I’d let it slide this time. If it comes up again and hopefully it doesn’t, remind him of the contract and what you agreed upon.

Subfloor removal/preparation is ALWAYS a 'best guess' and should always have a 'range' of costs such as $1/sf - $4/sf depending on what the contractor discovers at time of demolition. Two layers of flooring instead of one is always an option when working with an older home. This doesn't bother me too much.

The adhesive is one I'm interested in. The contractor believes a thicker plank needs more glue....hmmmm...interesting way to get the customer to pay for the glue that is required by the manufacturer.

How is the floor being installed? Full spread glue down or a Nail-in-place with glue assist?

I'm going to assume the installer thought a nail-down with glue assist (a snake of glue over the back of the board) was what s/he was bidding. Only to find the actual install is a full glue down install (there for using HUGE amounts of adhesive adding MASSIVE amounts of costs). Does this sound about right?

Has the subfloor preparation been achieved? If so, how much did you pay for it and what was done? Again, a floor that has had TWO floors removed is going to need ++repair. A new layer of plywood may be needed....it may not.

Is this over wood or is this over concrete slab foundation?

There is nothing interesting or special about your story. Happens all the time.

You should have had an all-in price quoted, and that's the amount you pay.

The contractor did not disclose all the necessary information to you regarding your project. Normally when all the details are included in the proposal. The total amount is outrageous. The project was out of your budget to begin with.

Review your contract and see what type of adhesive and how much is already included. If, the correct quantity is already included, then hold him to the contract. While you're at it, see what you might be missing.

Removing two layers of flooring will mean that your house has planks for subfloors. To do a full spread glue and nail assist installation. You will need a layer of 1/4 or 3/8" plywood subfloor to prevent roll-on and glue from dripping downstairs and 1 or 2 coats of roll-on moisture retarder (depending on RH and MC).

How wide is the flooring?

You should be thankful Mr. Low Bidder is at least aware of and passing the costs of what should be done onto you.

Now he tells us we have to buy the glue because of the type of the engineered wood we want to use, since it's thicker and he has to use more.

So you check up on him. What is the exact flooring? Pull up the installation instructions. Calculate how much of the recommended adhesive needed & price it yourself. Then select another brand of flooring/ thinner engineered product & do the same.

When was the flooring selected? Before or after the job was quoted?

The contract states he will supply and install all the need materials, but we will pay for the flooring and underlay.

Arguablepoint, I suppose, that the glue is part of the 'flooring and underlay' and the furnished 'material' is fasteners. Especially when you hire the low bidder. And when you don't specify at the get-go.

Reminds me of a song, "We've only just begun"..............

Please post the name/line of the wood floor you have chosen. A link would be even better. And what is the substrate it is going to be put over? Plywood or concrete?

It will be on concrete (it's a condo), and we picked the Grandeur Thunder Cloud maple engineered wood 3/4 thick to be glued in top of cork.

He thought we just were getting a floating engineered wood and nothing needs to be glued. We never told him that and there were no details of that in the contract. He thought it was going to be 1/2'' thick and he wouldn't have to glue anything at all. The contract doesn't specify glue as our expense, just the underladyment and flooring. But he says we have to pay it.

He assumed and you assumed- it happens. Either you trust him at this point and pay the additional (FYI flooring glue can be REALLY expensive) or now armed with your final selections you get more bids on install.

He thought it was going to be 1/2'' thick and he wouldn't have to glue anything at all.

Vs. over $3 per sq ft just for glue for the hardwood. Plus labor to spread the glue. Plus the cork will have to be a full spread glue down. Can't do loose lay or perimeter glue the cork.

Also, is this below grade, on grade or above grade slab?

A floating engineered hardwood needs glue on the tongues. So that LITTLE bit of glue would have been expected (on his side). A glue down hardwood is one of the more expensive installs we have. The glue can be astronomical. And if s/he has to glue down the underlayment (like cork, etc) then there are TWO layers of glue....not just one.

What type of 'underlayment' are we talking about? Is it plywood (sigh) or is it an acoustic underlayment like 6mm or 12mm cork?

Cork underlaymen, SJ. "we picked the Grandeur Thunder Cloud maple engineered wood 3/4 thick to be glued in top of cork."

IOW's lot$ of glue. I would reverse course & look for something else that didn't require such an expensive install.

Thanks ci_lantro...I just reread the OP's last post. Yah...the cork is going to need the SAME amount of glue as the floor. That means a DOUBLE stick...Ohhhhhh dear! That's very expensive.

Personally I would find an engineered floor that is allowed to be FLOATED. That will save you $$$$. The cork is 'floated' (it just sits there...nothing needs to be done to it) and then the floor would float over top of it. The amount of glue will DRASTICALLY reduce and the amount of LABOUR will drastically reduce.

The $1000 up charge would go away. Or a little bit more money would be spent on the subfloor preparation (probably gypcrete = super annoying to deal with) so that the floor sits beautifully over the floating cork.

