What was the cost for SUBFLOOR PREPARATION???? What was the type of subfloor surface upstairs??? Real plywood or some form of OSB/particle board?

What size/product did you use for hardwood? What do the installation instructions say when glue down over concrete? Do they require the 'floating' (whaaaat????) before a FULL SPREAD glue???

In many cases the creaking is from the subfloor...but you state that did not happen before. OK...so let's look at THREE things that can cause the creaking:

1. Surface that the wood is being installed OVER TOP OF - that INCLUDES it's flatness rating and the product itself

2. Metal Fasteners can - and will - rub against wood to create most of the creaking sound. Not all but MOST. Nails are KNOWN to do this unless they are properly ringed. The pressure on the nail gun is SUPER important. Did the installers follow the nailing guide (this will require a small amount of flooring to be removed to see what's what...but wait a bit on that)

3. Width/length of boards over a wonky subfloor - if the subfloor was NOT prepared properly then the wood can and will move...because it can bridge distances without needing to be fastened. This bridge then collapses when you step on it causing the edges to rub = noise. Or the bridge collapses and it is the GLUE cracking and creaking.

Now on to the concrete....oh dear. When wood is glued to concrete is MUST BE full spread glue. I'm suspicious as to whether or not this was done. The MAIN THING that causes a rigid floor like hardwood to feel bouncy is a WONKY SUBFLOOR! There it is again! Darn it!

So...If your upstairs used to have CARPET (???am I correct???) then it had wonky subfloor. Carpet hides the WORST SUBFLOOR products on the market. That means the new wood probably needed a better surface to work with. That means SUBFLOOR PREP! And then there are the joist spans. If the house was originally designed/built for carpet (or something else light) then it would have LONG distances between joists...like 20" OC (on centre). That type of expanse might be too long. And it might mean you had to STIFFEN the subfloor....like with more plywood. You would KNOW if they added more plywood! Did they?

And then the subfloor had to be flattened...lots of sanding/patching...and some patching products do NOT like being nailed through...sigh. If this is all that was needed, (no plywood...just patching/grinding) then subfloor prep should run $2-$3/sf. Plywood adds more.

Concrete prep = +++ work and money. What was on the concrete in the first place? I often tell my clients to EXPECT to pay (ie...budget it BEFORE you purchase the flooring/labour) $2-$5/sf for concrete work.

Again...how much did you pay for subfloor work? What was on the upstairs floor originally? What was on the concrete originally? Do you know the total cost of the project? How many square feet? How much did the wood cost?

Here is my detailed and lengthy response:

UPSTAIRS FIRST - Carpet upstairs originally. Removed carpet in 2016 and husband (who is a structural engineer and a meticulous perfectionist) reinforced the origianl upstairs plywood subfloor with screws due to the fact that the floor squeaked because it had been nailed in originally 29 years prior. When he finished with that, the floor did not make a sound. In the meantime, we remodeled two bathrooms upstairs. In 2018, we started looking for wood floors again but he decided that he wanted to add another layer of GOOD, SOLID PLYWOOD to the existing plywood. Screwed all of it down. The floor was now solid as a rock. And I mean SOLID. And silent. Every single contractor commented on the floor. In fact, even the flooring company and their installer commented that they'd never had such a great upstairs floor to work with. They were "floored" (pun intended) how solid and flat the floor was. My husband did this with the stairs, as well. SILENT. SOLID. And BTW, we've been walking on this plywood floor since 2018 with ZERO noise. I can assure you that the subfloor did NOT need MORE plywood.

The flooring company originally suggested to float the floor upstairs. The they said it would be better to put a layer of tar paper down and attach to that. So that's what the plan was the day they showed up for install. My husband wanted to confirm that noise was not going to be a problem with the suggested tar paper install. Floor company said it would not. And it would be better than floating because it would feel much more solid. Great. We're good to go. Flooring rep leaves and the installers get to work. A couple hours later, I'm told that the flooring rep had called the installer and told him to scrap the tar paper and use glue (the Mapei) and nails. He had decided that would make it quieter and even more solid. OK. So that's what they did. No idea how much glue was used up there because it's not in the quote since they changed the procedure day of install. But I've got 609 sq ft up there.

