What Type Of Gravel Is Required For Flat Roof (Felt)

[newbie99]

I have installed another layer of felt on the flat roof. And I wonder what type of gravel or stones is needed?
I went o a DIY merchant today and ask if the chipped limestones (10mm) are suitable and the salesman said no and ask me to find a building material supplier. When I looked at another supplier they sell chipped limestones and described as suitable for flat roof felt.
So I am not too sure what to get now. Ideally I wants the rounded type of small stones to avoid sharp edges piercing the felt when step on.
Any recommendations will be appreciated..

[-SharonA-]

Spoke to hubby about this and he says gravel is a no no. Gravel stops the flow of water as it won't run away quickly when it rains. He would paint the felt with bitumen. The more things you put on top of felt, the worse it becomes.

[newbie99]

I got mixed views with regards to laying gravel on flat roof.
Since I have some stand still water on the upstream of the flat roof,, I am thinking that if I lay some gravel that will make the water flow as I am raising the heigh. I am be wrong.

[The Builder]

No, Sharon's right. Gravel is no longer used on flat roofs. There really is no need for it.

Modern felt (probably the "torch-on" variety) needs no further finishing. There are all kinds of re-coatings available if needed.