Hello all,
I purchased a home that is around 90 years old. For some reason, there was a fireplace that was not vented to anything in the living room -- decorative, i suppose...

It was hideous, so I removed it. Of course, it was made of solid concrete and had two poured footings that the subfloor goes around -- about 2' x 2' each.

We have also removed the old flooring and are going to lay a new 3" solid maple prefinished floor from Tembec on top of the original subfloor (diagonal running 1x6 planks that we have put decking screws into through to the joists.)

My question: What do I do where the subfloor stops and bumpy-lumpy concrete starts? Do I chisel it down and put in self-levelling stuff to make it even with the subfloor? Any ideas?

Thanks -Jamie

we are assuming the balance of the subfloor is wood. So, you have some concrete subfloor surrounded by wood? You are nailing the floor?

This sounds like the footing for the brick fireplace, right? Unfortunately, you need a wood subfloor so you will need to jackhammer down a little ways then float it smooth with a cement based floor patch till it is 3/4" below the height of the existing subfloor. After the floor patch material is dry, then glue and screw (with Tapcons) new 3/4" plywood in this area. I've done this quite a few times.