The hall feels solid. Two of the bedrooms are mostly solid. One bedroom is creaky (not squeaky). There's a difference. No idea about metal fasteners. No idea about following the nailing guide. I didn't watch over them and I wouldn't have known whether they were doing this right or not. They're the "professionals". Although come to find out, 2 of them (young kids) do not do this professionally. One had been laid off from his original job back last March when COVID hit. I don't know what the other kid did beforehand. I found this out on the last day they were here. These two were mostly unsupervised because the "head installer" was busy working on the stairs.

These engineered floors are 7.5 wide. Four lengths. Of which they used 90% long boards and used the mediums to cut and place around edges. And didn't use either of the two short lengths. I made a post about this 2 weeks ago. And this is the reason we ran out of wood and don't have enough to finish the job. If I had purchased the wood on my own (without having them install it, the wood by itself would run me $10/sq ft. Since I had them install, the wood by itself was $6.69/sq ft plus install, plus glue, plus float. We paid $1000 for the glue to cover the downstairs. The master bedroom did not get floated and did not get wood because we ran out of wood. $800 for float downstairs. I told you earlier what was used. Downstairs is 694 sq ft of wood (again, this includes master bedroom). Total area of wood is 1303 sq ft. Floor company ordered 1454 sq ft. Total cost of project is right at $21,700.

DOWNSTAIRS - Originally carpet over slab (I live in Houston). I have no idea about full spread glue. What I showed you is what they used. It also has a moisture barrier in it. They floated one day. Came back the next day and floated again. Started install the following day. Now my guess is that they did not get the floor flat. And I just noticed that the boards that run up to the fireplace all have jagged edges where they cut and the gap between edge of board and fireplace is not consistent. We told them we were going to caulk that edge (no 1/4 round). It's not caulkable now because the gap is so wide in some places it would ridiculous.

STAIRS - Didn't use engineered. Used solid white oak treads. Used white oak on the 2 landings. Totally silent before they touched it. Now every tread creaks.

I don't know what other information you need but I wish my husband had just installed this flooring himself. There are too many hollow, spongy boards to count. Sigh....

One more thing (not sure if this matters) - maybe a better way to describe the sound is crackling. Maybe not so much creaking.

Here's the glue that was used:

https://www.mapei.com/us/en-us/products-and-solutions/products/detail/ultrabond-eco-985

And I'd also add that the original plywood to the house is 3/4". Then, a floor company floated this floor in Oct. 2016 but the wood didn't work out. Then 2018 husband added 1/2" plywood. Good plywood. Not OSB.

OK...you have a floor that MUST be glued + nail/cleat/staple when installed over top of wood subfloor. The 'flatness' of the solid plywood (I believe you...sounds great) is still a question. The sanding needed to be done....and the patching the hollows still needed to be done. The rigidity of the subfloor is not an issue...how FLAT (not wavy) is now the issue. You will need to follow up on that.

The DOWN STAIRS on concrete is going to get ugly. And the amount of glue needed is going to be astounding. You say you have 700(ish) feet down stairs. That means they will have required 24 gallons (6 tubs of 4gallons each) of adhesive just for the down stairs. The upstairs is a different beast. You will have to have someone explain the amount they used upstairs.

I know the Mapei ECO lines. They are NOT MOISTURE BARRIERS. They can handle A SNICK of vapour coming out of a slab...but it says right in the link you sent, "...moisture-controlling wood-flooring adhesive" . Sorry this is confusing, but 'moisture controlling' is not full vapour barrier. The Mapei is NOT to be used a a vapour barrier (like plastic sheeting over concrete).

You can find the proper instructions in this link:

3000291-ultrabond-eco985-en.pdf (mapei.com)

It states for flatness: "Substrates must be flat to 3/16" in a 10-ft. span (4,5 mm in a 3,05-m span)."

That's why the flattening of the concrete NEEDED to happen....and the wood subfloor needed it as well. It it isn't flat...the glue will break it's bond and it will start to make weird noises.

Your concrete needed to be CLEANED (no glue allowed), and cannot be 'smooth' (like poured concrete looks like underneath carpet). It needs to be roughed up. It states in the Mapei technical sheet (which I provided in the link).

Here's what it says about concrete substrates:

"Concrete surfaces must be porous and have a light broom finish. Do not install over extremely smooth, nonporous or glass-like concrete surfaces. If the substrate is glass-like or non-porous, it must be mechanically profiled and prepared by shotblasting, sandblasting, water jetting, scarifying or other engineer-approved methods to an International Concrete Repair Institute (ICRI) concrete surface profile (CSP) of #2 to #3. Note: Diamond grinding is an approved method for subfloor preparation in small areas that are not accessible by the methods mentioned above."

