I dealt with this as best I could - a combination of the diamond-encrusted screaming wheel of death and a silicon carbide belt on the sander was all it took, and this was all accomplished while this area was wrapped in plastic.
The original plan was to install the new boards with a combination of nails into plywood subfloor, and construction adhesive at the leveling compound...or both for that matter.
The floor went in easily and I weighed it down over night.
This is where it gets interesting, because the next day I discovered that the construction adhesive was a total failure...and this is also where I went back to working on the living room side of the fireplace, covered the mess shown below with a rug, and forgot about it. Well, two-thirds of that is true.....research ont tut' interwebs tells me that I had not waited long enough for the leaving compound to cure...and that the adhesive cannot bond under these conditions.
Today is eight weeks later, so if the leveling compound isn't cured by now, it never will be. I checked the fit of the hardwood flooring after painstakingly grinding all the old adhesive off the back of the boards with the ever-present belt sander.
The boards were then re-installed with more adhesive and nails. I had to bash in the nails in between Amy Sheep's telimedicine appointments.
Then I weighed everything down and went for lunch
Today's lunch - a ham, lettuce and mayo sandwich and an orange if you're interested - didn't take all that long. I didn't want to disturb the flooring, so I concentrated on finalizing repairs to the drywall that was damaged when I installed my security lights.
I also installed new baseboard in the office - we weren't ready to commit to a style of baseboard when we decorated this room.
I think I bought 400 feet of baseboard for the living areas, office and kitchen...whatever it was, it I ended up ten feet short, so the section below the office window was made from some scraps of hardwood flooring which I ran through the table saw.
By now the adhesive had had a couple of hours to cure, so I removed the weights, and discovered....another failure. The sections of the boards which were nailed were secure, but the other pieces were flapping around like a syrup in the breeze.
At this stage I could have tried a third time with an alternative construction adhesive , but really I needed an immediate solution. This section of the floor will actually never be seen, because we will be constructing builtin-in cabinets in this area eventually. So....I took the cowards way out and screwed the hardwood to the concrete pad with masonry fasteners.
The new boards were proud of the original floor by 3/32" in places, so I started with the hand plane - this was hard work, but it would have taken much longer and been more dusty with the belt sander.
I cleaned up the shavings and hung a drop cloth between the dining and living rooms...
Then I taped the hose from the shop vac on to my belt sander and gave the new boards a good going over with a 36 grit belt; working this way produced very little dust into the air. In the future I will be trying to find the right fittings so that I can connect the shop vac to all of my power tools.
Red oak wood filler was applied to the nail holes and those unsightly concrete fasteners.
After that there was just enough time to apply wood filler and caulk to the new baseboards I installed earlier, and then it was my turn to drop unconscious from exhaustion.