laying engineered hardwood over rough ply sub

We’ve lifted all flooring in 70s ranch house and the hall was tiled...w industrial strength adhesive .getting it up was a chore and the surface is still a bit rough... cement bits, pock marks in wood sub etc. unsure if i should slowly try to chip away at every raised point, rent some sort of grinding sander to get the surface more level and ready for the vapor/floor install, or even consider cutting it out and replacing the sub floor (about 9’x 14’)... no idea how hard that might be. looking for most economical option....

Also... we are doing nail down install...i have a finish nailer and i wonder if i definitely need to rent a flooring nailer, or if i can use mine.... is that a definitely no no? i used it once before for flooring and seems to have held up fine but it was a very small project (stair landing) and this is 1200 sq ft...the flooring is a thinner variety than some i viewed... builder grade, w ply sub layers. Thanks in advance for any advice!

 

Every flooring material has a min levelness requirement, but I can say that that applies t the overall floor to resolve any high or low spots. What you have is an issue just to get the floor clean enough to take that measurement.

I cant say what is best/easy/fastest option, you have eyes on the project.

As far as fastening, again that is a requirement for the specific floor itself so you cant just assume what you have will work. Some of the thinner engineered products use staples, thicker flooring use cleats.

In my opinion it's cheaper to just buy the tool needed, by the time you add up the cost of renting, plus the in conveyance factor having that tool available when your ready is best option.

 

Buy the tool, do the job, sell the tool at a reasonable cost.
Has always ended up a lot cheaper for me on any decent sized job than renting the tool.