[J187]

MDF treads...the only thing I would do with them is cover them again or replace them with wood. There is no way the edge of a mdf stair tread is not going to begin chipping off .

Agreed. You either have to replace them or carpet them again IMO. MDF was used for treads as a cheap alternative STRICTLY for carpeting purposes and was never intended for finished wood application. Aside from possible chipping you will face other problems - MDF likes to swell and warp. Without sealing them 100%, even everyday spills and cleaning are likely to eventually swell your steps. MDF's arch enemy is moisture, not a good quality for a stair tread material... Also, without thick carpeting, MDF tends to creak a lot as well. Lastly, no matter what you do, as the others have elluded to, it will not look very good as a finished wood.

 

[J187]

I think laying down oak over the MDF is only going to muffle a squeek. I think its thick carpet or total replacement.

Joe - good point about the risers.. they may or may not be MDF. We'll have to see what the OP says. IF they are, it may be time to replace it all.

There are ways to save money, but I don't agree with this one. This is an example of builders not considering future use of a home, build for the now. Its one of those things that tries to save money and ends up costing money - great to lower the costs at first, but then when either the house is sold or the homeowner changes their mind about having carpet, they have to change out the stairs when ordinarily the stairs would have been good for many more years if oak was used in the first place.