I am building a houseboat and I am torn between using 5/4 deck boards or just using 2x6s for deck boards. My joists are on 20” centers. My main issue is I am wanting to save on weight because I only have so much buoyancy. The 5/4s boards will be significantly lighter than using the 2x6s. Anyone have any input on this ? Thanks!

  • I suspect having closer joists would give desired rigidity for cheaper in weight than 2x6s Jun 16, 2023 at 5:03
  • Yea I am aware of that. The platform is already assembled at 20” center. Jun 16, 2023 at 10:26

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Based on my house's deck built by a previous occupant, 5/4 did fine to span 24" joists. It was a bit springy, but it was fine. Though I'd check the mfgr specs on the specific 5/4 you're planning on using to confirm that 20" span is within spec.

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