loose chippings on a flat roof

Morty_007

Hi all,
I have 2 simple (ish! I hope) questions about my flat roof.

First of all what are the loose chippings on it likely to be? (used as a roof terrace to sit on etc and not just a roof, if you see what I mean) Thay are blackish type stones.

And second of all, its covered in quite a lot of moss, it is possible that I could just brush the loose chippings and moss off and replace with another layer of loose chippings? They all seem to be loose, ie not held or glued down with anything.

Many thanks in advance

Morty

courtjester

The chippings are there to protect the pliable roof surface (normally bitumen felt, but could be more substantial asphalt if you are using as a terrace) from the ageing effects (drying /perishing /cracking) of sunlight. Thus they will prolong the life of the roof, so should be replaced if you sweep the existing ones off.

They are probably black due to dirt and /or fungal growth. A builders merchant would be able to supply suitable replacement.

It's a good idea to get rid of the moss as this can deteriorate the surface also and permit build up of water-pooling. You could instead of sweeping it all off, simply use some moss-killer solution.

Morty_007

excellent, very helpful. Thank you very much.

I was going to sweep the whole lot up and replace it because I think we have probably lost a lot of chippings into the gutter and so need to replace some anyway. Getting rid of the moss this way is probably easiest too as a killer will kill it but leave the remains.. In for a penny, in for a pound and all that!
Cheers

greyteam1959

Be careful that you dont make a hole in the felt or else you will be up for more than a few chippings.
If you get a water you will have a right mess to sort out !!!!

Morty_007

mervyn11 wrote:

Be careful that you dont make a hole in the felt or else you will be up for more than a few chippings.
If you get a water you will have a right mess to sort out !!!!

Advice heeded, thanks :T