I have a rental unit with solid red oak hardwood floors. My wife and I completely refinished this flooring three years ago; filled and sanded, sealed, then applied two coats of polyurethane finish with lambskin pad. We had no problems with this for the first tenants that rented. Two years ago they moved out and we had new tenants move in, and then we started having flooring problems. One problem we just discovered a few days ago is that the floor finish has actually "disappeared" from the entire outside perimeter of the floors and under some furniture that is against outside walls. There is no apparent water staining, the finish is just disappeared down to exposed bare wood.

Although we do have some apparent water and pet damage in other areas of the floors (that we are addressing now), the flooring in the hallway and inside closets show no issues with the finish "disappearing".

This house also has oil-fired baseboard hot water heating with the baseboard heating running along outside walls. These particular tenants refuse to use the installed oil-fired heating and instead use electric space heaters during the winter. The way the finish has disappeared I am wondering if, during the winters when they are using space heaters, condensation built up on the flooring around the perimeter of the house and caused the finish to deteriorate due to constant high moisture.

I would greatly appreciate an expert opinion on this.

Nothing wrong with using electric space heaters. Propane yes, but they might be dead from the carbon monoxide.

It is either peeling away or worn away from cleaning , usage ,etc.

the heaters aren't doing anything..

This is odd. Most times the first areas to wear off would be high traffic areas, and from the sounds of it this is in probably the least traffic areas. My thoughts for the cause of this would that maybe the edges were not sanded evenly with the rest of the floor which may have caused the finish to soak in a bit more in these areas. Therefore their would be less of a top layer of finish. This is just a guess. maybe consider recoating the floors and since it is a rental use a few coats of a commercial grade finish.

Thank you folks for your replies.

Ron