starting floor project with clean slate by using leveling compound
My house had a combination of carpet and tile. I got the tile up with a jack hammer with one of those wide flat thin chisel piece attachments. It was good with getting the thinset up but you can still see the trowel marking and it not completely smooth like a chalk board. So i was thinking that i just create a nice clean smooth floor by pouring some leveling compound over the entire floor so everything is consistent. Im covering about 600 sq feet of concrete sub floor so i dont know how expensive leveling compound is or how much a bag can generally cover. Does this sound like a good idea?
Also there was a strip of tar paper applied under a section of the tile i removed i suppose to cover up a foundation crack. something like 1ft x 12 feet strip of tar paper. Should I remove this tar paper or just level right over it with leveling compound?
Rob Self Levelling Compounds are miracle-drugs in some cases and work very well.
A single 50# bag will cover 50 square feet at 1/8" of thickness. In your case you should probably consider 1/4" of coverage because 1/8" of coverage would be difficult to deal with and spread accurately. You would also require the compatible primer first.
The roofing felt method of crack isolation has always been poo-poohed by the floor covering industry but it also has been known to work. This would depend primarily on what type of crack was being isolated. A small stress fracture would probably be okay but an expansion joint (crack) would be a different story and should be honored through to the surface.