Flat Felt Roof - gravel chippings needed?

Mr_K

Finally got around to getting my felt roof redone on my small flat roof extension. Been patching it up for years, but can't stand another winter of that !

Found a reputable roofer and agreed a quote. He's not costed in any gravel chippings ( my Roof currently has them on top). He said they're not needed and personally he wouldn't bother. But they can be added for a cost. 

So are they needed or just cosmetic these days? Are modern felts more robust? 

FreeBear

Don't have chippings on my roof - If anything, they can be a royal pain in the [redacted]. They get washed off the roof and block up the gutter & soakaway.

If you are having the whole roof refelted, it is well worth upgrading the insulation - In fact, building regulations require it if it is technically feasible. You should also be getting the work signed off either by an approved contractor that can self certify, or by Building Control. Few people bother... Rules are a little different up in Scotland, so feel free to check.

Apodemus

The term "refelted" is often used to cover a range of different roof coverings.  Do you really mean old-fashioned roofing felt, or a more modern membrane?  Chips can help protect old-style felt (and the tarry junctions) from UV or heat from the sun but most modern membrane coverings are more UV resistant.  So the answer to your question may depend on what actual covering you are getting.

Also gravel chippings come in different types.  I agree with FreeBear that small sharp gravel types can be a pain, but larger, rounded gravel works better. 

gm0

The layout scale and drainage can also be a factor. 

I recall a flat roof which had stones on it which was later replaced with a different membrane due to defects but without stones on the replacement that was installed.

This lack of stones introduced flying sheets of water blown over the edge in stronger winds and rain in combination where water was arriving on the roof and squalls were blowing it off onto balconies and down the side of the structure. It was well above ground floor level so arguably more extreme conditions than typically found in a ground floor extension

I was also unconvinced that the thermals and acoustics were the same without the rocks - certainly not improved by the change.

So depending on heights. topology and site exposure there are these other factors to at least consider.

greensalad

I was told solar chippings are no longer required due to improved roof felting stuff. At least I didn't have any put on mine.