Water pooling on my new flat roof

[Ben100]

Hi all, I’ve just had my new flat roof installed but water seems to be pooling in the corner by the gutter. Is this an issue or something I shouldn’t worry about? I’ve checked for any blockages but there’s nothing stopping the water going into the gutter. It just looks like there is a dip the water is collecting in.

[tonyshouse]

Where is the outlet? Is there a sluice in case it blocks? 
 

puddles on flat roofs are in my opinion unacceptable 

[nod]

Puddles are unavoidable and will soon dry out 

[Ben100]

39 minutes ago, tonyshouse said:

Where is the outlet? Is there a sluice in case it blocks? 
 

puddles on flat roofs are in my opinion unacceptable 

The outlet is in the far corner, through the parapet wall. It’s still under construction, so it’s just a lead outlet at the moment.

 

I'm not keen on the water pooling here. Maybe it can be fixed with some more layers of felt or resin?

[Ben100]

10 minutes ago, nod said:

Puddles are unavoidable and will soon dry out 

It does have a fall, so it shouldn’t pool. I think it’s a dip in the roof there.

[markc]

If the outlet is in that corner then it’s probably just being held back by the membrane and a bit of leave debris. If the outlet is in another corner then you have a dip … how deep is the puddle?

[Ben100]

10 minutes ago, markc said:

If the outlet is in that corner then it’s probably just being held back by the membrane and a bit of leave debris. If the outlet is in another corner then you have a dip … how deep is the puddle?

The outlet is in that corner. I've checked, there's nothing holding it back. The membrane is above the felt. It's definitely a dip, probably around 15mm deep.

Edited November 27, 2021 by Ben100

[saveasteading]

2 hours ago, nod said:

Puddles are unavoidable and will soon dry out 

 

I don't agree. They are avoidable and it might take weeks to dry out.

If this is new build then it is unacceptable and should be remedied, and not by patching.

 

What does the design say the slope should be?

Whatever, the fact appears to be that part of your roof has negative slope, and cannot drain until the water is 15mm deep.

[nod]

2 hours ago, Ben100 said:

It does have a fall, so it shouldn’t pool. I think it’s a dip in the roof there.

Most of the large commercial roofs are like ponds But still passed 

Without putting a steep fall on it It’s difficult to avoid 

[Mr Punter]

You often see puddles near outlets.  Often there is lead fitted around the outlet adding a few mm then some extra membrane adding a bit more.