper to get a subfloor that is a flat as possible. This work you will pay for but won't "see". You will "hear" the difference. A poorly prepared subfloor = loud, clicky, bouncy, irritating floor. If you pay someone $0.50/sf for subfloor preparation, you will get all the noise and irritation. If you pay someone $3/sf to prepare the subfloor, you will get a close to a perfect subfloor.

Cork underlay will not "solve" the subfloor problem. It solves the "noise of living". It solves the "neighbor complaints". It solves the "cold floor" complaints. It solves a lot of things but it will NOT solve "poorly prepared" subfloor preparation.

If you get a beautiful, flat subfloor and add cork, you will achieve a magnificent, solid feeling/sounding floor. It will feel super solid. The cork adds that "solid" feeling (and eliminates HUGE amounts of noise).

Can cork correct a subfloor that isn't flat? No. That means it, alone, cannot "address this concern". You can save a ton of money by floating an engineered floor. You WILL spend a bit of that savings on the subfloor preparation and the cork. You will still work out to be THOUSANDS of dollars ahead.

Thanks for your quick and thorough response. To summarize, to minimize the hollow sound of a floated engineered floor, the subfloor should be as flat as possible, use a flexible adhesive on the joints/edges of the engineered floor, and use a cork underlay to (1) get a solid feeling floor and
(2) minimize the noise my neighbors hear from me walking on the floor. The cork underlay not minimize the hollow sound of an engineered floor, regardless of the subfloor preparation.

cancork - thanks for your quality input. My contractor used a top of the line, thick underlaying for my floating engineerefloor. It looks, feels and sounds like hardwood floors. I couldn't be more pleased with the outcome.

Tsarina94, what did you use?

My condo association required Proflex R250 underlayment. The flooring is engineered Amendium,, natural smooth 5" boards. Floor is floated. He used the smallest size quarter run, painted to match based boards. Walls and floors were so uneven that baseboards didn't cover all the gaps. I moved from New England to Florida and always had hardwood floors. Im very pleased with this engineered floor. Attached is a photo before the furniture was put back in place. Good luck.

Tsarina94, your floor looks beautiful. Thanks for the update. My floors are on backorder until mid November. If you are on the East coast, be safe!

Ker9 - Contractor used the smallest quarter round (not quarter run) around the baseboards. My preference was that he remove and reattach my baseboards to install the floor. In all honesty, the small quarter round, painted to match the baseboard looks much better than I feared - especially after a glass of wine!