Help needed on flat roof low spot

[deanogtv]

We moved into our house around 2 years ago now in which time I have managed to refub every room in the house. Being a 1970s build house the exterior is pretty bland so this is my next long term project. The house has a small hall way entrance with a cloak room which leads into a converted garage all of which is contained under a front roof. The garage was converted around 4 years ago and i’m pretty sure the flat roof was replaced then with an roofing felt system, excuse my non builder terms here. Its water tight and functions fine. However there is a large low spot which does not drain, its about 5-7 mm lower than the drainage hole. In the winter water will sit there for weeks on end. I’m guessing in the long term this isn’t good. To solve this I need to ideally raise this level to stop water ponding here, but what can I do to do this cheaply.
Would a shingle help displace the water?? I’m guessing I would want a lite covering which will not add weight and depress the low spot further.
Next door have shingle and a moss covering, I’m guessing the moss has grown naturally over time.

Here is a street view before the garage conversation, I'm the house on the right.

[barryrs]

In most cases a small amount of ponding on a flat room isnt a problem so lang as the roof structure is sound.

A thin layer of gravel over the top will help protect the roof covering from UV damage and will help aid evaporation so might be worth considering.

[Paul Drawmer]

Roofer will be along in a minute I expect...

But I think it depends on what covering is on the roof. If it's Rubber (EDPM) then pooling won't matter and shingle won't help.

If it's traditional felt, it should have a fall to remove surface water and shingle will help protect the felt.

[deanogtv]

Its not rubber, its definitely felt.
I have read that the shingle protects the felt which I may cover just to help anyway and I'm guess the shingle will help to displace the ponding water anyway.

Should I use normal pea shingle, 5mm stone for a builders yard??

[roofer]

As Barry, if it's mineral finish felt, it needs nothing. Shingle/ chippings don't disperse the water, they hide it.

[paulwirral]

Chippings , the cowboy felters best friend , 2 layers of cheap underlay , if your lucky , and chuck some gravel on to cover the mess up , keeps it cool is what they used to say !
That's what they used to do back in the day in the north east anyway !