there are so many tipes of gravel out there now,all different colours and shapes. the idea of putting gravel on flat roofs was to stop sparks landing on the roof and starting a fire. " their is silver fire proof paint out there now , thats is painted on the roof , you might get this fire proof paint in black , or other colours. thats if you dont want to use stone, if you want to use pebbles" get the rounded 1inch, in any coloure you like , from any big diy store , just rember what their job is and what they are use for. but me i would take them all off , and check the roof felt" for rips ect , fix them and paint it fire proof silver..
mick, March 2010