[Greenbuilding] Tyvek vs. tarpaper, over cedar siding? Alternatives

[Alan Abrams]

<We've gone back to tar paper because of reports that Tyvek crumbles 
over time.>  

I've read some discussion that the oils in cedar degrade tyvek; the
recommendation is the use of furring strips to hold the siding off the
surface of the membrane--which is good rainscreen practice, regardless--and
which has become our standard for any kind of siding.  One also need to note
the many grades of putatively designated 15# felt--apparently what passes
these days is not the same stuff used in the Good Old Days.

Alan Abrams