wrote:
I've looked in to this and it looks straightforward enough that me and
a friend could replace my rubber roof with new EPDM.

My question is that I know it has a slight pitch to direct rain water
towards the drain, but what was used to shape the roof? When I bought
the house the inspector said something about foamboard? I was
thinking of using wedges to nail to the top of the joists that the
underlayment will lay on...It would be easy enough to create the
slight pitch that way.

Mike

GAF and many other companies make foam board insulation and wedge
shaped foamboard to provide slope. We use it all the time on
commercial buildings to form the slope. Either that, or the roof
is framed using standard roof joist systems which are then built
up with wedge cut members to slope the roof, which is then
decked. The foam board can then be used for insulation and the
roofing material goes over that.

Here is an example of sloped foamboard:

http://www.gaf.com/Content/Documents/1040.pdf

--
Robert Allison
Rimshot, Inc.
Georgetown, TX