We had our interior steps to the second floor redone a few years back with new oak, pre-finished risers and treads. Now two of the treads pop every time you step on them. Let me be clear, it's not a squeak - it's a pop. We've lived with this for several years and I simply can't stand it anymore. The underside of this stairwell is directly over the steps to our unfinished basement stairwell, but it is covered. I'd bet it's plaster since the whole house was plaster originally. Oh, it's not a seasonal thing either - they pop no matter what the temperature or moisture level is in the house - year round! We try to step on the extreme outside edge to and as lightly as possible, but even that isn't working anymore. So pretty much wherever you step you get that POP on two of the treads. The stairs are not covered - we like the hardwood look and feel. Is there anything we can do to fix this without marring the treads too horribly? The House was built in the mid-50s. It's your basic Cape construction. - Thanks