Removing mortar bed
Hi. I am in an upstairs condo with a mortar or mud bed under all the flooring. I have various squeaks and thumps when I walk around the place and would like to fix that before I tile the bathroom and recarpet the rest. It looks like I would need to remove all the mortar bed and then replace the nails in the subfloor with screws. I believe the mortar bed is there for fireproofing between the upper and lower unit, as well as sound deadening. Is that correct? What happens if I leave the mortar bed out? I am checking with the city to see if code requires it to be there. Finally, what type of contractor would I look for to replace the mortar bed, and is it expensive?
Thanks for any information you can offer.