De-squeaking a staircase (with sprayfoam?)

[Dan Friedrichs]

My folks have a 100+ year old farmhouse, and the main staircase squeaks horribly. It's poorly built, with little support on one side, constructed of several thin boards butted together, etc. That said, if you look at it, it looks amazing. They've refinished all the original oak floors, trim, and stairs in the house, and would never consider replacing this staircase and/or making substantial changes to it (mostly for historical reasons).

There is access to the backside of this staircase, though, and they have tried everything imaginable to quell the squeaks (screws everywhere, glue on everything, etc). I know that the correct solution is to identify which pieces are rubbing and apply glue/screws to prevent this, but there are SO MANY squeaks, and so little material to drive screws into, that I don't think any amount of effort will yield results.

My crazy thought: what if the entire back side of the staircase was sprayed with several inches of spray foam insulation (or some similar material)? It would add some rigidity (reducing movement of pieces against each other), and dampen the noise when pieces do move. Any thoughts or other suggestions?

[Bill Cunningham]

I don't think spray foam, which also has flexibilty, would work.. Perhaps a good thick spray on layer of two part epoxy to bond the wood together?
Personally I think the squeaks of an old staircase add to the charm. I don't think I have ever climbed an old staircase that didn't squeak. On the security side, they can also tip you off to intruders sneaking up your stairs in the dead of night

[David G Baker]

Wonder if a spray wax would help? If the squeaks are lubricated they might be a little quieter.

[Stephen Tashiro]

If the point is to keep the staircase in its original state, it would be worthwhile to thoroughly investigate what that state was. Perhaps some posts or bracing of the original were removed when someone "improved" it.

[Lee Schierer]

I think all you will get with spray foam is a squeaky mess that you can no longer easily see or work on. You need to address the squeaks one at a time. You may need to place custom shims under areas to prevent movement taking care that you don't raise up the treads. You will probably want to remove many of the old patches to get to the root of the problem.

[Prashun Patel]

The recommended solution for squeaky floors is often to put cross bracing between the joists; instead of attacking the friction points, you make a more stable structure that doesn't move.

Can you add cross bracing under the stairwell? Just guessing here.

[Chuck Wintle]

could the stair case be dismantled carefully, then rebuilt using more glue, screws and bracing as is necessary?

[Michael Weber]

Try talcum power. Really! If the boards are squeaking because they are rubbing against one another this may at least temporarily solve the issue. Sprinkle a heathy amount on the stairs and try to sweep between any boards. Powered graphite can be used for longer results. Worth a try.
http://www.doityourself.com/stry/silencesqueakyfloor.

[Wayne Hendrix]

In situations where you couldn't access from above I saw my uncle put a bead of liquid nails or similar construction adhesive along each side of the joist squeazing as much as possible between the joist and flooring above and then angle screws through the joist and into the flooring. That always seemed to work pretty good.

[Dan Friedrichs]

Thanks for all the advice. Mostly I was concerned about what Lee said - turning it into a mess that couldn't be accessed.

Despite my reservations that it's even possible, I will try to fix it the "proper" way - seeing if adding additional structural reinforcements is possible, and gluing and screwing rubbing members together.