We have just begun some work on our older house.
Our contractor is correcting supports to floor beams/joist in the basement of our old house. In the house's oldest section, he found cement in the ceiling (or the first floor subfloor. That cement is about 3 inches deep and is supported by very old wood plant subflooring. I understood him to say that he has not seen cement used in a ceiling with a basement underneath before. He says because the cement is in contact with wood that it is not up to code and he needs to jackhammer all of it out. Further he cannot guarantee what will happen cement and to our upstairs doors and windows, if he continues with installing jack posts in this area. Some of the cement was exposed/without wood subflooring support, had been chipped away and did crumbled when they begain installing jack post in that area. The rest is hidden behing the plank subfloor and the condition right now is unknown. He estimates the area with cement is about 12' by 12' which would on the first floor is one small room, wall and closet space between the small room and another room.
I understand from another members post (in Victorian bath remodel) that cement or 3" mortar over wood subfloor while maybe not common is not unheard of, and that he had found it in houses from the 50's and 60's.
Does anyone else have more information or experience with this old construction method? Why was it used?
Is there a difference between 'cement' 'mortar' and "rock lathe"? all of which seem to have been referred in various posts discussing "cement" in second story subflooring in older homes.
Does the cement need to be jackhammered out? What does that involve? What other potential other issues does removing it cause? What additional repairs may we likely face if the cement is removed?
If jackhammered from the basement, the old wood plank will be destroyed..is that lose?
If it needs to be removed from above, that involves removing old hardwood flooring (a selling point for us for the house) and walls of the closet and room..less of a lose?, unless we want to reconfigure the rooms upstairs?
Any thoughts, information, suggestions, ideas of what we should be thinking about or asking will help.