Water table with rain-screen: to fur or not?
As I’ve mentioned elsewhere, I’m currently tearing off my old LP OSB siding in preparation for replacement with a rain-screen wall and Hardieboard (ColorPlus). I’ve been reading around the web about rain-screen strategies and something has caught my eye: when using a water table, some builders run their furring all the way down to the sill plate and install their water table board against the furring, so that the drainage plane runs down behind the water table. One example is this article from FHB: https://www.finehomebuilding.com/how-to/articles/siding-with-rain-screen-walls.aspx?ac=ts&ra=fp
Other builders install the water table directly to the sheathing, top it with metal or PVC cap flashing, then begin the furring and rain-screen wall above the water table, a la this article from JLC: http://www.nyashi.com/newsletter/2006/May%20Files/Rain%20screen.pdf
Oddly enough (?), while the authors of the latter article install their water table directly against the sheathing, they go out of their way to include window trim in their rain-screen, placing furring strips (or furring “blocks” as they call them) behind the window and door trim as well. I don’t plan to go that far, but I wonder about the water table; would you build it out on the furring, or against the sheathing and begin the furring above it?
(FWIW, I’m making my water table from WRC).
Replies
I don't understand -- what's the point of a water table if the drainage plane runs behind it? Where does the water eventually exit?
That was my same exact thought; I thought a water table was there to shed water, so if you put the drainage plane behind it, you're basically using the water table for decoration. But that article in FHB shows them doing it that way, so . . .