DIY Treating Untreated Lumber for Deck Usage? – GreenBuildingAdvisor

Replies

1. 

   walta100 | Apr 25, 2025 11:05am | #1

   My guess is the cost of any affective product will exceed the cost of new TP lumber. Consider how much work it would be if the boards did rot after you treated them. The risk VS rewards does not work for me.

   Walta

2. 

   user-5946022 | Apr 25, 2025 10:34pm | #2

   Second @Walta100’s comment. Do not frame a deck out of untreated 2×10’s

   Chances are that your ceiling joists are 2×8’s or 2×10’s. If you have a vented attic, current code required insulation (or more than code required) is going to be thicker than the ceiling joist height and thus the joists are buried under the insulation. This makes it difficult to move around the attic for maintenance issues. You can cut your extra 2×10’s and install them perpendicular to the ceiling joists to create small paths from the attic access to any attic elements such as a radon vent, or to create storage areas near the attic access. Use some extra floor decking to deck it the paths and storage area…

3. GBA Editor

   MALCOLM TAYLOR | Apr 25, 2025 10:53pm | #3

   Tim_O,

   Surface applied treatments should be reserved for sealing field cuts in PT lumber.