I'm sorry to say Lana the installer would have quoted you properly if s/he had been fully aware of your flooring + underlayment decision. In other words you would have said, it must be glued down and cork used underneath. The GC/installer would have quickly understood the double stick idea.

I'm going to tell you a little secret about cork and glue. You need a regular amount of glue to get the cork to 'stick'. But you need MUCH MORE glue to get the wood to stick to the cork. Why is that? Because the glue on TOP will simply 'sink into' the cork underlay. That will leave very little glue sitting on top. The cork will just suck the glue right into which means the installer will trowel on MORE glue than the 'bucket' says. Which means the $1000 up charge is going to turn into $1500 very very quickly.

If your 'guy' hasn't done this before, he won't know to add MORE glue to the cork. He'll find out somewhere around 30% wood installed. He will them have to come to you to purchase MORE glue...and that's when your project will skyrocket.

And another thing...doing a double stick like this adds 2-3 DAYS of time onto the floor project. Why? Because the cork layer must CURE first. The guy cannot go over a wet cork. He'll have to wait until the first layer of glue cures. That means more time spent OUT of the condo. If you are in a hotel/motel, you will have to pay MORE for those extra nights.

And if your 'guy' doesn't know this, he might request more money because of his wasted time 'waiting' for the first layer of glue to cure.

Again, this is where I would SERIOUSLY look at a floating floor over floating cork. I'm unable to find installation instructions for the Thunder Cloud Maple (wear layer is only 2mm...which is strange for such a thick plank). I would reach out to the manufacturer and ask for the installation instructions for your choice. And while you have them on the line, go ahead and ask if your choice can be floated. And ask which GLUE is required for installation.

Update: he told us he simply can't do the full glue down due to unstable humidity and he can't give us the warranty for the job because the floor will crack and cork will rip apart.. So we looked for the click floor vs tongue and groove. There is very little selection and we didn't find anything we liked. Some floor places said that tongue and groove floor can be floated and just glued on the sides of the planks. We think he won't do that either.. We checked the humidity and without humidifiers it's below 10%. Now it will be higher once we move in. Can either type floating or glued down engineered wood flooring sustain this? We really don't want laminate or vinyl. thank you.

Is the slab below ground level, at ground level or on a second floor? Have you had the slab tested for moisture? What is your general geographical location?

It's a condo. Why type of flooring do your neighbors have?

What type of flooring does the contractor suggest?

Will the HVAC system maintain proper humidity levels 24/7/365?

Below 10% humidity? Wow! That is SUPER dry! Laminate is all I would suggest. Are you in a hot climate by any chance? Vinyl won't work in a condo...it can't be installed over cork or any other type of acoustic underpad. And if you are in a hot climate vinyl will have HUGE issues with warping in sunlight.

If you insist on hardwood, you need to go AS THIN a width of plank as possible. The 7" plank is SUPER dangerous in dry climates. And a thin wear layer (2mm is thin) you are almost guaranteed it will crack and split.

I HIGHLY recommend you thank your installer for NOT doing this. You have found a 'decent guy'. Yes it surprised you with the additional glue, but it turns out he's done you a MASSIVE service by REFUSING to do what you want. That's worth THOUSANDS OF DOLLARS in my book.

The flooring manufacturer stipulates the installation for each and every floor. Not all engineered floors are allowed to be floated. Not all are allowed to be glued. You will have to work with a floor that can be floated...and in the THINNEST plank width possible. There are plenty of 3" wide engineered planks out there.

Your humidity is your BIGGEST issue. Personally I think laminate or HIGH END porcelain tile install (thousands of dollars more than a double stick wood floor) will work. Vinyl probably won't do it because of the noise concerns with the condo board. Vinyl is STUPID tricky to get into condos...'cause no one can get them to be quiet.

We are in a cold northern climate, and it gets pretty dry in the winter, but not so much in the summer. We are on a high floor and some ares are exposed to the sunlight in the morning which will be covered by the shades. We did tell the board in writing we are doing engineered wood not sure they'll approve the change. And we are required to put an underlay for the sound proofing.

Yes...I get that. The hardwood has the same acoustic rating as laminate. Both of them require the same amount of noise abatement as the other. And tile also requires this...but with a bit more cork (like 1/2"...which makes floor heights ridiculously high.

And vinyl has issues with A. Direct sunlight and,

B. Acoustic underlayment. it is almost impossible to get the right amount of underlayment underneath vinyl. It really should be reserved for single family homes.

So you are down to:

1. Laminate floating floor with 6mm or 12mm cork underlayment

2. Cork floating floor with 6mm cork underlayment

or

3. Hardwood (engineered or otherwise...it doesn't matter) that is either floated or glued to 6mm or 12mm cork underlayment.

Where are located?

4. Carpet (and yes, no one wants to hear this.) :-)