Replacing a split tread on an old staircase

Question

We have an old staircase (1900s) and after removing the carpet, before we get the new one fitted, we noticed that one of the corner steps has a lengthways split right down the middle:

How easy would it be replace the step? Or alternatively would it be possible to toughen it up? One person suggested to use a thin piece of hardboard on top of it to spread the load.

I have booked out a joiner for tomorrow morning but now wondering whether I should just leave the step alone. I haven't used the joiner before so don't want him to just crash & burn to make some money so would really appreciate some advice. When I walk on the step it gives less than 1cm. There is no access to the stairs underneath.

Answer 1

If the tread is loose enough to close the gap by tapping it with a hammer you may be able to glue it .If it is loose take two 3/4x3/4 inch boards that are as long as the crack.Drill four holes thru both boards big enough for a 10-24 screw.With some dry wall screws attach the boards to the tread on both sides of the crack.Apply some gorilla glue to the gap. Using the 10-24 screws draw the gap closed, allow the glue to dry, remove the 3/4" boards.Sand any glue squeezed out.