A MOISTURE BARRIER adhesive must be used for slab-on-grade. The Mapei probably isn't the right one for a home that is 29 years old. I love it...but it isn't the MOISTURE barrier that is needed.

For that, they needed to work with a different adhesive. Those guys cost $2 - $3 per square feet.

I think you need an NWFA Certified Flooring Inspector to prove that the company owes you a new floor and owes you PROPER installers.

www.nwfa.org

That is exactly what was ordered - 24 gallons of glue for the downstairs. 6 buckets/4 gallons per bucket. Everything I've read and am reading says the 985 blocks all moisture from concrete. Instructions say it's suitable for concrete (at least 14 days old) with an appropriate moisture barrier properly installed BENEATH the slab. My guess is that they used close to the same amount upstairs. As far as the installers go, I'm pretty sure we got the bottom of the barrel. But they were told what glue to use by the floor company. The lead installer was very familiar with the glue. And this company has been in business here in Houston since 1965. Most of the homes here are on a concrete slab so I'm guessing this isn't the first time they've used this stuff. They floated (flattened) the concrete floor. Took 2 days. They had a 10 ft. thing they used to flatten it and spread the float.

Sorry but the Mapei Eco 985 does NOT block moisture from a slab. It clearly states it is not to be used in situations with hydrostatic pressure (moisture moving through the slab). It's on the second page of the link I sent you.

"Do not install in areas with known hydrostatic moisture problems."

That's where I KNOW it is NOT a full-on vapour barrier. There are very few adhesives that are FULL vapour barriers. The ECO line isn't one of them. And yes...I've met some of the guys who work for Mapei. They are some of the COOLEST, NICEST building-science nerds I have ever met! They are extremely enthusiastic about their work. They are passionate and compassionate.

A 4 hour presentation on moisture mitigation at their headquarters can easily turn into a 10 hour day talking about 'systems' - with everyone moving to a steak house to continue the conversation.

Sigh....but I digress.

The glue is only ONE factor in a chain that has 5-6 moving parts. First you have the concrete and what sits underneath the concrete. Did they test, using IN DWELLING moisture meters, the moisture content of the slab? How long did it take them to do the test? Hours? Or Days?

Then there is the glue. Just because it arrives on site doesn't mean your worries are over. Then you have the TROWEL. It must be PROPERLY USED. Then you have the 'set up' time (Mapei = 1-2 hours...depending on conditions). Then you have the APPLICATION of the wood planks INTO the glue*****. This is where the 'floating' part is weird for me. Normally each plank is set INDIVIDUALLY into the glue.

Then there is the 'coverage' of the wood. The wood should show 95% coverage on the bottom. Which means the installers HAD TO KNOW to pull up the occasional plank to LOOK to see they were doing things appropriately. And pulling an individual plank is HARD when you have GROUPS of planks 'floated' together!!!! See where I'm going with this???

The FINAL piece of the puzzle = the INSTALLER him/herself. You stated there were some young'ens at the job site, yes? And that they were not supervised very well, yes?

Sigh. That means the 'proper' trowel and the 'proper' technique and the 'proper' application of everything was missed. Which is the same as Improper Installation = 100% fault of the company who sent these kids (and said supervisor) out there.

Please reach out to the nearest NWFA Certified Flooring Inspector. I have a STRONG suspicion you have 'floor failure due to improper installation technique' (ie...the dudes ruined it).

www.nwfa.org

And P.S. to the above - the original plywood to the house (1987) is 3/4" plywood and has tongue and groove joints. 1/2" plywood was added to this in 2018. The first flooring company that came out in 2016 got as far as floating this floor. They floated all 3 bedrooms but did not float the hall. The recent company that came out 3 weeks measured for flatness but I do not know what that measurement was. I do know that he said the hall was not as flat as the bedrooms and so they weighted that hall floor down overnight. I know they did not do anything to flatten the hall floor. But the hall floor is the most solid up there.

The last day they were here we asked him how the wood was to work with. He said it was great but he did say there were a lot of boards that were bowed. I'm guessing those were the longest planks (and the only lengths that he used). I guess he put down bowed boards but never did I see that he weighted those boards down with anything. Now I'm wondering if the boards that are sounding hollow downstairs are the ones that were bowed.

Well, we sent the flooring company an email almost 6 days ago and haven't heard back. My husband talked to Mapei today for almost an hour. They were very helpful.

