The incorrect color filler was used after the floor was finished. If, they cannot find a matching filler, then touching up with stain should have been done.

The caulking is a cover up for bad cutting, either from baseboards or from flooring.

I agree on both those points and I would not choose red oak if this is the look you want go white oak.IMO red oak will have a pink tone in that light stain. As for the solid versus engineered often it depends on where it is going and also budget

The 'install' itself is OK...but the touch-ups are sloppy. No one should use a white filler on gray planks...after the finish is down. The white filler is supposed to be applied BEFORE the floors are finished...they receive the stain like the rest of the wood and then have poly applied afterwards.

The caulking at the baseboards the installers were trying to 'hide' an expansion gap by filling with white caulking (same colour as the base). The technique is acceptable but the little bit of sloppiness of the worker DOING the technique is questionable.

You have posted photos of the contractor who will be doing this...you are concerned about things that are simple sloppiness. That tells me the guys/gals will rush the job a bit and not pay attention to any 'little issues' until the homeowner complains/demands a solution.

Be prepared to have the SAME issues.

As for engineered hardwood being 'harder' on the body = nope. Wrong. The 'hardness' comes from THICKNESS and what it is SITTING on. A 3/4" solid hardwood (or engineered...don't care which) sitting on a plywood subfloor = not hard on the body.

Whereas a 3/8" engineered (or solid...sigh...yes they are out there) glued down to CONCRETE = hard. Why? The CONCRETE is harder than the plywood. There is NO GIVE to concrete. The plywood under a wood floor has a bit of 'give' or deflection. That's fine. Wood can handle it. But it is part and parcel of a 'more comfortable' floor.

As stated by Patricia above....use WHITE OAK...Pay the extra $1.50/sf more for white oak and get a GRAY that does NOT TURN PINK. Believe me...the quality of the contractor you have chosen is going to suit white oak much better than red oak.

@G & S Floor Service Thanks for your response. I was talking to this home owner, he mentioned that the flooring finish was done in Jan'21. These worn marks started to appear only now in May'21. Just curious, if an incorrect filler color was chosen, wouldn't be visible from the day 1? I was thinking that this might be caused by a poor wood fill job or an improper fill product was used which was not having good adhesion with the stain & finish applied over it.

From your response, I understand I should refrain from caulking the baseboards to the wood.

@Patricia Colwell Consulting Thanks for your response. I am just trying to assess if the contractor's job is good, so that I could give my project to him. My idea is to go with a 5" wider select grade white oak and do a 2 coat Bona Nordic Seal + 2 coat Bona traffic HD.

I am still thinking what sawn type to choose, plain or rift & quarter for a white wash look.

If it helps, I am planning to replace the tile/carpet on concrete slab with hardwood. Below are the things I am considering.

1. Refrain from replacing the entry door thresholds and shaving the doors to match the height of the floor.
2. The dishwasher can be easily removed as the height of the floor would be 5/8" with site finished engineered vs ~1.75" with the solid hardwood.
3. Dimensional stability that comes with an engineered wood at the same time, have it finished on site to give a solid hardwood look & feel.
4. AFAIK, the cost between the solid and site finished engineered is almost the same, with the site finished engineered tends to be couple of hundred dollars cheaper than the solid hardwood.

@SJ McCarthy Thanks for your detailed response. As I have responded to G & S flooring above, the worn off marks started to show up 4 months after the job was done. So I am confused how the wrong filler color didn't show up back then.

I understand now that there is a clear advantage of the solid hardwood floor 3/4" over a plywood as the wood + plywood will have level of cushion factor which won't be there with the glued down 5/8" engineered wood.

If, the issue occurred well after the floor was completed. You have a bigger problem. signs of premature wear or adhesion failure is bad And will require a full redo. You will need to test for adhesion to confirm. It should not wear out like that, even with the lowest quality finish.

@G & S Floor Service Gotcha. Thanks, I will see if I can ask the home owner to test it out.

So this is a floor from someone else that the contractor is 'showing off' and it has EARLY WEAR and BAD filler and sloppy baseboard work? Wow. That's cahoona's. Cheeky devil doesn't even know enough to know this floor is bad.

Walk....away....right....now. A floor that is FRESHLY FINISHED should NOT have these issues APPEAR at 4 MONTHS. Maybe 14 years....but not 4 months. This is a sign of a floor that did not get the treatment needed to protect it for 25 years.

Yes...imagine what this floor will look like in 25 YEARS. Now image YOU have to deal with this 'contractor' (I can't even say 'flooring pro'...it is SOOO WRONG) in 6 months time...and in 8 months...and in 12 months and then once a year for 25 years???

Wow...if this is what you have to look forward to, then hire someone else. Or ask the work is done for FREE...because that's what it's worth.

You are right SJ. Thanks. I wanted to get opinions from pros like you all from this forum, as I couldn't understand if this is a simpler mistake which can be avoided in my project or this is just poor workmanship. Now I am clear. Thank you all!

Good luck. Keep asking questions (may be start a new thread) as you go along. A full sand/refinish should cost $5/sf for a medium range finish. A high-end polyurethane adds $1-$2/sf onto that. The type of install is going to dictate price. The type of wood is going to dictate type of install (solid vs. engineered floating). They colour of finish you want will dictate the stains/finishes you use.

The baseboard looks like it was installed around a high area in the floor. Seen it many times.