Protecting floor joists resting on cement?

Old 07-10-18, 08:03 PM
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Protecting floor joists resting on cement?

I have to put floor joists over cement to make it level and the same height as the adjacent floor. 2x3s with shims are the correct height and the easiest so I don't have to rip a lot of 2x4s. Here's the question:

Only a couple of feet of each joist rest on the cement. If I use doug fir 2x3 will Sill Seal protect the joists from decay? Should I put down a moisture barrier too?

I thought about using 2x4 PT but then i have to rip a bunch of them or I could (or get the local lumber yard to) rip down redwood 2x8s into 1/3rds. I prefer using 2x3 doug fir. Suggestions?
Old 07-11-18, 04:36 AM
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I would use pressure treated lumber. If you can find it wood treated for ground contact would be best.

Yes, I would put down a moisture barrier. A strip of 6 mil plastic at the minimum.
Old 07-11-18, 09:04 AM
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Indoor, outdoor, above or below grade?

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