Flat Roof Drain

[greyam100]

Hi folks,

The drain on my 'flat' garage roof keeps getting blocked with bits of moss, leaves etc. Judging by the neighbours,' there used to be a filter on it but not since we bought the house.

This causes the water to back up and flood the roof, resulting in water seeping through the felt.

I'm looking to find a filter or something to try and prevent it getting blocked. Any ideas?

Photos of the drain are here (one shows the neghbours roof where the drain has a white cap on it

//www.diynot.com/network/user_album_update.php?album_id=22488

Thanks in advance

 

[Burnerman]

You are looking for a soil or drain vent cowl - but they do block up just as much and if there's a lot of moss etc up there, do be prepared to clean it out from time to time.
John

 

[greyam100]

thanks burnerman

do i just remove that screw in the middle of the existing strainer and take it out then pop a push-fit cowl in?

not sure if that existing bit comes out, it might be sealed in with the felt

 

[Nige F]

Yes remove the screw - get a wire cage for a soil pipe , that`ll fit best

 

[ree]

I suspect that you have permanent, weeping leaks thro cracks at the inside corners in Pic 1.

The felt is swollen (moisture gas) at the base of the parapet and looking very weathered.

Given the volume of water discharging onto your roof i doubt that filtering out debris will do much for you in the long run. Running guttering across the whole eaves of the pitched roof will remove a substantial amount of rainwater discharging onto your flat roof.

Does water from the flat roof garages to the right run down to drain on your and your immediate neighbour's roofs?

When its time for a new flat roof (pretty soon) you should attempt to co-ordinate the work with the other flat roof owners. Eliminating roof drains and re-jigging the roof falls to fascia and guttering might make more long term sense than the present "parapet" arrangements?