Trailer Bunk Board Wood

[linchuntao]

Need to replace trailer bunk board for my 195CC. I can buy following 2"x6"x10' board from the local Homedepot/Lowes/lumber yard:

Pressure Treated Douglas Fir: sap wood, some imperfections

Non PT:
Green Douglas Fir: sap wood
Redwood: heart S4S with some knots. Overall condition is better than douglas fir.
Cedar: clear heart S4S. Perfect condition.

I did some research. Seems that cedar and redwood are little bit better rot resistant than douglas fir, but douglas fir has more structural strength .

Any suggestion which one I should choose?

 

[Harper]

I'd use the PT doug fir. But try to find with NO imperfections. Or at least choose your board carefully to avoid any knots in critical locations. What would be acceptable in the building trade, might not be to your application, since they are usually used on edge in building. Some imperfections could make it too weak laid flat. I don't think the cedar or the redwood have anywhere near the strength you'll need in a flat configuration.

 

[djnolan]

I used salt treated lumber which I assumed was pressure-treated Douglas fir. However you probably want to look for knots that run across the long edge of the board and stay away from those because when I did a post-mortem on my old broken Bunk Boards that's where they had broken.

 

[linchuntao]

Thank you guys.
Anybody know what wood is the original trailer bunk board? Mine seems not PT wood but I don't know it's original or not. I bought it used.

 

[Shallowminded]

No idea on the original but go to a marine supply house. They usually let you go out in the yard and pick your boards. I built my lift bunks with them. Seven years of heavy use and going strong. Can't imagine why they wouldn't last forever on a trailer. I don't think I would try cedar or redwood.