I am in the process of installing an engineered wood floor on concrete.  It is not advised to install traditional flooring over concrete, as the moisture in the concrete tends to warp the floor.  Engineered floors are more resilient to this situation.

I made the incorrect assumption that the waterproof glue used to adhere the wood floor to the concrete would be sufficient to bind the threshold to the rest of the floor.  I was incorrect.

The glue used is incredibly powerful and I needed to figure out a way to remove the old threshold and correct the problem.  I originally considered using a Multimaster saw, but I was concerned that it would damage both the floor and the adjoining bathroom tile.

A router seemed like a safer solution, and it worked wonderfully in this particular application.

The first picture shows how the floor had risen up causing an uneven surface. The rest of the pictures show the photo-story of the repair.

The use of a router in this particular application prevented additional floor damage.  I am very happy with the results.

Next step: sanding and finishing!

The floor had risen above the threshold.

Ready to cut away the old threshold.

Prying out the old threshold.

Old Threshold removed. The glue was so powerful that it took off some of the concrete.

The router bit used to cut the grove.

Spline inserted.

Preparing the waterproof adhesive.

The newly installed threshold.