It can be the open time on the product. The installers might have gone over. Which allowed the glue to skin over and not adhere, allowing movement.

Who knows. I think we have a whole host of problems now. Don't even know where to begin or how to proceed.

Contact a NWFA inspector. They can consult you over the phone.

We contacted an inspector today. Yesterday we found out through our phone call with Mapei that the installers did not prep the concrete slab correctly before they put the float down. They should have prepared the slab and then used the primer T (pink stuff) and then put the float down. Then they should've put more primer down the 2nd day they floated. They didn't do any of this. They also should have waited at least 24 hours before they started putting down the wood if the float was 1/2" thick. They didn't do this either. They were putting wood down 16 hours later.

The wood we purchased is thicker than 1/2" and the trowel they used for the glue was for 1/2" and below. So they did not use the correct trowel upstairs or downstairs.

I'm guessing this floor company doesn't follow any of these slab preparations. There was no money in the quote for a primer to be put down. Or any kind of acid wash before the primer went on. So my guess is they just never do this. They come in and float and call it good. Maybe this is ok? I don't know. I guess they just use the same trowel for every job they do regardless of how thick the wood is.

We spoke with the inspector over the phone today. He said they didn't prepare the floor correctly. He said that 15% hollow places is acceptable. We haven't calculated the percentage of hollow boards. He did not say if any of this is going to cause problems down the road. He'd have to come out and then do a report. But again, I'm willing to bet that most companies do not prepare the slabs correctly here. The last flooring company we had come out here did not have any primer in their quote. And nothing about preparing the slab for float. So I don't know how big a deal it is. What I do know is that our back family room is solid as a rock with zero hollows for 10 years. But it's also 1/2" thick so the proper trowel was probably used. My guess is that there's not enough glue on our new floor since they used the wrong trowel. And how big a deal is this going to be upstairs glued and nailed to the plywood sub floor? Getting that off of there will completely destroy the new plywood my husband painstakingly put up there. Who pays for that? Who has the capability of doing it right? arrrrrrhhhhhhhhhhh

Oh dear. That's what I thought. Here's the skinny on 'prep'. Prep is the UGLY stuff that NO ONE sees and NO ONE knows to ask about...nor do they usually OFFER the ugly stuff in their quotes.

The ugly stuff is expensive. And in the past they have quoted it and they have lost jobs to lower bidders who did NOT offer prep. Over and over again the 'good' companies offer quotes on prep and time and time again they LOSE the jobs.

So they have started to work like everyone else. To stay in business they drop the preparation quotes. Which is how they get jobs....because their bids are now 'in line' with the companies around them.

Subfloor prep needs to be paid for. And the company that promises it must deliver it. The basis is, you pay for it = you get it. This company has not quoted nor were they paid for prep work. Sadly (oh so sadly) you were the one who 'got what you paid for' (not meant in a mean way).

So...to get preparation done, you will need to pay for it. An upstairs preparation costs = $1-$3/sf for a bit of sanding...a bit of levelling...a bit more sanding.

The concrete slab can require $2 - $5/sf for preparation...and in this case the sealant will need to be paid for as well. A slab that is in good shape that is nice and flat, that only needs a good scrub to get a bit of bite to it = $2/sf.

A concrete slab that needs a good cleaning (may have old carpet glue all over it) and plenty of grinding and plenty of patching (Self Leveling Compound = SLC) and more grinding can and will cost $4+/sf.

And these numbers are why they didn't quote it. The upstairs = $2/sf x 609sf = $1,218. The downstairs concrete (just for fun we'll use $4/sf) = $4/sf x 694sf = $2,776.

The prep alone *should have been quoted at $4,000. Their quote should have been more than $25,700.

***At this point, assuming you can prove they were all wrong on all things, they owe you removal of the improperly installed floor. They must replace with 'like for like' subfloor plywood that was there BEFORE they arrived.

Be aware that you *might be required to pay the extra $4,000 for the subfloor preparation that you did not pay - that needs to be done...you may not. It depends on how good you are at negotiating.

If they won't do this voluntarily you will be required to pay for the NWFA Certified Inspector to come out and document what you spoke about over the phone. And then you present the findings (but do NOT hand over the document...SHE who pays for the report OWNS the report). The findings will push them to do the right thing.

Hopefully they will come to their senses before you have to spend several hundred dollars on the Inspection.