In Bowman's view, earth-covered roofs “allow a foot-thick layer of life to continue life's struggles for another day.” To prepare his homes (including the one shown here) for the onslaught, Bowman specs Grace Construction's Hydroduct 660 drainage composite sheet and Bituthene 4000 pre-formed waterproof membrane, which has a self-adhesive rubberized asphalt compound to protect the roof from leaks. Thus fortified, site topsoil removed during construction “is simply relocated several feet atop the roof structure,” Bowman says. Grace Construction Products, 866.333.3726;


Obie G. Bowman, Architect
obie bowman, faia
healdsburg, calif.