Home is built in California late 1990s. I recently removed some nails and screwed subfloor on 2nd floor to joint/stud below using yellow zinc plated screws from HomeDepot. Now I realized it has notes this screw is only for non-structural and should not be used on treated lumbers (what woods are considered to be treated?)

Is it a problem to screw yellow zinc plated screw to stud and subfloor? (will it corrode? what does it mean by corrode? will it cause damages to structure over a long time?)


Appreciate your answers!

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    Treated wood refers to pressure treated exterior use and ground contact wood. The chemicals used to make the wood rot resistant will corrode screws and nails unless they are coated and specified for use with pressure treated wood – Kris May 9 '19 at 3:39
  • Thanks Kris, when it corrode screws, will it also make wood weak such that wood will get damaged? or just screw threads will not work properly? – DIYstress May 9 '19 at 18:25
  • Since the wood you are working with is not treated you have no reason for concern. If it was treated wood the chemicals would rust the yellow zinc plated screw and cause it to fail. – Kris May 9 '19 at 18:30
  • Thanks for quick response! So wood in the picture does not appear to be treated? This worry has been keeping me awake late :( – DIYstress May 9 '19 at 19:03

The lumber on the second floor is unlikely to be treated. And holding flooring down isn’t the toughest application, so that wouldn’t be an issue. The screws you linked to would be acceptable for this application.

  • Thank you so much for the comment. I added picture of stud below the 2nd floor (removed recessed light and took video from underneath). Is there any way to tell if the woods are treated or not? Also, will corrosion basically make screw malfunction or will it be severe enough to damage the wood to crack (if it is treated wood)? Thanks! – DIYstress May 9 '19 at 18:23
  • @DIYstress It does not look like treated lumber to me and my understanding is that a non-coated screw in treated lumber will basically rust/erode into nothingness in time. I don't know how much time, but I would think it would be a year or two in an outdoors environment. – UnhandledExcepSean May 9 '19 at 19:20
  • Can confirm that is not treated lumber. (So corrosion isn't an issue.) And to reiterate, those screws are not in a 'structural' use, so are perfectly acceptable. – Aloysius Defenestrate May 10 '19 at 4:11
  • Thank you all! Finally relieved :) – DIYstress May 10 '19 at 5:00

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