What is the difference between an internal and external drain outlet?

GRP Outlets (Internal & Parapet)

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Divert water off your roof the right way

GRP outlets are made from glass-reinforced plastic – which is known to most people as fibreglass. These are highly durable and ensure rainwater drainage on flat roofs, through walls and parapets, even in extreme weather conditions such as heavy rain, high winds and snow.

There are two main types of GRP outlets – internal drain outlets and through-wall/parapet outlets.

Internal drain outlets – These are installed vertically through the roof deck, connecting to a downpipe which drains the water to the ground. Whilst these can be more complex to install, they tend to be more aesthetically pleasing and provide protection to the drainpipe in extreme weather conditions.
Through-wall/Parapet Outlets – These are installed through a parapet wall and connect to a downpipe on the outside of the wall. These are easier to install compared to internal drain outlets, however, the downpipe is exposed to extreme weather conditions which may require more frequent maintenance.

At UKFR, we supply highly reliable GRP outlets suitable for a wide range of gutter installations to suit your needs.

For Internal Drain Outlets:

GRP Vertical Drain Outlet

For Parapet Drain Outlets:

If you need any help finding the right one, please get in touch with us today and we’ll be on hand to assist.

We also have the GRP Roof Vent for ventilating cold deck roofs.

If you’re installing a GRP roof, make sure to check out our full range including GRP trims, GRP tools or for EPDM rubber roofs take a look at our rubber gutter kits featuring everything you’ll need for a safe and reliable installation.

Why Buy GRP Outlets From UKFR?

At UKFR, we make it our mission to provide reliable & long-lasting GRP drainage solutions to happy customers all across the UK. With an “Excellent” trust pilot rating achieved across our product range, customer service and delivery, you can be fully confident when shopping online with us. Shop with UKFR today!

An internal drain outlet is built into the floor of your deck and connects to a downpipe to discreetly remove rainwater from the roof.

An external drain outlet goes through an external wall and connects to a visible downpipe to remove rainwater from the roof.

Divert water off your roof the right way

There are two main types of GRP outlets – internal drain outlets and through-wall/parapet outlets.

Internal drain outlets – These are installed vertically through the roof deck, connecting to a downpipe which drains the water to the ground. Whilst these can be more complex to install, they tend to be more aesthetically pleasing and provide protection to the drainpipe in extreme weather conditions.

Through-wall/Parapet Outlets – These are installed through a parapet wall and connect to a downpipe on the outside of the wall. These are easier to install compared to internal drain outlets, however, the downpipe is exposed to extreme weather conditions which may require more frequent maintenance.

At UKFR, we supply highly reliable GRP outlets suitable for a wide range of gutter installations to suit your needs.

For Internal Drain Outlets:

For Parapet Drain Outlets:

If you need any help finding the right one, please get in touch with us today and we’ll be on hand to assist.

We also have the GRP Roof Vent for ventilating cold deck roofs.

Why Buy GRP Outlets From UKFR?

Frequently Asked Questions

An internal drain outlet is built into the floor of your deck and connects to a downpipe to discreetly remove rainwater from the roof.

An external drain outlet goes through an external wall and connects to a visible downpipe to remove rainwater from the roof.