enclosed flat roof drainage, free money

[mik745]

I am in the process of building and extension.

Oh the free money is to get you to read the post, sorry no free money

I am putting in a GRP roof (old school fibreglass)

issue

The roof is flat
There will be a 300 mm wide wall all the way round.

IT WILL FILL WITH WATER when is rains!!!! upper floor cold swiming pool

What is the best way to sort this out?

The area is about 50m2 I have a drainage point at the middle.
Was thinking of putting a 150mm pipe thru the wall and fibreglassing the bottom to the deck, to an external drainpipe

ideas please

 

[freddiemercurystwin]

You're there in principal, presumably you mean a 300mm high parapet wall round the perimeter? A two way outlet is designed for the job, eg http://roofingsupastore.com/product...flow-100mm-two-way-rainwater-outlet.htmlwhich then drains into a hopper and a downpipe, don't try making something yourself or it'll end in tears. That'll be £10 thanks!

http://roofingsupastore.com/user/u/files/Caro Outlets Brochure.pdf

Might be worth having an overflow somewhere else in the parapet so that you know if the outlet ever gets blocked up unless you can see the roof from a window.

 

[mik745]

Thanks Freddy

I found the way I want/need to do it, parapet outlet, simple really

bout £25 for an outlet, does exactly what I need