what is a suitable type of gravel to go on top of my flat roof?

Go to your local flat roof supplier, we use Siddals in Sheffield and buy a couple of bags of new gravel. Note you can sweep of your ould gravel, wash it and relay it. It is there to prtect your roof from the sun UV. If your felt is 15 years old be carefull as this is probably coming to the end of its usefull life and will be brittle.
Take care at height.

David Dean roofing Sheffield
April 2010

I've done a few in the past and they are laid on hot pitch followed by a second 'overcoat' of stones to a depth of 1" and as Mick says it's for fire protection take them away you end up with fire hazard.

1st. Check with Building control [Refers UK only] the cover requirements.
2nd. Check with property Building insurance explain what you want to do as you may be contravening the cover removing the fire barrier stone layer from the felt roof.
3rd. You can get various coloured stone but must be max 3/8" min 1/4" to give maximum cover without voids and at least 1" depth.
Using large stones leaves expose felt voids.
I doubt the paint suggested by Mick would be fireproof or accepted coverage by Building control or the insurance company and may even enhance a fire.

Bob
March 2010

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