Abstract: The longitudinal sides of rectangular wood roofing shakes are stepped providing transversely extending shoulders facing the shake tips and dividing each shake into a narrower tip portion and a wider butt portion. In application, rectangular fillers are located between the tip portions of adjacent shakes with the butts of such fillers tightly abutting the shake shoulders. The width of each filler is substantially greater than the combined depths of the shake shoulders it abuts such that the adjacent longitudinal sides of the butt portions of the shakes are spaced apart a substantial distance.