Mike Lamb 14 Report post Posted May 14 This lumber is being used for an outside deck. It looks like standard construction grade and nothing that should be used outside. Do these stamps determine location use? I did a quick walk-by and will look at the house tomorrow. Typical pressure-treated lumber is tagged at the end of each piece with treatment info. Share this post Link to post Share on other sites
John Kogel 19 Report post Posted May 14 I think you are right, no mention of pressure treatment in those stamps. HT stands for heat treated. Share this post Link to post Share on other sites
Trent Tarter 2 Report post Posted May 14 As far as I know there's nothing stating that it cant' be used. It just needs to be well stained and sealed. I see quite a few decks built with untreated wood, personally I would use treated wood for the joists and beams. Share this post Link to post Share on other sites
Jim Katen 35 Report post Posted May 15 It's required by the IRC in section 317.1 Share this post Link to post Share on other sites
